László Koncsos’s research while affiliated with Budapest University of Technology and Economics and other places

The pursuit of good management of our waters poses permanent challenges to the whole society. Decision-makers often need to define appropriate and sustainable strategies on interdisciplinary topics, like water management issues. The rapidly evolving quantification and mapping of hydrologic ecosystem services (HES) is putting hydrologic and water management issues into an ecosystem services (ES) framework, which can be a step towards reconciling different aspects of land use and water management. Different tools can be used for modelling HES, with a wide range according to their basic properties, e.g., structure, methodology, computational needs, data requirements, reliability, controllability. As a result of that, the numeric values, spatial patterns, and reliability of HES assessments and the uncertainties in their results may differ significantly.In this paper, we covered almost the whole palette of HES mapping tools with regards to modelling approach: we used InVEST, SWAT and two novel rule-based matrix models for the same pilot area, the 1530 km2 hilly catchment of the Zala River (Hungary). We mapped three HES: flood control, erosion control and nutrient (total phosphorus) retention. Our aim was to examine the relevance of the differences between the HES mapping tools through analysing the spatial differences between the results obtained with the applied. We carried out spatial similarity tests and hotspot analysis at the computational unit level for the individual HES and in an aggregated way as well.As a result of the spatial pattern similarity tests, InVEST and the matrix models showed moderate to strong correlation (p

The floodplains of the Tisza River, stretching across the eastern part of Hungary, are often affected by riverine and inland excess water flooding and draught. This paper investigates a possible solution to this problem utilizing the water retention capabilities of old floodplains. In this study, the effect of the position of the inlet structures of a floodplain, near Csongrád town, was examined with HEC-RAS 1D-2D coupled model. Based on the results, the rules of the deep floodplain selection were determined. On the extended model, the possibilities of a deep floodplain storage area chain have been explored. According to the estimate, more than 2.36 km ³ potential storage capacity is available along the Hungarian section of the Tisza River.

During the 20th century in the Hungarian lowlands the emphasis was put on maximizing provisioning ecosystem services (ES), which caused the weakening of regulating and other services. With the growing environmental pressures, it is crucial to apply a more adaptive landscape management. This, however, leads to territorial conflicts, as large areas with water-tolerant land cover (i.e., wetlands, meadows, riparian forests) are needed to buffer extreme hydrological events.We present some findings of the WateRisk project, a research that focused on the possible solutions of these conflicts. In a scenario-based case study, we analyze the outlined issue for the Szamos-Kraszna Interfluve, a 510 km2 lowland catchment heavily affected by excess water. Scenarios were evaluated with an integrated methodology that focuses on the water budget and the total values of ES. The efficiency of the drainage network was found to be minor/moderate as it provided only -1–5% reduction in the spatial extents of inundations, and it contributed only ~20% to the elimination of water coverage. Furthermore, comparing the present (defense-focused) and the alternative (water retention focused) scenarios, the latter turned out to provide higher monetary value for the summed individual and social benefits of ES. This underlines the need for extensive adaptive measures in both water management and landscape planning to create resilience and the ability to cope with contemporary environmental challenges.

A country scale analysis of diffuse source nutrient emissions have been undertaken previously on small catchments level using the MONERIS model, which needed a proper estimation of surface and subsurface runoff differentiation to support or contradict its own water budget based method. As reliable, country scale base flow estimation has not been available for the country at the time of the study, this knowledge gap has been tried to be filled by the current work. This has been done using multiple methods. Digital filter have been applied on continuous river discharge data on gauged catchments in order to determine base flow indices (BFI). Using multiple linear regression (MLR) and artificial neural networks (ANN), climatic, soil and land use properties of the catchments have been used to extend base flow indices to ungauged catchments. MLR brought acceptable results (adjusted r 2 values around 0.7), however it proved to be sensitive of the selection of catchments used for validation, and therefore a mean of prediction by thirty different regression equation was used for the estimation. ANN was less sensitive for the change of the variables included and the number of nodes used for the learning. The results are comparable with the MLR method and show good agreement in most of the areas, however in some part of the country the two approach show significant differences in the predicted BFI values.

Water quality models have been under constant development in the last decades. It is a tendency to build robust deterministic models characterized by high data demand in order to get knowledge on non-monitored elements of the stream network. However, based on simple descriptions of the water quality processes many statistical parameters of the concentration time series can be extended to arbitrary point of the stream network. This paper proposes a method for the extension of statistical parameters of concentration along a river network. The proposed method is based on the extension of the idea of linearization. Investigating a single river reach, supposing a simple in-stream process (e.g. 1 st order decay), the downstream mean, standard deviation and correlation values can be calculated via Taylor-series approximation. Also, approximations can be given for values below a confluence of two rivers, if upstream values are known. The proposed method is tested against: 1. Synthetically generated flow and water quality data, where parameters of the data generation are derived based on long-time measurement data. 2. Measured upstream data, and elements of the downstream data series that are calculated one by one based on simple equations describing the in-stream processes. In the 1 st test, upstream daily discharge, BOD concentration and water temperature values were generated synthetically. Statistics of a hypothetical downstream point were calculated (supposing realistic river geometry) in two ways. 1. The downstream concentration was calculated on a daily basis assuming 1 st order decay. Statistical values were calculated from the daily downstream concentration data series for each year ("daily"). 2. With Taylor-series approximation ("approximated"). The approximated statistics showed promising agreement with values calculated on a daily basis. Approximated mean values of the downstream concentration had an error of-10 … 1% relative to the mean calculated on a daily basis. Approximated standard deviation of the downstream concentration had an error of-8 … 9% relative to the standard deviation calculated on a daily basis. The relative error exceeded 5% only in 4% of the cases. As for the correlation between discharge and downstream concentration, the difference between approximated values and values calculated on a daily basis ranged-0.04 … 0.21. It exceeded 0.05 in only 6% of the cases. Concerning the correlation between temperature and downstream concentration, the difference between approximated and calculated values ranged between-0.10 … 0.11. The difference exceeded 0.05 only in 3% of the cases. Investigating a confluence of two rivers with synthetically generated realistic data, the most statistical properties downstream to the confluence could be approximated with very little error relative to the ones calculated on a daily basis.

A methodology is proposed to calculate statistical average and standard deviation of long time water quality parameter series along a river network. The method considers the water network as a graph consisting of straight sessions and junctions. With a Taylor-series approximation, statistical values of an arbitrary point of the network can be calculated from upstream ones without the need to calculate the single downstream values. According to preliminary results of the first calculations on a pilot area, mean value of the downstream biological oxygen demand and the so called 'transfer coefficient' can be approximated with a relative accuracy of 10%.

An integrated hydrological model has been applied for small rural-urban catchments at the Tisza-Maros confluence using the WateRisk integrated hydrological model system. The aim of the hydrological simulations was to identify the role that the relief plays in the runoff generation process, and to highlight the relationship between the precipitation, runoff and the depression’s water storage of the relief. The overall aim is to support the description of contaminant (phosphorus) transport processes with knowledge about the rainfall-runoff-storage relationship, described with the complex deterministic hydrodynamic model system. To support this aim the rainfall-runoff and the one-dimensional flow routing modules have been used in the model. Results suggest that the depletion of the surface depressions water storage capacity is a non-linear saturation type function of the amount of rainfall falling on the surface. Manning n values of the drainage channel system might also have strong influence on runoff dynamics.

Efficient solutions to flood and water logging problems are hardly achievable without flexibility in land use and management. This report considers how the use of economic policy instruments (EPIs) can improve the flexibility of land use and thereby contribute to more cost-effective flood protection and offer solutions to water logging problems. Two case studies have been conducted within the Tisza river basin of Hungary to explore if innovative EPIs can be applied in water management - with a vision to improve social welfare. The case study was prepared in the EPI Water research program (Evaluating Economic Policy Instruments for Sustainable Water Management in Europe - www.epi-water.eu

Physical and hydraulic soil properties are essential input parameters for models from different sciences (e.g. hydrology, agriculture, water management, nature preservation). Generally texture composition, porosity and other easily measurable physical properties of soils are known. However, saturated hydraulic conductivity and characteristic values of the water retention curve are usually missing information. Therefore, based on the physical similarity of soils (classes), they are substituted by data derived from soil databases. The aim of this study was to assess the currently unknown uncertainties of such classified databases. To do so, a large variety of tests were carried out: (i) static and dynamic, (ii) 1D and 3D (iii) hydraulic and hydrologic applied tests, (iv) real and synthetic soils, parameterized accordingly, and (v) HUNSODA and/or HYPRES databases. The results were sorted with respect to FAO and USDA classification systems. Soil class overlapping was evaluated through the statistics of basic hydraulic parameters (retention curve, hydraulic conductivity). Indicators related to hydrologic extremities (excess water and drought) were used to quantify the uncertainties of soil texture based on parameter substitution. It was concluded that the two evaluated soil classification systems did not sort soils reliably from the hydrologic and hydraulic viewpoint: the test results of classes showed major overlaps. Moreover, in most cases class synthetic parameter combinations poorly represented real soils. As a general consequence the results based on classified soil databases should be accepted only with reservation.

An essential input for environmental studies, especially for hydrological simulations is the soil information, which is usually provided by spatial soil databases. Despite the growing number of related analyses little is known about the uncertainty associated to databases. This study aimed to evaluate this issue. (i) the World Soil Classification System was used to classify soil horizons of the Unsaturated Soil Hydrologic Database of Hungary, (ii) the resulting soil classes were statistically analyzed, (iii) various static measures were derived and dynamic numerical simulations were carried out to assess the uncertainties of the classification method from hydrologic viewpoint. The results question the reliability of the FAO method.