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Abstract

Effective management of water quality in large rivers requires information on the influence of activities within the catchment (urban and rural) throughout the whole river basin. However, traditional water quality monitoring programmes undertaken by individual agencies normally relate to specific objectives, such as meeting quality criteria for wastewater discharges, and fail to provide information on basin-scale impacts, especially in transboundary river basins. Ideally, monitoring in large international river basins should be harmonised to provide a basin-scale assessment of sources and impacts of human activities, and the effectiveness of management actions. This paper examines current water quality issues in the Danube River Basin and evaluates the approach to water quality monitoring in the context of providing information for a basin-wide management plan. Lessons learned from the monitoring programme in the Danube are used to suggest alternative approaches that could result in more efficient generation of water quality data and provide new insights into causes and impacts of variations in water quality in other large international river basins.

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... Pearson correlation analyses were performed to test the correlations between the water quality parameters measured by both CEA and CONAGUA ( Figure 3) with a focus on the comparison of neighboring monitoring sites (Table 1) to test the pairwise observations made by these authorities [26]. The temporal resolution of both data sets (CONAGUA and CEA) was considered, and only temporally and spatially paired observations were used to test the comparability of the time-corresponding data in neighboring monitoring sites. ...
... CA is frequently used to find monitoring sites that respond similarly to different sources of pollution affecting water quality, as it allows determination of clusters of monitoring sites, where the within-cluster variance is minimized, and the between-cluster variance is maximized. The resulting clusters display low heterogeneity, while objects from different clusters would show high external heterogeneity [26]. The clustering criteria was the silhouette index, S i ∈ [−1, 1], which can estimate the goodness-of-fit and validate the number of clusters formed. ...
... The selection of appropriate monitoring sites is the most crucial task in designing WQMNs. Clustering analysis allowed for the assessment of similarities (and dissimilarities) among monitoring sites regarding their water quality features [26,32]. Figure 7 presents the resulting dendrogram for the combined set of monitoring sites from both WQMNs considering only the water quality parameters measured by both authorities (those in the blue region of Figure 3). ...
Article
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Water quality monitoring networks in the global south often display inefficiencies because monitoring strategies are frequently designed based on subjective professional judgments to define the temporal and spatial attributes of the networks, leading to poor cost–benefit relationships. The Lerma-Santiago Hydrological System (LSHS) in Mexico currently experiences severe environmental degradation caused by uncontrolled pollutant emissions from urban centers, agricultural, livestock, and industrial activities settled in the basin. While both the national and state authorities monitor this hydrological system, there has never been an effort to assess the monitoring efficiency of these two networks. The aim of the present study was to assess through multivariate statistical analyses the potential for coordination between these two interacting networks. For this purpose, two independent large water quality datasets with temporal and spatial attributes measured by two different authorities (the federal and the state) were used to identify those sites where coordination should be rationalized and those parameters that should continue to be monitored. The case study herein presented highlights the duplication in efforts to monitor surface water quality in the Lerma-Santiago hydrologic system, which implies a lack of coordination between the authorities and shows that water quality monitoring networks have not been reassessed since they were first implemented. Furthermore, using the case study of the Lerma-Santiago in Mexico, we expanded on various deficiencies, such as the use of different sampling frequencies and analytical methods by the authorities and inefficient communication among federal and state authorities. This study has revealed a large potential for coordinating two water quality monitoring networks (WQMN) in the Lerma-Santiago Hydrological System and a methodological approach that may be used to assess this potential. Coordination strategies for WQMNs can lead to significant cost reductions, extended network reach, and higher overall data quality in developing countries with limited financial resources and technical capabilities.
... Effective monitoring of water quality in large rivers provides adequate information on the impacts of activities within the catchment throughout a river basin as a whole. Traditional monitoring of water quality implemented by individual agencies usually relates to specific objectives, such as meeting quality standards for pollution discharges, and does not provide sufficient information on basin-scale impacts, particularly in large river basins (Chapman et al. 2016). Therefore, the greater the number of monitoring sites throughout the water body, the higher the probability that they accurately represent its current status (Chapman et al. 2016). ...
... Traditional monitoring of water quality implemented by individual agencies usually relates to specific objectives, such as meeting quality standards for pollution discharges, and does not provide sufficient information on basin-scale impacts, particularly in large river basins (Chapman et al. 2016). Therefore, the greater the number of monitoring sites throughout the water body, the higher the probability that they accurately represent its current status (Chapman et al. 2016). However, there are concerns about resource when a larger number of monitoring sites is required, hence a balance is needed to meet both resource and scientific requirements (Earle 2008). ...
... However, there are concerns about resource when a larger number of monitoring sites is required, hence a balance is needed to meet both resource and scientific requirements (Earle 2008). In this case, reducing the number of monitoring sites to the extent possible, in order to minimize the operational monitoring cost, is ideally the aim of the current tendency (Chapman et al. 2016). ...
Article
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Managers of water quality and water monitoring programs are often faced with constraints in terms of budget, time, and laboratory capacity for sample analysis. In such situation, the ideal solution is to reduce the number of sampling sites and/or monitored variables. In this case, selecting appropriate monitoring sites is a challenge. To overcome this problem, this study was conducted to statistically assess and identify the appropriate sampling stations of monitoring network under the monitored parameters. To achieve this goal, two sets of water quality data acquired from two different monitoring networks were used. The hierarchical agglomerative cluster analysis (HACA) were used to group stations with similar characteristics in the networks, the time series analysis was then performed to observe the temporal variation of water quality within the station clusters, and the geo-statistical analysis associated Kendall’s coefficient of concordance were finally applied to identify the most appropriate and least appropriate sampling stations. Based on the overall result, five stations were identified in the networks that contribute the most to the knowledge of water quality status of the entire river. In addition, five stations deemed less important were identified and could therefore be considered as redundant in the network. This result demonstrated that geo-statistical technique coupled with Kendall’s coefficient of concordance can be a reliable method for water resource managers to identify appropriate sampling sites in a river monitoring network.
... With high nitrate flux positively influencing aquatic plant cover as well as water quality and thus negatively fish species richness, the surrounding area covered by row crops is essentially connected to fish distribution patterns (Strayer et al., 2003). The Danube River Basin has already experienced significant changes in water quality including chemical alterations due to nitrate and other nutrient pollutants from agriculture and various land use factors (Chapman et al., 2016), which are known to favour algal blooms. Further decreases of oxygen concentrations resulting from water quality degradation are expected, which can drastically influence fish species and their ability to cope with warming (Chapman et al., 2016;Verberk et al., 2016). ...
... The Danube River Basin has already experienced significant changes in water quality including chemical alterations due to nitrate and other nutrient pollutants from agriculture and various land use factors (Chapman et al., 2016), which are known to favour algal blooms. Further decreases of oxygen concentrations resulting from water quality degradation are expected, which can drastically influence fish species and their ability to cope with warming (Chapman et al., 2016;Verberk et al., 2016). Especially gravel-spawning riverine fish species are affected by intensely used cropland. ...
Article
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Niche-based species distribution models (SDMs) play a central role in studying species response to environmental change. Effective management and conservation plans for freshwater ecosystems require SDMs that accommodate hierarchical catchment ordering and provide clarity on the performance of such models across multiple scales. The scale-dependence components considered here are: (a) environment spatial structure, represented by hierarchical catchment ordering following the Strahler system; (b) analysis grain, that included 1st to 5th order catchments; and (c) response grain, the grain at which species respond most, represented by local and upstream catchment area effects. We used fish occurrence data from the Danube River Basin and various factors representing climate, land cover and anthropogenic pressures. Our results indicate that the choice of response grain – local vs. upstream area effects – and the choice of analysis grain, only marginally influence the performance of SDMs. Upstream effects tend to better predict fish distributions than corresponding local effects for anthropogenic and land cover factors, in particular for species sensitive to pollution. Key predictors and their relative importance are scale and species dependent. Consequently, choosing proper species dependent spatial scales and factors is imperative for effective river rehabilitation measures.
... Therefore, the impact prediction models must be unique for each aquatic ecosystem. Studies [60,61] which analyzed the climate change effect on the Danube-Danube Delta-Black Sea macrosystem reported an upward trend for eutrophication within the Danube River Basin, with urban settlement and agriculture contributing majorly to amplifying the nitrogen and phosphorus emissions, respectively [61]. The monitoring of aquatic macrosystem water quality is essential for developing a BE and indicates trends over time, which offers the possibility of identifying the sustainability of a BE and selecting the most appropriate direct remedial actions. ...
... Therefore, the impact prediction models must be unique for each aquatic ecosystem. Studies [60,61] which analyzed the climate change effect on the Danube-Danube Delta-Black Sea macrosystem reported an upward trend for eutrophication within the Danube River Basin, with urban settlement and agriculture contributing majorly to amplifying the nitrogen and phosphorus emissions, respectively [61]. The monitoring of aquatic macrosystem water quality is essential for developing a BE and indicates trends over time, which offers the possibility of identifying the sustainability of a BE and selecting the most appropriate direct remedial actions. ...
Article
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European Union (EU) policy encourages the development of a blue economy (BE) by unlocking the full economic potential of oceans, seas, lakes, rivers and other water resources, especially in member countries in which it represents a low contribution to the national economy (under 1%). However, climate change represents a main barrier to fully realizing a BE. Enabling conditions that will support the sustainable development of a BE and increase its climate resiliency must be promoted. Romania has high potential to contribute to the development of the EU BE due to its geographic characteristics, namely the presence of the Danube Delta-Black Sea macrosystem, which is part of the Romanian Lower Danube Euroregion (RLDE). Aquatic living resources represent a sector which can significantly contribute to the growth of the BE in the RLDE, a situation which imposes restrictions for both halting biodiversity loss and maintaining the proper conditions to maximize the benefits of the existing macrosystem. It is known that climate change causes water quality problems , accentuates water level fluctuations and loss of biodiversity and induces the destruction of habitats, which eventually leads to fish stock depletion. This paper aims to develop an analytical framework based on multiple linear predictive and forecast models that offers cost-efficient tools for the monitoring and control of water quality, fish stock dynamics and biodiversity in order to strengthen the resilience and adaptive capacity of the BE of the RLDE in the context of climate change. The following water-dependent variables were considered: total nitrogen (TN); total phosphorus (TP); dissolved oxygen (DO); pH; water temperature (wt); and water level, all of which were measured based on a series of 26 physicochemical indicators associated with 4 sampling areas within the RLDE (Brăila, Galați, Tulcea and Sulina counties). Predictive models based on fish species catches associated with the Galati County Danube River Basin segment and the ʺDanube Delta" Biosphere Reserve Administration territory were included in the analytical framework to establish an efficient tool for monitoring fish stock dynamics and structures as well as identify methods of controlling fish biodiversity in the RLDE to enhance the sustainable development and resilience of the already-existing BE and its expansion (blue growth) in the context of aquatic environment climate variation. The study area reflects the integrated approach of the emerging BE, focused on the ocean, seas, lakes and rivers according to the United Nations Agenda. The results emphasized the vulnerability of the RLDE to climate change, a situation revealed by the water level, air temperature and water quality parameter trend lines and forecast models. Considering the sampling design applied within the RLDE, it can be stated that the Tulcea county Danube sector was less affected by Citation: Petrea, S.M.; Zamfir, C.; Simionov, I.A.; Mogodan, A.; Nuţă, F.M.; Rahoveanu, A.T.; Nancu, D.; Cristea, D.S.; Buhociu, F.M. A Forecasting and Prediction Methodology for Improving the Blue Economy Resilience to Climate Change in Romanian Lower Danube Euroregion. Licensee MDPI, Basel, Switzer-land. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecom-mons.org/licenses/by/4.0/). Sustainability 2021, 13, 11563 2 of 30 climate change compared with the Galați county sector as confirmed by water TN and TP forecast analysis, which revealed higher increasing trends in Galați compared with Tulcea. The fish stock biodiversity was proven to be affected by global warming within the RLDE, since peaceful species had a higher upward trend compared with predatory species. Water level and air temperature forecasting analysis proved to be an important tool for climate change monitoring in the study area. The resulting analytical framework confirmed that time series methods could be used together with machine learning prediction methods to highlight their synergetic abilities for monitoring and predicting the impact of climate change on the marine living resources of the BE sector within the RLDE. The forecasting models developed in the present study were meant to be used as methods of revealing future information, making it possible for decision makers to adopt proper management solutions to prevent or limit the negative impacts of climate change on the BE. Through the identified independent variables, prediction models offer a solution for managing the dependent variables and the possibility of performing less cost-demanding aquatic environment monitoring activities.
... Criticism of the WFD has been in several areas; these include its overly ambitious timelines (Hering et al., 2010;Liefferink et al., 2011;Voulvoulis et al., 2017), the challenges of coordinating assessment methods and monitoring arrangements (Hering et al., 2010;Nielsen et al., 2013;Chapman et al., 2016), the effectiveness of public participation and stakeholder involvement Koontz and Newig, 2014), and its accounting of the complexities of cross-sectoral integration (Pahl-Wostl et al., 2012;Green et al., 2013;Jager et al., 2016). ...
Article
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Scales and boundaries are integral components of environmental governance policies. These scales and boundaries – administrative, political or institutional – usually do not align with biophysical scales. For effective environmental governance, a key policy question is which scale to use when. This question, however, is often ignored due to the unavailability of the tools and data necessary for incorporating scale issues into policy design and implementation. In this paper, we introduce the concept of scale–descale–rescale (SDR) as a tool for policy analysis. 'scale' refers to the current scale of a policy; 'descale' refers to levels of scale that are higher and lower than the current scale; 'rescale' refers to the process of bringing all three scales together in order to examine their interactive impact. In this paper, we present an examination of the framing and implementation of the EU Water Framework Directive (WFD) in the Danube River Basin; we find that the current scale of the WFD design is at the river basin level while, at the same time, its implementation is expected to be carried out at the national and subriver basin levels. To fully understand the efficacy of the WFD as a policy instrument, we first use the SDR tool to descale the design and implementation of the WFD at five scales: multinational, national, subnational, river basin and sub-river basin; we then rescale them in order to observe the overall impact. We find that in the Danube River Basin an interconnected web of scale issues is impacting and often obstructing effective implementation of the WFD
... As reported by Chapman et al. (2016), computational methodologies that specifically focus on sampling frequency (seasonal and spatial) can help in optimizing the monitoring design, avoiding significant information loss. For example, in river monitoring, it is generally accepted that sampling points should be located at the mouth of the main tributaries. ...
Conference Paper
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Kalamas aquatic ecosystem, including Lake Pamvotis and Lapsista trench, concerns two regional units, those of Ioannina and Thesprotia. Because of the intense human activity near its banks, the river seems particularly lumbered. In order to be able to cope with this situation, we must identify the environmental pressures it receives and monitor the quality of its waters, as a first step in taking de-pollution measures. In the present study, an attempt is made, through existing surveys, to determine the critical monitoring points on its flow, the required frequency of sampling, as well as the necessary technological infrastructure for the creation of time series of measurements and its cost. Finally, a package of policy measures for inter-municipal cooperation and citizens' involvement in the respective decisions is proposed.
... The release of pesticides, as a result of agricultural activities can cause freshwater, groundwater and marine water pollution through drainage, leaching, runoff and surface deposition (Radović et al., 2015;Chapman et al., 2016). Water insoluble substances tend to bound to particulate and organic matters and to settle in the sediment. ...
Article
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We apply a tracer model linked with a 3D circulation model to simulate transport and fate of water-soluble persistent substances in the Black Sea that do not bioaccumulate to a considerable extent. The model uses specified degradation time and identical concentrations in the rivers to build a correlation between average concentration in the basin and half-life (DT50). The average concentration in certain sub-regions of the Black Sea can be estimated using an exponential dependence of DT50, if DT50 and concentration in rivers are known. Averaging is performed on the simulations from 2000 to 2019 with real atmospheric forcing and river runoff. A well-defined seasonal cycle is evident for the average shelf concentration, while the average concentration in the deep region does not show a pronounced seasonal cycle or inter-annual variations. With the help of the existing observational data, we estimate DT50 and concentration in the rivers for carbamazepine, sulfamethoxazole and terbuthylazine. Atrazine and simazine are believed to have accumulated in the basin for a long time due to their widespread use in the past and the slow rate of degradation in the marine environment.
... However, these methods are not widely known and elaborated yet [10,11]. On the other hand, monitoring of large rivers is in some cases excessive [12][13][14]. ...
Article
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Watershed area and a bunch of relief, land use, and wastewater characteristics for 32 upland and 33 lowland small river courses are generated. Based on these characteristics, logistic binary regression models are trained to predict if the river achieves the good physico-chemical status, and discriminant analysis models are trained to predict the physico-chemical status class on a five-class scale. Univariate models revealed that elevation (for upland rivers), the share of artificial surfaces (for lowland rivers) along with forests, and wastewater quality variables such as biochemical oxygen demand, chemical oxygen demand, and phosphorus are the most significant predictors. Discriminant analysis models performed better on upland than on lowland rivers. Achievement of good status could be predicted with an accuracy of ~90% (with 2 to 4 variable logit models), whereas the status class with an accuracy of 63/48% (with 2 to 4 variable discriminant analysis models) for upland and lowland rivers, respectively. This contribution uses Hungary as a case study.
... The effective monitoring of water quality parameters has a profound impact on the overall quality of a catchment area (Chapman et al., 2016). A number of aquatic systems and organisms are dependent on the quality of the water for survival (Bilotta and Brazier, 2008;Amoatey and Baawain, 2019). ...
Article
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Due to the growing threat of climate change, new advances in water quality monitoring strategies are needed now more than ever. Reliable and robust monitoring practices can be used to improve and better understand catchment processes affecting the water quality. In recent years the deployment of long term in-situ sensors has increased the temporal and spatial data being obtained. Furthermore, the development and research into remote sensing using satellite and aerial imagery has been incrementally integrated into catchments for monitoring areas that previously might have been impossible to monitor, producing high-resolution data that has become imperative to catchment monitoring. The use of modelling in catchments has become relevant as it enables the prediction of events before they occur so that strategic plans can be put in place to deal with or prevent certain threats. This review highlights the monitoring approaches employed in catchments currently and examines the potential for integration of these methods. A framework might incorporate all monitoring strategies to obtain more information about a catchment and its water quality. The future of monitoring will involve satellite, in-situ and air borne devices with data analytics playing a key role in providing decision support tools. The review provides examples of successful use of individual technologies, some combined approaches and identifies gaps that should be filled to achieve an ideal catchment observation system.
... El agua, como parte de un ecosistema dinámico en el que interactúan recursos naturales y seres vivos, es indispensable para la vida, el bienestar de las personas y el desarrollo de las sociedades [2]. El principio fundamental que define el agua como un derecho humano obliga a las naciones a realizar esfuerzos para que los pobladores cuenten con un recurso de calidad y en cantidad necesaria para satisfacer sus necesidades [3]. ...
Article
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The present work was developed between 2015 and 2018 in the community of Corral de Piedra, Nicoya, Guanacaste. In this area there are two seasons: dry and rainy; however, drastic climate change has led to extreme changes in rainfall patterns and strong periods of drought. In this study, the quality of communal drinking water was assessed, determining it depicts high compliance with decree 38924-S in terms of physicochemical and microbiological parameters. According to Mora-Alvarado et al [1] wells and springs’ water quality criteria, the results obtained from analysis of most sampling sites in the community of Corral de Piedra showed excellent quality conditions. A hydrogeochemical characterization of the water extracted from the well was carried out using the Piper diagram, resulting in bicarbonated - calcium type water. The application of the Kendall correlation matrix yielded 25 significant correlations, pH - nitrate and conductivity - bicarbonate being the ones with the highest correlation. Finally, the focal components analysis was performed and it showed that 5 main components explained the data variance in a significant way (85,6%).
... Many parts of the water quality monitoring system have been subjected to optimization by means of advanced statistical methods: the two largest rivers: Danube (e.g. Chapman et al. 2016) and Tisza (e.g. Tanos et al. 2011Tanos et al. , 2015, Lake Balaton (e.g. ...
Article
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With the introduction of the Water Framework Directive, the relative importance of smaller waterways increased. This statement is particularly true for Hungary, where water-quality monitoring of most smaller rivers only began 12 years ago. Due to their large number, and the lack of historical data concerning their state, systematic monitoring is a challenge. In the current study, 101 creeks are characterized on the one hand by 13 physico-chemical quality parameters (pH, electric conductivity, chloride ion concentration, dissolved oxygen, oxygen saturation, biochemical oxygen demand, chemical oxygen demand, total organic carbon, ammonium nitrogen, total inorganic nitrogen, total nitrogen, orthophosphate and total phosphorus), on the other hand by their watershed's relief, land use, and point sources' pollution indicators. Euclidean distance between water bodies (henceforth WBs) is calculated according to normalized physico-chemical monitoring values. They are grouped into clusters using the hierarchical clustering method. Watershed characteristics are used to explain the clustering via linear discriminant analysis. The investigation revealed that the main driver of cluster group creation is related to human impact: diffuse agricultural and point-source pollution. The first of the three clusters involved water bodies with low or no human impact; the second cluster contained those with medium-level anthropogenic disturbance, while waters with high pollution values formed the third cluster. Mean distance between heavily polluted waters was 1.5 times higher than that between those showing no or low disturbance, meaning that pristine waters are more similar to one another than polluted ones. The current number of samples per river is twice as high in cluster 1 as in cluster 3, revealing that there is room for optimization of the monitoring system. This contribution uses Hungary as a case study.
... Therefore, water quality monitoring has been the subject of many scientific studies (Kerachian & Karamouz 2007;Rehana & Mujumdar 2009;Louzadavalory et al. 2016;Meng et al. 2017). Water quality modeling is an important tool, helping optimize the management of the water resources (Mesbah et al. 2009;Jiang et al. 2013;Chapman et al. 2016). In the recent decades, many water quality models have been developed to simulate river water quality. ...
Article
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River water quality assessment, affected by pollution load, and river regime changes in various climate conditions, is an implementation that simplifies water resources management, and justifies terms for increases or decreases in human activities. The current paper aims to offer a water quality model of a river considering parametric, hydrologic, and pollution load uncertainty by using uncertainty indexes like Plevel, ARIL, and NUE. These indexes were used to analyze the influences of the model's parameters and the river's regime alternations on the results. A Qual2K model, calibrated with PSO algorithm, is presented and connected to GLUE algorithm to assess the model's uncertainties like effective input parameters on the modeled variations, headwater flow, and input pollutions. Zarjoob River, in the north of Iran, was chosen as the case study. The results illustrate that the interaction among parameters, hydrologic and pollutant discharge data should be considered in river water quality simulation. The presented methodology can analyze the influences of parametric uncertainty, parametric and hydrologic uncertainty, and pollution input load uncertainty according to any quantity of observations and the modeled results of any river. HIGHLIGHTS Using PSO algorithm in order to calibrate a Qual-2K model.; Assessment of parametric and hydrologic uncertainty in the meantime.; Using scenarios for input load uncertainty assessment.; Assessment of parametric uncertainty-hydrological uncertainty-point sources load uncertainty.; Presenting a framework applicable in uncertainty evaluation of any river water quality model.;
... As such, multiple modelling approaches have been applied to simulate the behaviours of monitoring networks over time and space. The most direct approach to reviewing/ revising the monitoring plan is variogram modelling (Kriging), which is capable of estimating the limits of suitable sampling points and frequency within time and space separately, based on the fact that the samples are conveniently independent (Chapman et al., 2016). ...
Article
The evaluation of the importance of having accurate and representative stations in a network for river water quality monitoring is always a matter of concern. The minimal budget and time demands of water quality monitoring programme may appear very attractive, especially when dealing with large-scale river watersheds. This article proposes an improved methodology for optimising water quality monitoring network for present and forthcoming monitoring of water quality under a case study of the Selangor River watershed in Malaysia, where different monitoring networks are being used by water management authorities. Knowing that the lack of financial resources in developing countries like Malaysia is one of the reasons for inadequate monitoring network density, to identify an optimised network for cost-efficiency benefits in this study, a geo-statistical technique coupled Kendall's W was first applied to analyse the performance of each monitoring station in the existing networks under the monitored water quality parameters. Second, the present and future changes in non-point pollution sources were simulated using the integrated Cellular Automata and Markov chain model (CA–Markov). Third, Station Potential Pollution Score (SPPS) determined based on Analytic Hierarchy Process (AHP) was used to weight each station under the changes of non-point pollution sources for 2015, 2024, and 2033 prior to prioritisation. Finally, according to the Kendall's W test on kriging results, the weights of non-point sources from the AHP evaluation and fuzzy membership functions, six most efficient sampling stations were identified to build a robust network for the present and future monitoring of water quality status in the Selangor River watershed. This study proposes a useful approach to the pertinent agencies and management authority concerned to establish appropriate methods for developing an efficient water quality monitoring network for tropical rivers.
... Large watersheds pose many challenges for monitoring and management of water quality, particularly in multinational basins where legislative frameworks and priorities for water resources management may differ (Bloesch et al., 2012). But whether in a local or global context, to contribute to a river basin management, it is necessary to align the monitoring activities with the following (Chapman et al., 2016): 1) identify trends over time; 2) get a full understanding of the activities impacts and their interactions in the watershed; 3) identify the impacts of downstream; and 4) most appropriate direct corrective measures. In addition, the objective of monitoring water quality is to acquire measurable information on the chemical, physical, and biological parameters of water using statistical sampling methods (Sanders et al., 1983). ...
Article
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Rapid development and population growth have resulted in an ever-increasing level of water pollution in Malaysia. Therefore, this study was conducted to assess water quality of Selangor River in Malaysia. The data collected under the river water quality monitoring program by the Department of environment from 2005 to 2015 were used for statistical analyses. The local water quality indices were computed and a trend detection technique and cluster analysis were applied, respectively, to detect changes and spatial disparity in water quality trends. The results showed that the river water is of good quality at all stations, with the exception of 1SR01 and 1SR09 located upstream, which recorded moderate water quality indices of 68 and 71, respectively. The results of trend analysis showed downward trends in dissolved oxygen, biochemical oxygen demand and ammonia nitrogen, for most water quality stations, as well as increasing trends in chemical oxygen, suspended solids, pH and temperature for most stations. In addition, the results of cluster and time series analyses showed that the trend variation in dissolved oxygen, pH, and temperature between the station clusters is relatively low as compared to chemical oxygen demand, biochemical oxygen demand, suspended solids, and ammonia nitrogen. With the peak concentration of 13 mg/L for dissolved oxygen observed in cluster 2 in 2014, and the highest decrease in suspended solids (8 mg/L) observed in cluster 1 for 2015. This finding demonstrates that these combined statistical analyses can be a useful approach for assessing water quality for adequate management of water resources.
... These river basins encompass a broad geographic diversity including variation in environmental and water conditions, history, economics, and political features. These IRBOs are recognized as leaders in transboundary river governance and have been actively generating scientific knowledge (e.g., Chapman et al., 2016;Clamen and Macfarlane, 2015;Houba et al., 2013). As such, they provide an ideal starting point for examining the production and use of science in transboundary river basins. ...
Article
As key venues for interaction and cooperation, international river basin organizations (IRBOs) are significant contributors to hydrodiplomacy in transboundary river basins. As part of their efforts to support hydrodiplomacy, IRBOs engage in the production and use of science. The manner in which that science is produced, and how it contributes to hydrodiplomacy, is not well understood. This paper examines the production and use of science by three IRBOs: the (US – Canada) International Joint Commission, the International Commission for the Protection of the Danube River, and the Mekong River Commission. We find the science produced by the IRBOs to support hydrodiplomacy extends beyond measuring and monitoring to include more advanced and analytical forms of science. In producing science, we observe that the IRBOs balance considerations of capacity, ownership, and how the politics of the basin will influence the production and use of the science. Given the challenge of balancing across these considerations, future research is needed to determine what mechanisms and processes for producing science can best facilitate its use in hydrodiplomacy.
... The Danube River, with a length of 2857 km (of which 1076 km in Romania) and a multiannual average flow rate of 6460 m 3 /s at the entrance in the Danube Delta, is the second largest river in Europe (after the Volga) (ICPDR 2019; Paun et al. 2017). The Danube River Basin, with a total area of approximately 800,000 km 2 , is an emissary to the Black Sea and a collector of all discharges from upstream riparian countries where water is collected from the territories of 10 countries, being considered to be the most international river basin in the world (Chapman et al. 2016). More than 80 million people live in this basin, many of them depending on the Danube for potable water, energy production, agriculture and transport. ...
Article
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Water is an important receptor of environmental problems generated by anthropogenic activities, the water quality being affected by their magnitude and impact as well as by climate change. Given the international and cross-border nature of the Danube River and being aware that the pollution risk assessment is one of the key elements of the ecology and health of the people in its region, this paper assessed the state of water quality in the Lower Danube River in accordance with Water Framework Directive (Directive 2000/60/EC). The intensive monitoring program applied by the National Institute for Research and Development in Environmental Protection (INCDPM) took place during the period 2011–2017, in which approximately 1500 samples were taken and processed from 10 monitoring sites and the quality indicators stipulated in M.O. 161/2006 were analysed according to the standards in force. In this monitoring area (km 375–km 175), hydrotechnical works have been done in order to improve navigation conditions. Therefore, on the basis of the data obtained from the monitoring campaigns, multivariate statistical methods of water quality assessment were applied on the complex set of data, and at the same time, the multiparametric quality index (ICPM) was applied, an index of global comparative assessment of water quality over historical trends, developed by INCDPM. Following the evaluation of the results, the water quality in the Lower Danube River was characterized as moderately polluted and corresponds to Class III of surface water quality. The ecosystem approach indicates that the values of the monitored indicators did not correspond to the target values according to the Water Framework Directive.
... Large watersheds pose many challenges for monitoring and management of water quality, particularly in multinational basins where legislative frameworks and priorities for water resources management may differ (Bloesch et al., 2012). But whether in a local or global context, to contribute to a river basin management, it is necessary to align the monitoring activities with the following (Chapman et al., 2016): 1) identify trends over time; 2) get a full understanding of the activities impacts and their interactions in the watershed; 3) identify the impacts of downstream; and 4) most appropriate direct corrective measures. In addition, the objective of monitoring water quality is to acquire measurable information on the chemical, physical, and biological parameters of water using statistical sampling methods (Sanders et al., 1983). ...
Article
Rapid development and population growth have resulted in an ever-increasing level of water pollution in Malaysia. Therefore, this study was conducted to assess water quality of Selangor River in Malaysia. The data collected under the river water quality monitoring program by the Department of environment from 2005 to 2015 were used for statistical analyses. The local water quality indices were computed and a trend detection technique and cluster analysis were applied, respectively, to detect changes and spatial disparity in water quality trends. The results showed that the river water is of good quality at all stations, with the exception of 1SR01 and 1SR09 located upstream, which recorded moderate water quality indices of 68 and 71, respectively. The results of trend analysis showed downward trends in dissolved oxygen, biochemical oxygen demand and ammonia nitrogen, for most water quality stations, as well as increasing trends in chemical oxygen, suspended solids, pH and temperature for most stations. In addition, the results of cluster and time series analyses showed that the trend variation in dissolved oxygen, pH, and temperature between the station clusters is relatively low as compared to chemical oxygen demand, biochemical oxygen demand, suspended solids, and ammonia nitrogen. With the peak concentration of 13 mg/L for dissolved oxygen observed in cluster 2 in 2014, and the highest decrease in suspended solids (8 mg/L) observed in cluster 1 for 2015. This finding demonstrates that these combined statistical analyses can be a useful approach for assessing water quality for adequate management of water resources. © 2020 GJESM.
... In this regard, comprehensive water quality assessment has become an important tool to develop and implement strategies to safeguard freshwater ecosystems (Grizzetti et al., 2017). The use of multiple lines of evidences (LOEs) has been widely recommended to assess water quality, as this integrative method gives a wider picture of freshwater ecosystem health that otherwise could not be done by isolated approaches Backhaus et al., 2019;Buchwalter et al., 2017;Chapman et al., 2016;Merrington et al., 2014;Palma et al., 2018;Reyjol et al., 2014). For instance, physicochemical endpoints provide information on concentrations of chemical stressors in the aquatic ecosystem, but they do not describe how biological communities are affected by them Serpa et al., 2014). ...
Article
Degradation of freshwater ecosystems by uncontrolled human activities is a growing concern in the tropics. In this regard, we aimed at testing an integrative framework based on the IFEQ index to assess freshwater ecosystem health of river basins impacted by intense livestock and agricultural activities, using the Muchacho River Basin (MRB) as a case study. The IFEQ combines multiple lines of evidence such as riverine hydromorphological analysis (LOE 1), physicochemical characterization using ions and pesticides (LOE 2), aquatic macroinvertebrate monitoring (LOE 3), and phytotoxicological essays with L. sativa (LOE 4). Overall, results showed an important reduction in streamflow and an elevated increase in ion concentrations along the MRB caused by deforestation and erosion linked to agricultural and livestock activities. Impacts of the high ion concentrations were evidenced in macroinvertebrate communities as pollution-tolerant families, associated with high conductivity levels, represented 92 % of the total abundance. Pollution produced by organophosphate pesticides (OPP) was critical in the whole MRB, showing levels that exceeded 270-fold maximum threshold for malathion and 30-fold for parathion, the latter banned in Ecuador. OPP concentrations were related to low germination percentages of L. sativa in sediment phytotoxicity tests. The IEFQ index ranged from 44.4 to 25.6, indicating that freshwater ecosystem conditions were “bad” at the headwaters of the MRB and “critical” along the lowest reaches. Our results show strong evidence that intense agricultural and livestock activities generated significant impacts on the aquatic ecosystem of the MRB. This integrative approach better explains the cumulative effects of human impacts, and should be replicated in other basins with similar conditions to help decision-makers and concerned inhabitants generate adequate policies and strategies to mitigate the degradation of freshwater ecosystems.
... Some members of these pharmaceutically active compounds (PhACs) have been found in concentrations up to the μg/L level in sewage influent and effluent samples as well as in surface waters located downstream of municipal sewage treatment plants (STPs), due to their persistence and incomplete elimination within STPs [9,10]. River investigations also revealed the occurrence of numerous pharmaceuticals including metamizole and antipyrine/ derivatives up to a μg/L range [11][12][13][14][15][16]. PhACs can reach the environment via numerous possibilities, of which the most common ways are the discharge of sewage, direct excretion or the distribution via agricultural biosolids and soil amendment [17][18][19][20][21][22][23]. ...
Article
In this work, a set of ion-selective electrodes for the detection of antipyrine and some of its structurally closely related derivatives is developed. These novel potentiometric sensors rely on metallocarborane, cobalt bis(dicarbollide) anion ([3,3’-Co(1,2-C2B9H11)2]⁻) complexes with the protonated antipyrine derivative as active recognition element. All complexes were characterized, embedded in a PVC membrane, and coated on top of commercial and self-fabricated electrodes. All systems were in-depth evaluated and optimized with focus on their analytical performance, leading to a set of electrodes for antipyrine, 4-aminoantipyrine and 4-(acetamido)antipyrine, which showed a near Nernstian slope (55 to 57 mV/dec) in the range of 10⁻⁵ to 10⁻² mol/L and a limit of detection in the μM range. To lower the detection limit and to enable environmental stream water pollution monitoring, we implemented a solid-phase extraction step which could be used to achieve a pre-concentration of a factor >300 (recovery rates: 81-84%) and to lower the detection limit from the μM to the nM range. The combination of our new and highly selective electrodes with this SPE step enables the possibility to monitor antipyrine derivatives simultaneously in either an environmental surrounding or in pharmaceutical formulations. The combination of metallocarborane based ISEs with an SPE pre-concentration step and the in-depth evaluation of the closely related derivatives finally provides a set of valuable tools as well as new insights into their selectivity and real-life applicability.
... It is an urgent and difficult task to build a safe water environment, for which water quality monitoring is one of the most significant foundations [8]. Traditional water quality monitoring is mainly based on field sampling, which is costly and time-consuming, and the data obtained are discontinuous [9], which cannot meet the current requirements for large-scale and real-time water body monitoring [10]. As for this point, remote sensing technology has provided a new direction for water quality monitoring by its powerful advantages [11]. ...
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Some essential water conservation areas in China have continuously suffered from various serious problems such as water pollution and water quality deterioration in recent decades and thus called for real-time water pollution monitoring system underwater resources management. On the basis of the remote sensing data and ground monitoring data, this study firstly constructed a more accurate retrieval model for total phosphorus (TP) concentration by comparing 12 machine learning algorithms, including support vector machine (SVM), artificial neural network (ANN), Bayesian ridge regression (BRR), lasso regression (Lasso), elastic net (EN), linear regression (LR), decision tree regressor (DTR), K neighbor regressor (KNR), random forest regressor (RFR), extra trees regressor (ETR), AdaBoost regressor (ABR) and gradient boosting regressor (GBR). Then, this study applied the constructed retrieval model to explore the spatial-temporal evolution of the Miyun Reservoir and finally assessed the water quality. The results showed that the model of TP concentration built by the ETR algorithm had the best accuracy, with the coefficient R2 reaching over 85% and the mean absolute error lower than 0.000433. The TP concentration in Miyun Reservoir was between 0.0380 and 0.1298 mg/L, and there was relatively significant spatial and temporal heterogeneity. It changed remarkably during the periods of the flood season, winter tillage, planting, and regreening, and it was lower in summer than in other seasons. Moreover, the TP in the southwest part of the reservoir was generally lower than in the northeast, as there was less human activities interference. According to the Environmental Quality Standard for the surface water environment, the water quality of Miyun Reservoir was overall safe, except only for an over-standard case occurrence in the spring and September. These conclusions can provide a significant scientific reference for water quality monitoring and management in Miyun Reservoir.
... Chapman D V's team explored current water quality issues in the Danube basin and evaluated water quality monitoring methods in the context of providing information for watershed management plans. It provides new insights into the causes and impacts of water quality changes in other large international river basins (Chapman et al. 2016). Karim h and other scholars used flow cytometry to monitor water pollution and disinfection treatment efficiency of bacterial cells, and found that flow cytometry was more accurate than conventional methods in detecting cell activity, and it was an accurate and rapid method for monitoring water pollution and bactericide treatment efficiency of cooling tower (Karim et al. 2018). ...
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In many sea areas, toxic and harmful chemicals vastly exceed the standard, which not only has had a very bad impact on the survival of marine organisms, but also damages the safety of edible groundwater. With the continuous development of artificial intelligence and deep learning, the most efficient and safe method to detect seawater is with unmanned ship. By processing and fusing the images transmitted by the two radars, the common advantages of the two sensors are integrated, and the comprehensiveness of the unmanned aerial vehicle's (UAV;s) perception of the surrounding environment is improved. In order to improve the accuracy and safety of UAV offshore operations, this study designed an electric propulsion unmanned ship and its automatic control system according to the requirements of water quality sampling. Based on the small body theory, the model of an unmanned ship with the least resistance and the best safety is designed. According to the requirements of water quality sampling in sea areas, the vessel was equipped with collection and analysis systems to measure six elements of water quality. The Realizable k-e turbulence model was used to simulate the self-recovery ability of an unmanned ship under wave disturbance. Theoretically, the unmanned ship can achieve self-righting in 4.25 s. For actual navigation, the unmanned ship can effectively avoid obstacles, and the basic information on seawater quality was within the specified range. The unmanned ship constructed in this study can be used as an auxiliary tool for water quality detection. Compared with various study methods, the proposed method obtained a better performance. HIGHLIGHTS Electric propulsion; Unmanned ship; Water quality monitoring; Automatic sampling; Seawater;
... However, gradual steps can be taken to move the wheel of growth through citizen science, as shown in Sect. 5 . Water quality monitoring of the Lower Danube River by citizen scientists cannot replace traditional monitoring strategies made by professional scientists, such as the Trans National Monitoring Network or the Joint Danube Survey [ 21 ], but if a citizen science program is initiated and executed under close professional supervision, in terms of accuracy, quality control and spatial and temporal resolution, the resulting data may complement traditional records. ...
Chapter
Human changes on the Danube River have transformed it into a heavily engineered river, severely threatening its ecological status. The status and management strategies vary significantly between regions of the Danube River Basin. Citizen science approach can be the bridge in harmonizing water management practices across the Danube Basin and in recording large water quality datasets. This chapter reviews citizen science actions in the Lower Danube Basin and the available tools for citizens in this region. The study has shown that the activities with public involvement in this region have been supported by non-governmental organizations (NGOs) or independent citizen science platforms. Citizen science activities in this region are scarce and infrequent, and most of them without supervision from professional researchers or involvement from local authorities. Limited access to funds, lack of trust between participating groups and the restricted power of communities to voice concerns have been found as factors influencing citizen science activities. The scientists may be the missing link between policy makers, water managers and citizens, while providing the optimal tools and knowledge to all sectors. Professional scientists can collaborate with NGOs and build upon their extensive expertise and success in engaging with citizens and authorities.
... As well, the Water Framework Directive [4] appeals all rivers, lakes, transitional and coastal waters of the European Union to be in good ecological status in the near future. From this perspective, adequate monitoring, surveillance, management, and maintenance programs must be accomplished constantly to acquire reliable instruments for a better insight into aquatic ecosystems [5]. Lakes are complex ecosystems, comprising distinct habitats which are sustained of several in-lake processes (biological, physical and chemical). ...
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This study aimed to assess the water quality of certain lakes (Bogdaproste, Trei Ozere and Radacinos) belonging to the Danube Delta, Romania. Deltaic ecosystems are subject to natural and man-made environmental stressors. If in the past these ecosystems were largely threatened by eutrophication and organic/inorganic pollution, nowadays, we must focus on hydro morphological impact. This refers to the physical character and water content of the aquatic environment, impoundment (dams and flood gate), channelization and embankments, as well as clog/siltation of lakes. Environmental parameters are those physical, chemical and biological indicators used to characterize a freshwater body, and, which vary in time and space. In this regard, 44 water samples were collected in the dry season from the three lakes, for analysis of physical-chemical quality indicators. A series of physical (T, EC, TDS, turbidity, TSS, transparency) and chemical parameters (pH, DO, nutrients, SiO2, TOC, SO42-, ORP, technophilic elements) were considered. The results obtained in the physical-chemical analyses revealed that the majority of parameters were found in line with enforcing environmental regulations. Despite that, P-PO43- and Cd concentration results of some samples were found above certain permissible limits set by the normative. Probably, these inadvertences can be associated with local conditions of the transitional deltaic environment. Further analysis is required conducting repeated measurements with the same question, meaning a routine monitoring, especially P-PO43- and Cd. Finally, it was concluded that the results of this study showed a good quality of water in investigated lakes that did not pose potential health and environmental problems related to the biota.
... Branched river systems drain areas with different land-use types, each of which brings different sets of metals and pollutants which affect the quality of surface runoff and river water [59][60][61]. Effective river water quality management requires information on the influence of all types of anthropogenic impacts within the particular watersheds (urban and rural) throughout the river basin [62][63][64]. When many factors need to be considered, the solution to these complex problems is most promising when using combined cluster and discriminant analysis, and others [65,66]. ...
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The quantitative and qualitative depletion of water resources (both surface and groundwater) is closely related to the need to protect soils against degradation, rationalization of land use, and regulation of surface water runoff within the watershed area. Belgorod Oblast (27,100 km2), one of the administrative regions of European Russia, was chosen as the study area. It is characterized by a high activity of soil erosion (the share of eroded soils is about 48% of the total area of arable land). The development phase of the River Basin Environmental Management Projects (217 river basins from the fourth to seventh order) allowed for the proceeding of the development of an integrated monitoring system for river systems and river basin systems. The methods used to establish a geoecological network for regional monitoring include the selection and application of GIS techniques to quantify the main indicators of ecological state and predisposition of river basins to soil erosion (the share of cropland and forestland, the share of the south-oriented slopes, soil erodibility, Slope Length and Steepness (LS) factor, erosion index of precipitation, and the river network density) and the method of a hierarchical classification of cluster analysis for the grouping of river basins. An approach considering the typology of river basins is also used to expand the regional network of hydrological gauging stations to rationalize the national hydrological monitoring network. By establishing 16 additional gauging stations on rivers from the fourth to seventh order, this approach allows for an increase in the area of hydro-agroecological monitoring by 1.26 times (i.e., up to 77.5% of the total area of Belgorod Oblast). Some integrated indicators of agroecological (on the watershed surface) and hydroecological (in river water flow) monitoring are proposed to improve basin environmental management projects. Six-year monitoring showed the effectiveness of water quality control measures on an example of a decrease in the concentrations of five major pollutants in river waters.
... Basic physico-chemical parameters such as conductivity of water, dissolved oxygen level, pH, and water temperature were kept essentially consistent during the time of exposure following the standard parameters of Bhatnagar & Devi, (2013) and Chapman et al., (2016). As the trials progressed, the temperature dropped from 30°C to 21°C. ...
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Chlorpyrifos is a widely applied insecticide that permeates on most waterways and affects aquatic organisms. The growth performances, hematological and histological impacts on Nile tilapia, Oreochromis niloticus following a 60 day of exposure to varying concentrations of chlorpyrifos 20 EC (T1 08 µgL-1, T2 16 µgL-1, and T3 32 µgL-1) were compared to a control Tc 0 µgL-1. The 96-hour LC50 of chlorpyrifos 20 EC was calculated as 46.80 μgL-1. The water quality parameters were recorded regularly. The value of dissolved O2 and NH3 stayed rather steady, although temperature varied considerably. It was revealed that as chlorpyrifos levels go up, the percentage of weight gain (WG %), specific growth rates (SGR), and survival rate decreases. The control group Tc had the highest percentages of SGR weight (1.16±0.58) and the T3 group had the lowest percentages of SGR weight (0.25±0.77). The hematological assessment showed significant differences of hemoglobin concentration, white blood cell counts and red blood cell numbers between chlorpyrifos treatment and control group (P<0.05). Histological alterations in the liver, gills, and muscle tissues reported to be worse for T3 as compared to others. There were no statistical differences in GSI, HSI values between control and treatment groups. The chlorpyrifos 20 EC was shown to be highly toxic to O. niloticus at sub-lethal dosages.
... The release of pesticides, as a result of agricultural activities can cause freshwater, groundwater and marine water pollution through drainage, leaching, runoff and surface deposition (Radović et al., 2015;Chapman et al., 2016). Water insoluble substances tend to bound to particulate and organic matters and to settle in the sediment. ...
... MS. Although wastewater management has improved, sub-standard treatment of urban wastewaters in Danube tributaries remains a major water quality issue in the DRB [9][10][11][12] . ...
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Dispersed and unknown pollution sources complicate water management in large transboundary watersheds. We applied stable isotopes of water and nitrate together with contaminants of emerging concern (CECs: carbamazepine, caffeine, sulfamethoxazole, perfluorooctanoic acid and 2,4-dinitrophenol) to evaluate mixing and inputs of water and contaminants from tributaries into the mainstem of the transboundary Danube River. Stable isotope ( δ ¹⁸ O, δ ² H) variations from low values (− 13.3 ‰, − 95.1 ‰) in the Upper Danube after the Inn River confluence to high values (− 9.9 ‰, − 69.7 ‰) at the Danube River mouth revealed snowmelt dominated tributary mixing (~ 70%) in the mainstem. Stable isotopes of nitrate ( δ ¹⁵ N-NO 3 ) in the Danube River varied from lower values (+ 6.7 ‰) in the Upper Danube to higher values after the mixing with Morava River (+ 10.5 ‰) and showed that cold snowmelt can reduce biological activity and controls nitrate biotransformation processes in the mainstem up to 1000 km downstream. Data on emerging contaminants affirmed the low biodegradation potential of organic compounds transferred into the mainstem by tributaries. We found pollutant source tracing in large rivers is complicated by mixing of multiple sources with overlapping isotopic signatures, but additional tracers such as CECs improve the interpretation of hydrological processes (e.g., water transit time) and support tracing of nitrate pollution sources, and biogeochemical processes. Our approach can be applied to other watersheds to improve the understanding of dilution and mixing processes. Moreover, it provides directions for improving national and transboundary water quality monitoring networks.
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The surface water quality monitoring network (WQMN) is crucial for effective water environment management. How to design an optimal monitoring network is an important scientific and engineering problem that presents a special challenge in the smart city era. This comprehensive review provides a timely and systematic overview and analysis on quantitative design approaches. Bibliometric analysis shows the chronological pattern, journal distribution, authorship, citation and country pattern. Administration types of water bodies and design methods are classified. The flexibility characteristics of four types of direct design methods and optimization objectives are systematically summarized, and conclusions are drawn from experiences with WQMN parameters, station locations, and sampling frequency and water quality indicators. This paper concludes by identifying four main future directions that should be pursued by the research community. This review sheds light on how to better design and construct WQMNs.
Chapter
This chapter presents information on the temporal and spatial variation of several nutrient concentrations (NH4-N, NO2-N, NO3-N, PO4-P and total phosphorous) over the course of 22 years (1996–2017), based on concentrations recorded at five monitoring stations located along the Lower Danube River (between km 1,071 and km 132), belonging to the TransNational Monitoring Network (TNMN), namely: Baziaș, Pristol, Oltenița, Chiciu and Reni. The dependence of the selected nutrient contents on some hydrological and physico-chemical parameters of water (e.g. discharge, temperature, dissolved oxygen concentration) was also investigated. The results show that, among the analyzed nutrients, the highest multiannual average concentrations are found for NO3-N (1.579 mg/l) and NH4-N (0.238 mg/l) at Chiciu monitoring station, with generally increasing values from upstream toward downstream, while NO2-N concentration is low (less than 0.05 mg/l) and relatively constant along the Lower Danube River. Phosphorus species have multiannual average concentrations ranging from less than 0.15 mg/l, up to less than 0.05 mg/l in the lower part of the studied sector. The mean annual concentrations of nutrients have experienced a general downward linear trend during the period 1996–2017, as a result of a combination of factors. An important role in nutrient load decline was played by the measures to reduce pollution, implemented within the European Union and Danube River Basin. A direct/positive dependance (statistically significant) of the nutrient content on Danube discharge was generally found, and an inverse dependance on water temperature. Although significant decreases in nutrient concentration were noticed, further implementation of measures for reducing nutrient emissions in the Danube River Basin is still required.
Chapter
This chapter provides an up-to-date overview of the flow variability of the Lower Danube River, on a length of about 1,000 km, from the entrance in Romania (at Baziaș) to the beginning of the delta (at Ceatal Izmail or Ceatal Chilia, in Romania). It highlights the spatio-temporal variation of the average, maximum and minimum annual and monthly discharges of the Danube River, at several gauging stations located on the Romanian bank of the river. The analyzed periods range from 44 years (1976–2019) to more than 170 years (1840–2012). Between Baziaș and Ceatal Izmail, the multiannual discharge of the Danube River increased by almost 1,000 m3/s (from 5,551 to 6,516 m3/s, during the period 1840–2012), as a result of tributaries’ contribution from the riparian countries (Romania, Serbia, Bulgaria, Republic of Moldova, Ukraine). The flow regime of the Lower Danube River shows the highest discharges in spring and early summer (April–June, with the peak in April) and the lowest discharges in late summer–autumn (August-November, with minimum in September). During the period 1931–2019, the highest maximum discharges occurred during the historical flood in 2006. They reached 15,800 m3/s at Baziaș and 15,900 m3/s at Ceatal Izmail, but at some intermediate gauging sections the discharges exceeded 16,000 (e.g. 16,300 m3/s, at Giurgiu, 16,200 m3/s, at Oltenița). During the same period, the minimum discharges decreased up to 1,040 m3/s at Baziaș (in 1949) and 1,790 m3/s at Ceatal Izmail (in 1947). The two large dams and reservoirs built on the Lower Danube River within the hydroelectric and navigation systems Iron Gates I and II, did not significantly impair the water flow of the Danube River, but mostly the sediment flux.
Article
A new deep extreme learning machine (ELM) model is developed to predict water temperature and conductivity at a virtual monitoring station. Based on previous research, a modified ELM auto-encoder is developed to extract more robust invariance among the water quality data. A weighted ELM that takes seasonal variation as the basis of weighting is used to predict the actual value of water quality parameters at sites which only have historical data and no longer generate new data. The performance of the proposed model is validated against the monthly data from eight monitoring stations on the Zengwen River, Taiwan (2002–2017). Based on root mean square error, mean absolute error, mean absolute percentage error and correlation coefficient, the experimental results show that the new model is better than the other classical spatial interpolation methods.
Chapter
The rivers and their floodplains are integrated systems. The biodiversity of the Lower Danube River (LDR), in terms of species and habitats, is strongly linked with its hydro-geomorphic-diversity and the natural regions it passes. Human activities, directly and indirectly, are the primary cause which has induced changes in hydrologic regime, longitudinal and lateral connectivity, floodplain geomorphology and function, biodiversity of the river waters and riparian zone. During the twentieth century, particularly after World War II, the LDR has undergone alteration of physical habitat, significant landscape changes, and ecological loss as a result of hydropower damming works and their associated water reservoirs, floodplain embankment, wetlands drainage, chemical pollution, eutrophication, and invasion of exotic species. The extensive embankments and drainage work along LDR in Romania converted about 80% of the annual flooded zone of the floodplain area primarily into agricultural region, obviating its essential connection with the river. Few areas, including reed marshes, meadows, floodplain forests, large shallow lakes, fluvial islands, and the braided section of the river named “the Small Island of Brăila”, have been preserved in natural regime in order to preserve valuable samples of biodiversity, hydro-morpho dynamic processes, and particular fluvial landforms. Most of them are ecotonal areas that have an increased and extremely dynamic biodiversity. This increased turnover of species is exacerbated by anthropogenic factors, which sometimes they can negatively influence certain species of fauna, such as sturgeons, modifying their habitats for reproduction, feeding and resting. After the 1990s, due to the change of the political system in Romania and following integrated programs of the Danube Riparian States, some areas of the engineered floodplain are subject to ecological restoration and integrated management in order to provide convenient ways of reconciliation between nature and human society for a sustainable development. The currently Ramsar and Natura 2000 sites network designed along the LDR provides the national and international legal framework of protection and conservation of wildlife and its habitats. The objectives of this chapter are to present a review of: (1) human interventions from the last century that lead to alteration, degradation, and irreversible losses of habitats along the LDR valley, (2) restoration projects of former floodplain areas, and (3) biodiversity protection and conservation actions carried out over the area in the last decades.
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The responses of river macroinvertebrates to hydromorphological alteration are often considered weak or unclear. It is therefore crucial to verify if and how existing invertebrate-based approaches can reveal the effects of hydromorphological modification. We analyzed the responses of benthic metrics to morphological impairment, with emphasis on the STAR_ICM index, legally required for macroinvertebrate-based ecological status assessment in Italy. A Principal Component Analysis (PCA) was run to condense information on morphological impairment. The major gradient (Component 1) expressed a combination of bank and channel modifications opposed to tree-related features indicating the presence of comparatively unmodified habitats. Jointly, habitat descriptors including Habitat Modification Score (HMS) derived from the application of a habitat survey method were calculated. Spearman rank correlations between biological metrics and morphological impairment indicators (PCA scores and HMS) were significant. A linear mixed-effects regression approach was applied to relate HMS and STAR_ICMi across a wide geographical context. HMS explained > 60% of STAR_ICMi variability, in the absence of apparent water pollution. Results demonstrated that morphological information resumed with habitat survey methods is meaningful for the biological community and that HMS can support the interpretation of ecological status across rivers’ types and in different environmental settings.
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Aim We studied the distribution of freshwater macroinvertebrate taxa and traits to distinguish ecological gradients among the mining‐controlled and natural headwaters, and rural and urban economic activity influences. Location In 2016’s dry season, macroinvertebrate samples were collected at 40 locations in the Mashcon watershed, northern Peruvian Andes. Six locations were in the headwaters directly influenced by mining, eight near‐pristine tributary headwaters, 14 agricultural locations at midstream and 12 urban locations downstream. Methods Eight traits (five biological and three ecological) were selected according to data availability, and modalities scores were assigned using the weighted and the dominant‐trait approaches. The traits relative abundances and abiotic conditions were compared among watershed sections. The ecological interpretability of the ungrouped data was verified with a distance‐based redundancy analysis. Results The high‐altitude mining section had fewer taxa types and abundance, and distinct body forms distributions and prevalent body sizes in macroinvertebrate communities, relatable to the control of the mining headwaters. Physiological and ecological traits (respiration, mobility and attachment, food sources, feeding habits, saprobity and pH preferenda) differed among traits quantification approaches and were less informative at high altitudes. The ecological conditions from the near‐pristine tributaries recovered in the vegetated midstream section, to again be affected in the downstream urban section. Main Conclusions Our results suggest the presence of ecological impairment despite the excellent physicochemical quality of the water discharged by the mine. The obtainment of autecological information at a higher taxonomic resolution, e.g. for ubiquitous taxa like Acari and Chironomidae, would be needed to advance the freshwater quality assessment of ecologically and hydrogeochemically complex Andean mining ecosystems.
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Since groundwater is a major source of water for drinking and for industrial and irrigation uses, the identification of the environmental processes determining groundwater level fluctuation is potentially a matter of great consequence, especially in light of the fact that the frequency of extreme climate events may be expected to increase, causing changes in groundwater recharge systems. In the recent study, data measured at a frequency of one hour were collected from the Szigetköz, an inland delta of the Danube. These were then used to determine the presence, or not, and magnitude of any hidden environmental background factors that may be causing groundwater level fluctuations. Through the application of dynamic factor analysis, it was revealed that changes in groundwater level are mainly determined by (i) the water level of neighboring rivers and (ii) evapotranspiration. The intensity of these factors may also be estimated spatially. If the background factors determined by dynamic factor analysis do indeed figure in the linear model as variables, then the time series of groundwater levels can be said to have been accurately estimated with the use of linear regression. The accuracy of the estimate is indicated by the fact that adjusted coefficient of determination exceeds 0.9 in 80% of the wells. The results, via an enhanced understanding of the reasons for changes in the fluctuation of groundwater, could assist in the development of sustainable water management and irrigation strategies and the preparation for varying potential climate change scenarios.
Article
This paper presents the conceptual framework of a holistic, intelligent decision-support system (IDSS) to plan, manage and optimize water quality monitoring programs (WQMPs) for surface waters. WQMPs are a crucial component of water management because information on water quality is essential when taking action such as legislative compliance, environmental projects, urban and infrastructure development. Planning, managing and optimizing WQMPs is a complex process and requires multiple variables, rules and subject matter expert knowledge. The specific goals of this paper were to (1) assess to what extent the subject domain (WQMPs) is deemed appropriate for an IDSS; (2) describe the design process of the conceptual framework; (3) present the main elements of the system architecture; (4) present two case studies that served as potential end users; (5) illustrate the applicability of the IDSS and (6) describe subsequent steps to further test the IDSS. The IDSS was developed on the premise that the proposed system could (1) improve quality, (2) capture undocumented expertise that is perishable or in short supply (tacit knowledge), (3) provide accessible expertise to novice users, (4) have a training effect on users, and (5) show that the system, even partially complete, could still be useful. Our initial assumptions regarding these points were validated through interviews with subject matter experts. The conceptual framework was designed based on a literature review, interviews with 44 subject matter experts from Europe, Canada and the United States, interaction with end users from two case studies in the Province of Quebec, Canada, and five information technology experts from Canada and Germany. The IDSS presented in this paper will facilitate the planning, management and optimization of WQMPs. It will be exportable to various watersheds and consider the WQMP planner’s need to update the network rapidly if changes occur in human, financial and technical resources. • HIGHLIGHTS • Holistic and adaptable decision-support system to plan, manage and optimize surface water quality monitoring programs • Management and decision support system for knowledge acquisition processes on water quality • System integrates tacit and explicit knowledge on water quality monitoring challenges • Management and decision support system based on tacit knowledge from 44 experts and two case studies • Adapted design methodology for an Intelligent decision-support system
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The Danube is the longest river in the European Union and Europe's second longest river after the Volga. With a total area of 801,463 km² and covering 10% of Continental Europe, the Danube River Basin features the highest degree of cultural diversity in the world and plays a major role in the continent's socioeconomic, political and cultural life. This review aims to assess the evolution of Danube water quality (WQ) over the past decades. By using keywords, a search protocol and filters on the Web of Science platform, a scientific bank of 41 relevant studies was obtained out of the 124 open access articles that were initially available. These papers were closely reviewed. The review's main conclusions are the following: since the beginning of the 1970s, the Danube water regime has changed because of the construction of water reservoirs, dams and hydropower plants. Between 1960 and 1990, nitrogen discharge into the Danube basin has increased about fivefold, whereas phosphate has doubled due to the increase in anthropogenic inputs. Most recently, reductions of nutrient loads were observed, which is linked to political, economic and WQ management changes. Even if at nowadays Danube WQ has an upward trend, the river still shows signs of degradation (mainly organic pollution) downstream of major cities and in some important tributaries. Also, certain specific areas, polluted with substances listed as a priority in the European Water Framework Directive, as well as with newly emerging contaminants, have been identified, which is a matter that requires urgent measures.
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Fine sediment in suspended form, recently deposited overbank and in temporary storage on or in channel beds was collected in the Nene basin during a period of drought through to a period of four high flows. The sediment was analysed for arsenic, copper, lead, phosphorus and zinc concentrations with the aim of investigating their sources, movement, temporary storage and potential for environmental harm.Copper, lead and zinc probably originated from urban street dusts, phosphorus (originally in dissolved form) from sewage effluent and arsenic from natural soils developed over ironstone. There was little difference in the metal or arsenic concentrations in the sediment under different flow conditions; instead proximity to pollutant sources appeared to control their concentrations. Phosphorus in tributary sub-catchments probably adsorbed to sediment during periods of low flow but these sediments were flushed away during high flows and replaced by sediment with lower concentrations. However, concentrations of all pollutants in overbank sediments along the Nene's main channel were not reduced in successive flood events, suggesting no first flush effect. Only phosphorus accumulated on sediment at concentrations exceeding those of its catchment – based sources (e.g. street dusts, channel banks, catchment soils). This scavenging of aqueous phosphate by sediment explained the difference in behaviour between phosphorus, arsenic and heavy metals. The surface area and organic matter content were shown to have a small effect on contaminant concentrations.Street dust contaminants only exceeded predicted effect levels (PELs) in close proximity to urban areas, suggesting a small potential for harm to the aquatic environment. Arsenic concentrations exceeded PELs in most sediment samples. However, it has been shown to be largely non-bioavailable in previously published research on the Nene, limiting its potential for significant environmental harm. Phosphorus concentrations in river sediments are high in comparison to the soils in the catchment and in comparison with sediment-P concentrations in other published lowland catchment studies, indicating a large potential for eutrophication should the Phosphorus be, or become, bioavailable. This article is protected by copyright. All rights reserved.
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Understanding the relationship between river natural and degraded habitats and river assemblages is crucial but yet insufficient for the desired sustainable river management. Our paper therefore compares the relation of river natural morphological features and their modification to benthic invertebrate assemblages among European ecoregions Alps, Pannonian lowland, and Dinaric western Balkan with varied natural characteristics. Morphological conditions were assessed using the habitat quality (RHQ) and modification (RHM) variables, according to Slovenian hydromorphological assessment method, and linked to benthic invertebrate assemblages using multivariate analyses. The overall results indicate markedly higher importance of RHQ variables in comparison with RHM variables for structuring benthic invertebrate assemblages, but reveal important differences among ecoregions. Predominant flow and predominant channel substrate were found among the most important RHQ variables across all ecoregions. Beside these, benthic invertebrate assemblages of the Alps were influenced most by bank variables, whereas of the Pannonian lowland by features linked directly to channel conditions. In Dinaric western Balkan a combination of bank and channel variables influenced the assemblages. Among habitat modification features artificial bank profiles appeared important across all ecoregions. However, in the Alps equal explanatory power was observed for variables water impoundment by weir/dam and bank modifications, whereas in the Pannonian lowland only for variable artificial bank material and even for none in Dinaric western Balkan. According to our findings it is important to consider habitat modification in river management, but more weight should be given to habitat quality features. Moreover, the differences among ecoregions emphasize the need for ecoregion-specific approach.
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Long-term (1960-2005) ecological data were used to identify a regime shift in the northwestern Black Sea shelf and to assess whether it has recovered from its former eutrophic state. Following the collapse of fish stocks and the population explosion of the ctenophore Mnemiopsis leidyi between 1988 and 1991, anthropogenic P-PO4 loads from the River Danube dropped strongly in 1992-1993. This decline in P-PO4 levels was caused by reductions in fertilizer use and emissions from land-based point sources during the economic recession of former Eastern Bloc countries, as well as by the low discharge rate of the River Danube. Commencing in 1993, the phosphate limitation apparently maintained a low-energy, inefficient food web dominated by the dinoflagellate Noctiluca scintillans and jellyfish, and relatively low levels of phytoplankton, bacterioplankton, mesozooplankton and fish. This 'post-eutrophication' regime was markedly different from the classical phytoplankton-mesozooplankton-fish chain of the similarly low nutrient 'pre-eutrophication' regime prior to 1970. Therefore it appears that the food web can attain 2 alternative regimes during periods of low productivity of the ecosystem. The post-eutrophication state cannot be considered as a major improvement or restoration of the northwestern coastal ecosystem.
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1. Introduction Aquatic biological standards, established in law, can be an effective mechanism to promote restoration and ensure the ecological sustainability of aquatic resources (Adler, 2003; Hering et al., 2010). Several countries around the world have established legislation or policies to promote the restoration and maintenance of aquatic ecosystems (CWA, 2006; ANZECC, 2000; EC, 2000). However, the effectiveness of such policy initiatives depends upon the technical clarity of ecological goal statements, and the political clarity of intent that is written into the law. The United States Clean Water Act, for example, states a long-term, national objective to ''restore and maintain the . . . biological integrity of the Nation's waters'' (section 1251). However, the Act does not define the ecological components, or attributes, that constitute biological integrity. Neither does the Act recommend scientific methods to measure the condition of aquatic biota. Rather, the U.S. Clean Water Act delegates the technical implementation of the
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Over the last 20 years, comprehensive strategies for treating measurement error in complex models and accounting for the use of extra data to estimate measurement error parameters have emerged. Focusing on both established and novel approaches, Measurement Error: Models, Methods, and Applications provides an overview of the main techniques and illustrates their application in various models. It describes the impacts of measurement errors on naive analyses that ignore them and presents ways to correct for them across a variety of statistical models, from simple one-sample problems to regression models to more complex mixed and time series models. The book covers correction methods based on known measurement error parameters, replication, internal or external validation data, and, for some models, instrumental variables. It emphasizes the use of several relatively simple methods, moment corrections, regression calibration, simulation extrapolation (SIMEX), modified estimating equation methods, and likelihood techniques. The author uses SAS-IML and Stata to implement many of the techniques in the examples. Accessible to a broad audience, this book explains how to model measurement error, the effects of ignoring it, and how to correct for it. More applied than most books on measurement error, it describes basic models and methods, their uses in a range of application areas, and the associated terminology.
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Background The river Göta Älv is a source of freshwater for 0.7 million swedes. The river is subject to contamination from sewer systems discharge and runoff from agricultural lands. Climate models projects an increase in precipitation and heavy rainfall in this region. This study aimed to determine how daily rainfall causes variation in indicators of pathogen loads, to increase knowledge of variations in river water quality and discuss implications for risk management. Methods Data covering 7 years of daily monitoring of river water turbidity and concentrations of E. coli, Clostridium and coliforms were obtained, and their short-term variations in relation with precipitation were analyzed with time series regression and non-linear distributed lag models. We studied how precipitation effects varied with season and compared different weather stations for predictive ability. Results Generally, the lowest raw water quality occurs 2 days after rainfall, with poor raw water quality continuing for several more days. A rainfall event of >15 mm/24-h (local 95 percentile) was associated with a three-fold higher concentration of E. coli and 30% higher turbidity levels (lag 2). Rainfall was associated with exponential increases in concentrations of indicator bacteria while the effect on turbidity attenuated with very heavy rainfall. Clear associations were also observed between consecutive days of wet weather and decreased water quality. The precipitation effect on increased levels of indicator bacteria was significant in all seasons. Conclusions Rainfall elevates microbial risks year-round in this river and freshwater source and acts as the main driver of varying water quality. Heavy rainfall appears to be a better predictor of fecal pollution than water turbidity. An increase of wet weather and extreme events with climate change will lower river water quality even more, indicating greater challenges for drinking water producers, and suggesting better control of sources of pollution.
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Water protection is one of the most important goals in environmental protection. The Clean Water Act in the USA and the Water Framework Directive (WFD) in Europe are the legal frameworks to facilitate the achievement of this goal. The question is raised of whether more information can be extracted from WFD-related groundwater data. To answer it, a methodology has been developed that is easy to use and could be implemented into official practice. A case study is presented in which the groundwater data of a sodic area in Austria (Seewinkel) is assessed. Eighteen parameters in groundwater sampled from 23 wells (1991–2011) were analyzed. With basic statistics, trend-, cluster-,Wilks’ λ and spatial sampling density analysis, local phosphorus and boron phenomena were described, along with the determining role of sulphate, groundwater flow, and the oxygen gradient in the area. As a final step, the spatial sampling density was determined. Regarding the current set of parameters, all the sampling sites are necessary and only in the case of certain parameters (Ca2+,Mg2+, K+, NO3 −, pH) could one sampling site be abandoned. The methodology applied brings a new perspective to exploring groundwater data collected according to the requirements of the WFD.
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The classification of observations into groups is a general procedure in modern research. However, when searching for homogeneous groups the difficulty of deciding whether further division of a classification is necessary or not to obtain the desired homogeneous groups arises. The presented method, Combined cluster and discriminant analysis (CCDA), aims to facilitate this decision. CCDA consists of three main steps: (I) a basic grouping procedure; (II) a core cycle where the goodness of preconceived and random classifications is determined; and (III) an evaluation step where a decision has to be made regarding division into sub-groups. These steps of the proposed method were implemented in R in a package, under the name of ccda. To present the applicability of the method, a case study on the water quality samples of Neusiedler See is presented, in which CCDA classified the 33 original sampling locations into 17 homogeneous groups, which could provide a starting point for a later recalibration of the lake's monitoring network.
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In most of the world along with urbanization came the deterioration of surface waters. The case of Hungary's Lake Balaton (the largest shallow freshwater lake in Central Europe) and its catchment area was no exception. In the second part of the twentieth century it became clear that measures had to be taken to prevent further water quality deterioration. In order to do so, the Kis-Balaton Water Protection System (KBWPS) was established. To measure its effectiveness in filtering Lake Balaton's water input, total phosphorus and total nitrogen loads are regularly estimated. In this study the practice of temporal sampling frequency estimation is described using data series from the KBWPS in order to suggest a sampling frequency that is suitable for estimating annual nutrient loads and still produces a dataset from which environmental processes can be followed. In this case, temporal sampling frequency estimation was conducted using variogram analysis, before which trend removal was performed on four sampling sites and two daily sampled parameters for the years 1993–2007. Although the calculations were only carried out on two parameters they are applicable to other environmental parameters as well. Nutrient load estimation is used as a verification tool. The result of the variogram analysis pointed towards a three-day sampling frequency for the whole KBWPS in the case of total phosphorus and total nitrogen (if the purpose of the monitoring is nutrient estimation). This reduction in sampling frequency would make an approximately 50% cost reduction possible. The study gives an example of sampling frequency estimation which is a key question in every aspect of environmental science, so that hopefully it will be useful for scientists dealing with water protection issues.
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Assessing ambient exposure to chemical stressors often begins with time-consuming and costly monitoring studies to establish environmental occurrence. Both human and ecological toxicology are currently challenged by the unknowns surrounding low-dose exposure/effects, compounded by the reality that exposure undoubtedly involves mixtures of multiple stressors whose identities and levels can vary over time. Long absent from the assessment process, however, is whether the full scope of the identities of the stressors is sufficiently known. The Matthew Effect (a psychosocial phenomenon sometimes informally called the "bandwagon effect" or "iceberg effect," among others) may adversely bias or corrupt the exposure assessment process. The Matthew Effect is evidenced by decisions that base the selection of stressors to target in environmental monitoring surveys on whether they have been identified in prior studies, rather than considering the possibility that additional, but previously unreported, stressors might also play important roles in an exposure scenario. The possibility that the Matthew Effect might influence the scope of environmental stressor research is explored for the first time in a comprehensive case study that examines the preponderance of "absence of data" (in contrast to positive data and "data of absence") for the environmental occurrence of a very large class of potential chemical stressors associated with ubiquitous consumer use - active pharmaceutical ingredients (APIs). Comprehensive examination of the published data for an array of several hundred of the most frequently used drugs for whether their APIs are environmental contaminants provides a prototype example to catalyze discussion among the many disciplines involved with assessing risk. The findings could help guide the selection of those APIs that might merit targeting for environmental monitoring (based on the absence of data for environmental occurrence) as well as the prescribing of those medications that might have minimal environmental impact (based on data of absence for environmental occurrence).
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Microbial source tracking (MST) is a sub-discipline of environmental microbiology that has emerged and grown in response to the inability of conventional fecal indicator bacteria (such as Escherichia coli and enterococci) to discriminate among the many possible sources of fecal pollution in environmental waters. MST’s current and potential applications range from beach monitoring to total maximum daily load (TMDL) assessment of pollution sources, which in turn will mediate greater protection of public health and improvement of environmental water quality. This comprehensive book taps the expertise of many of the leading research scientists from an international assemblage, and considers a geographic range from the U.S. to China, New Zealand, Australia, and the EU. It addresses subjects ranging from the fundamentals of MST methods, their pros and cons, and performance criteria necessary during method development, and application, to case studies from beach, agricultural, and urban watersheds. Separate chapters focus on viral-, protozoan-, chemical-, and mitochondrial DNA-based methods. Specialized topics include legal and TMDL-associated issues, public perceptions, statistical analysis, food safety, national security, and using MST in undergraduate education. The audience for this work will include advanced undergraduate and graduate students from scientific and engineering disciplines who are interested in microbial water quality, research scientists, regulators, and others interested in the fundamentals, applications and interpretation of MST methods and data.
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Since the beginning of 2001 scientists from 7 countries have been working within a 4 year EU 5th framework project, co-ordinated by the Vienna University of Technology (Prof. Kroiss, Institute for Water Quality and Waste Management). The main objective of the project aims at a better understanding of the nutrient management in the Danube catchment area and its influence on the Black Sea ecosystem. First results show a positive development of the near bottom oxygen regime in the Danube riverwater - influenced shallow zones of the North Western Black Sea. This is mainly due to the considerably reduced Danube nutrient discharge over the last 10 years, following the collapse of industry and agriculture in the former soviet countries of the Danube catchment area. Reduced phosphorous loads of the Danube caused a considerable decrease in phytoplankton mass development in the riverwater - influenced Black Sea regions. Diatom species again began to dominate the dinoflagellates over the last 10 years. Following an increase in the N/P ratio, phosphate has become the limiting factor for primary productivity in this region over the last 5 years. The species diversity of macrozoobenthos has also increased since 1996 in front of the Danube delta. No regeneration can be recognised with regard to the higher members of the pelagic foodchain: The ctenophore Mnemiopsis, which was introduced to the Black Sea by by man 20 years ago, as well as the indigenous medusa Aurelia aurita still dominate the zooplankton. The grazing pressure of these species apparently does not allow a regeneration of fish populations in the western Black Sea.
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Provides a detailed critical and comprehensive review of the use of the whole spectrum of animals and evaluates their usefulness as monitors. The text is divided into chapters discussing terrestrial, freshwater and marine environments. A further division separates consideration of metal contaminants and organic (pesticides and hydrocarbons) contaminants. Other chapters deal with the issues of the biological effects of marine oil pollution, bioassays, microcosms and radionuclides. Acid precipitation is considered in Chapter 3, which incorporates other aspects of monitoring in the freshwater environment. There is a glossary of pesticides, and a subdivided species list giving Linnean and common names and their occurrence in the text. With the 3 main chapters divided into "metals' and "organics', animal groups are considered systematically, starting with invertebrates such as earthworms and woodlice, and finishing with the large mammals. -from Author
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The surface water quality characteristics of Lake Ontario were studied during 29 cruises conducted on a monthly basis throughout 1977, 1981 and 1982. El-Shaarawi and Shah 's (1978) classification procedure was first used to reduce each year 's multi-cruise information (each cruise sampling 94 stations for 14 parameters) to a single value (T) for each station and year. Principal components analysis was then applied to these T-values, reducing the multiple parameter list to 3 factor scores. Ward 's clustering procedure grouped together stations, according to their factor scores, which demonstrated similar properties. These groups, or zones, were then validated using discriminant analysis.
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Microbial source tracking (MST) is a still-new and emerging sub-discipline of Biology that allows practitioners to discriminate among the many possible sources of fecal pollution in environmental waters. MST’s current and potential applications range from beach monitoring to total maximum daily load (TMDL) assessment of pollution sources, that in turn will mediate greater protection of public health and improvement of environmental water quality. This comprehensive book taps the expertise of many of the leading research scientists from an international assemblage, and contains chapters that range from China and developing nations (22) to New Zealand and Australia (21), plus the EU and USA. The book addresses subjects ranging from the fundamentals of performance criteria during method development (2), library-dependent (3) and library-independent (4) approaches with their pros and cons, and applications to case studies from agricultural (18), urban (19), and beach (20) watersheds. Separate chapters focus on viral (5), bacteriophage (6), protozoan (7), chemical (8), mitochondrial DNA (10), and community analysis (11) -based methods. Chapters that relate MST to the fecal indicator bacteria (15), determining when and where to use MST (16), and the environmental persistence of fecal bacteria (17) put MST in the context of environmental monitoring. Specialized topics include legal (13) and TMDL (14) -associated issues, public perceptions (12), statistical analysis (9), national security (23), risk assessment (24), food safety (25), and using MST in undergraduate education (26). We hope that this book will prove useful to new practitioners of MST as well as established researchers and scientists and that it will serve as a valuable reference for many years to come.
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The paper assesses the impact on the fluctuation of the shallow-groundwater table of the diversion of the Danube upstream from the Gabčikovo/Bős hydroelectric power plant in a hydraulically connected, geologically identical, and structurally not decomposable geological area in North-West Hungary. On the basis of shallow-groundwater level monitoring data the impact was traced back to the effect of the Danube’s changed flow course, and quantized for the whole study area. To this end the influence of the river had to be separated from the effect of precipitation. The means chosen was the application of dynamic factor analysis to the registered hydrograph time series. We conclude that the originally homogeneous and dominant effect of the Danube has split and now consists of a diverted and a returning component (downstream from the power plant), and that this is a likely cause of ram-effect and river bed clogging. Furthermore the effect of precipitation ceased to be suppressed, and came to the fore.
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As the most international catchment worldwide, the Danube River Basin (DRB) faces different pressures affecting both aquatic and terrestrial ecosystems; these pressures encompass pollution (e.g. nutrients and xenobiotics), hydromorphological river alterations (navigation, hydropower and fl ood protection), land use change, invasive species, overexploitation, and climate change. Of special value in the DRB are the still existing floodplains as hotspots of biodiversity and multiple ecosystem services; hence, they deserve closer attention of conservation (e.g. nature parks), restoration and sustainable management strategies. Science proof criteria are integrated into river basin management policy by applying several basic principles (e.g., polluter/user pay, best available technique, precaution, subsidiary, solidarity), transparent planning with public participation and an integrated sustainable approach. This strategy is discussed with reference to implementation in the DRB under the EU Water Framework Directive (WFD).