Environmental Earth Sciences

Published by Springer Nature
Online ISSN: 1432-0495
Print ISSN: 0943-0105
Learn more about this page
Recent publications
We present compelling evidence that supports our contention that aerosolized coal fly ash particles are the main agents responsible for stratospheric ozone depletion, not chlorofluorocarbon gases. Aerosolized coal fly ash particles, uplifted to the stratosphere, not only serve as ice-nucleating agents, but are trapped and concentrated in stratospheric clouds, including Polar Stratospheric Clouds. In springtime, as stratospheric clouds begin to melt/evaporate, said ozone-consuming coal fly ash particles are released making them available to react with and consume stratospheric ozone. Ceasing to contaminate the environment with aerosolized coal fly ash will decrease stratospheric ozone destruction, reduce global warming, and will significantly improve human and environmental health.
Kant's 1755 hypothesis on the origin of the sun and planets, as modified by Laplace, foreshadowed the modern protoplanetary theory of planet formation in which planets were thought to form at very high pressures from within giant gaseous protoplanets. The protoplanetary theory was popular in the 1940s and 1950s, but was abandoned and ignored by phenomenological model-makers in the early 1960s who favored the planetesimal theory, the idea that planets formed by the progressive accumulation of dust that had condensed at very low pressures. Here, I validated the protoplanetary theory by:  Thermodynamic considerations;  Observations of internal magnetic field generation;  Observations of Mercury; and,  Observations of Earth's behavior. Although the planetesimal theory did not account for solar system formation, some of its elements added a veneer of oxidized material to the outer portions of Earth, especially oxidized iron which is critical for the development of life.
On 7th of August 2020, a M w = 4.9 earthquake occurred in Mila province (Northeast Algeria). Consequently, more than 2000 houses were indirectly affected (partially damaged or collapsed) within 10 km from the earthquake's epicenter, in the locality of El Kherba. According to field surveys conducted 3 days after the earthquake, damages and casualties were directly linked to an earthquake-induced landslide that occurred after the main shock. This was evidenced by numerous cracks in the site's soil mainly perpendicular to the landslide direction. Local characteristics (i.e., geology, geomorphology) and anthropogenic activities expose this area to landslide hazard. This study shows the reliability of the ambient noise horizontal to vertical spectral ratio (HVSR) method in the characterization of an active landslide. Ambient noise records were processed through spectral ratio techniques to identify the landslide's geometry based on spectral responses analysis. The obtained results allowed the landslide's slip surface mapping and boundary delineation, which correlates well with the field observations. After the rotation of the signal's horizontal components, large variations in the experimental spectral ratios, in both amplitude and direction, revealed site effects (soil remoulding, crack network) on the soil dynamic behavior.
Evaporation acts as an important component and a key control factor in land hydrological processes. In the context of global warming, pan evaporation demand is expected to increase, but the decrease in measured pan evaporation has challenged the hypothesis that climate change would increase evaporation. The main purposes of this study were (1) to investigate the existence of evaporation paradox, (2) to detect the temporal trends of pan evaporation and related climatic variables on annual time scale. In this study the data of 50 synoptic weather stations in half-west and center of Iran were used. Non-parametric tests Mann-Kendall and Sen's slope estimator were used to discover trend through time series. Results showed that pan evaporation in 10% and 28% of stations had significant (p<0.05) decreasing and increasing trend, respectively. But, trend analysis of mean temperature as source of energy required for evaporation, indicated that in 94% of the stations had increasing trend. Despite the increase in temperature in the all stations, evaporation paradox has occurred in 36% of stations and only in 10% of stations evaporation paradox was significant at 5% level (p<0.05). Data analysis in stations that had evaporation paradox ( with negative pan evaporation trend) indicated that decrease in wind speed and sunshine duration and more increasing in the minimum temperature compared to the maximum temperature, were the main climatic parameters that controlling the rate of pan evaporation. Decreasing in pan evaporation in arid and semiarid areas of Iran is important in climatic studies.
The study examined the physio-chemical characteristics of some selected ground water within the Federal Polytechnic, Ado Ekiti. Ten boreholes were selected due to their frequency and proximity to use by both students and staff of the institution and represented with codes A1 to A10. Each sample was taken directly from the borehole through the connecting riser pipes and stored in a 2ml sterilized PVC bottle, temperatures measurements of each the samples were taken immediately with Hanna portable thermometer, ice packed cooler were used to preserve the samples on site before onward transit to the Water/Public Health Laboratory of the institution where the samples were subjected to physico-chemical analyses. Water properties such as temperature, colour, odour, turbidity, pH, total alkalinity, chloride, iron, zinc chromium and manganese were investigated according to guidelines set by APHA 2005. Test results obtained from colour, odour turbidity, total alkalinity, chlorides, iron, Zinc of all the samples analyzed were found to be within the limit as set by the Nigerian Standard for Drinking Water Quality (NSDWQ). While chromium concentration in all the samples were above the permissible standard of 0.05mg/l except for the sample at location A10 which had no reading. Manganese concentration in 3 boreholes (A1, A4, and A8) were above the permissible limit of 0.2mg/l. It is recommended that the 10 boreholes should be subjected to both primary and secondary treatment before consumption.
A mechanism of earthquake generation by reservoir impounding is proposed here with particular application to the Brazilian cases and to areas subject to low confining stress condition in stable regions. Six artificial lakes are described and the associated earthquake sources are discussed in terms of natural or induced seismicity.
A study involving soil radon monitoring using RAD-7 instrument was carried out near Balakot-Bagh (B-B) Fault line hit by a 7.6 magnitude earthquake in October 2005. The study aimed to determine the spatial distribution of soil radon gas levels and the relationship between the soil radon gas and fracture density. Eleven soil samples were collected near the fault line, and 56 more samples (fourteen each from the adjoining district/area). Field measurements were made in the summer season of 2013, as a part of continuous measurement for regular monitoring the area for radon emanation and for observing the anomalies with previous values. The study area is located in Lesser Himalayas, North Pakistan, the Balakot–Bagh (B–B) fault in the Hazara–Kashmir Syntaxis. Soil gas radon concentrations were found higher near the Balakot-Bagh Fault line with an average value of 11.9kBqm−3 compared to other sites of the study area with an average value of around 6.5 kBqm−3. The radon value near the fault line is 70% higher as compared to the surrounding area.
western part of the Governorate and Lake Razaza in the north of the region, while in the western and southern part of the region is Anbar Governorate and geographically (43° 10′ 25.7″, 43° 39″ 0.3″) longitude and (32° 10′ 25.7″, 32° 36′ 25.7″) latitude. The area of study is about 2400 Km2. The groundwater modeling system (GMS) v10.3 program was used for the modeling of ground water in the area containing about 22 wells distributed throughout the study area and the discharge of these wells ranges from 7 to 100 l/s and the rate of discharge of these wells up to 36 l/s. The model was initially operated within a steady state and after obtaining a match between the models results with the initial values of groundwater levels, the results of this case were adopted as inputs to run the model within the unsteady state. The model was worked within the sight of the above wells for 3 years and the results of the operation indicate a decrease in groundwater levels ranging from 2 to 21 m distributed uniformly throughout the study area.
Groundwater from 73 municipal and 21 private wells were analyzed for Ag,Al, As, B, Ba, Cd,Co, Cr,Cu, Fe,Hg,Li,Mn,Ni,Pb,SrandZnovera 3 yearmonitoring program in theGaza Strip. The results show that the trace elements of the groundwater of the Gaza Strip do not generally pose any health or environmentalhazard. In spite of that, only 10%of themunicipal wells meet theWHOstandards. Cl-,NO3 ) and F- concentrations exceeded 2–9 times theWHOstandards in 90% of thewells tested with maximum concentrations of 3,000, 450 and 1.6 mg/l, respectively. Several private wells should not be used for drinking purposes as the average of Zn, Cd, Pb, Fe and As was 58, 30, 270, 468 and 10 lg/l, respectively. A severe water dilemma will appear in the near future from both quality and quantity aspects.
In the present study, the quality of groundwater and the effects of pumping on the phreatic surface beneath the Zanjan Plain located in northwestern Iran were investigated by measuring water levels in 81 observation wells as well as various physicochemical parameters including electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH) and pH. In addition, the results of the chemical analysis of major anions and cations from 53 boreholes that were sampled during the period 2004–2018 were evaluated. The water level measurements indicated that the elevation of the phreatic surface had declined by up to about 8 m during the studied period, indicating an average decrease of about 0.57 m per year. A comparison of the measured physicochemical parameters with WHO, ISIRI, and EPA standards for drinking water quality showed that some parameters including EC, TDS, TH, SO4, and Cl in the northwestern and central parts of the plain exceeded the allowable level. An assessment of water quality index (WQI) values showed that most parts of the Zanjan Plain lie in the “good” quality class, although in some parts, the water quality of “poor” quality class, most likely due to the effects of urban activities. A comparison of the results from a Schoeller diagram assessment with WQI values showed some differences between the results of the qualitative classification of some parts of the Zanjan Plain groundwater based on the two mentioned methods. The results of the present study showed that groundwater of some areas of the Zanjan Plain is not suitable to be used for irrigation of agricultural lands with limited drainage. The Piper diagram also indicated that the dominant groundwater quality facies on the Zanjan Plain were Ca–Na–HCO3 and Ca–HCO3 water types. The results of the Spearman correlation analysis also showed a high correlation of most anions with cations. Analysis of the volume changes versus qualitative changes in groundwater also showed a general decreasing trend of water quality with decreases in the volume of groundwater in storage in the aquifer, although in some conditions due to changes in solubility of water-soluble materials because of the changes in groundwater level, other trends were also observed.
Land use/cover statistics resulted from the classification process
The land cover change in feddan between the year 1990 and 2015
Land Reclamation Areas identified by past national plans for desert reclamation plans till 2017
the amount of change in agricultural area for the High land including the development areas for land use subarea (A, B) during the period 1992-2015.
Egypt has turned its attention to develop many new areas for agricultural development, such as the fringes of the Nile Valley, the eastern, western fringes of the Nile Delta, and also to the desert areas. In this research, integration of GIS and remote sensing (RS&GIS) were used in the South Eastern Nile delta region to follow the change in land use/cover and to assess the change in the agricultural lands in the desert areas. Three satellite images for years 1992, 2002, 2015 were used to produce the land use/cover maps using the maximum likelihood method by selecting five classes for land cover as (Agricultural, water, desert, and urban). The results of the accuracy assessment were evaluated as 85%, 86.2%, and 87.5% for the years 1992, 2002, and 2015. The change detection maps were produced between (1992-2002), (2002-2015) and (1992-2015). To follow up the increase in reclaimed areas that previously planned for reclamation by the National Water Resources Plans. More change detection statistics were performed. The results showed an increase in the area of agricultural lands within the desert regions, with values that are aligned with the areas proposed in the previous national water plans. The area of reclamation lands of the existing reclamation projects started before 1992 increased by 17527.6 (feddan) from the year 1992 to 2015 compared to 115436 feddan for the reclamation lands planned by the Land master plan from (1992 to 2017) for the same period of years. Finally, we can consider the integration between GIS and remote sensing data as an important and powerful tool for accurately detection land use/land cover changes over the study area. Also, these tools were considered very useful for the planning of sustainable management for water resource plans.
Finite element method (FEM) is a numerical technique for solving Engineering problem and Mathematical Physics. Useful problems with complicated geometries, Loading, and material properties where analytical solutions may not be obtained. Some of the complicated problems involving load is a cylindrical Reservoir structures where crude oil is stored in a Tank Farm. This paper demonstrates the use of Finite Element Analysis in above surface cylindrical Reservoir Engineering Structure. The reservoir which has sixteen (16) monitoring station was monitored using reflectorless Total station. This paper is the second phase of our pilot model and we hope to developed this second phase further to cover nine studs. The studs covered ranges from northern part of the Reservoir to the southern parts to further test the application of FEM triangular shaded (Truss) elements. Keywords: Crude Oil, Finite Element, Reservoir, stiffness matrix, Strain and stress analysis.
Groundwater quality in the Santo Domingo Irrigation District area in Baja California Sur, Mexico, indicates the presence of various salinization processes, (1) the geological matter of marine origin comprising the aquifer material suffers diagenetic effects due to its interaction with groundwater of low salinity, (2) the effects of intensive agriculture practices produce effluents that infiltrate to the saturated zone, and (3) the extraction of groundwater causes modifications in the natural flow system induces lateral flow of seawater from the coast line. However, groundwater management has been carried out with the belief that the latter is the main source of salinization. This has resulted in a policy of installing wells increasingly far from the coast, which is not solving the problem. Irrigation-return and seawater that remains in the geological units have been identified as major sources of salinization. Controls should be imposed when installing wells in contact with clayey units that form the base of the aquifer. Extracted groundwater consists of a mixture of (1) groundwater of relatively low salinity that circulates in the aquifer and (2) an extreme member with salinity different to seawater contained mainly in formations that have low permeability, which limits the aquifer underneath. The geochemistry of carbonates and cation-exchange reactions (both direct and reverse) control the concentration of Ca, Mg, Na, and HCO 3 , as well as pH values. The concentrations of dissolved trace elements (F, Li, Ba, Sr) suggest that the extreme saline member is different from the average seawater composition. A distinction between the salinization caused by farming practices and that blamed on seawater is defined by the use of NO 3 .
Himalaya of Nepal is recognized as the rich source of medicinal herbs. Impacts of climate change are serious issues especially in this region and the resultant effects are on the natural resource equally. However, there is very limited research related to this in high hill of Nepal. Thus, this research was objectively conducted to assess the trend of temperature, rainfall and their impact on production of medicinal plants. Humla district was selected as the study site. Observation, household survey, FGD and KII were applied to collect primary data. While secondary data was collected from DHM, DFO and other related governmental agencies and authorities. The trend analysis of maximum temperature showed the increasing trend in Humal district. The recorded temperature was the highest 18.7 0 C in 2003 which was the lowest only 5.0 0 C in 1991. The minimum temperature was also increasing from 1990 to 2018 which was the highest 6.4 0 C in 2018 but it was the lowest-2.5 0 C in 1997. The estimated annual rainfall was deceasing by-5.1313 mm every year from 1980 to 2018. In fact, it was the highest 1750 mm which was declined to 400 mm in years 1982 and 2001. The production of Morchella esculenta (Guchhi chau) is generally related to the annual rainfall. The rainfall record of 2010 was not available but the most of the people shared that there was more rainfall in this year so the production of Morchella esculenta was the highest 13496 kg in 2010. It was found that the production of Delphinium himalayai decreased with increased of temperature. It was found that the production of Nardostachy grandiflora was the highest 36429 kg in 2009. Rheum australe grows in cold arid climate but thesedays the production had been decreased from 2005. Paris polyphylla grows best in warm temperature so the production had been increasing. The production of Swertia chirayita was the highest in 2010. The impacts of climate change were positive as well as negative on the production of medicinal herbs. Therefore, this study will be useful to understand the impact of climate change on medicinal herb in Himalaya.
In this work, two methods were used to assess the groundwater natural recharge of the Sisseb El Alem Nadhour Saouaf basin (SANS) in Northeastern of Tunisia. In fact, the natural recharge of the SANS aquifer remains a major unknown for hydrogeologists and decision makers. Based on the various databases that include geology, sedimentology, hydrology, geochemical and isotopic data, the groundwater natural recharge was estimated using two different approaches. In a first approach, a historical measurement of tritium, the radioactive isotope, was used to calculate the age of modern groundwater (< 50 years). The application of the tritium radioactivity model shows that in the SANS basin the renewal rate of groundwater ranges between 1.3 and 3%. However, this is difficult to generalize across the entire aquifer, given the large spatial and temporal variations of rain, and the uncertainty affecting the measurement of tritium rates in rain, as well as the uncertainty of the used radioactivity model. In the second approach, a quasi-steady hydrological model called the WetSpass model (Water and Energy Transfer between Soil, Plants and Atmosphere under quasi-steady state) was used to assess the spatiotemporal variability of the recharge. The results show that the average annual recharge between 1971 and 2016 is 10 Mm3/year. A value that remains minimal and that characterizes this kind of arid region. The spatial distribution maps of the recharge show that the maximum recharge occurs in the northwest edges of the basin, west and in the southern part, at the level of the outcrop permeable formations of the aquifers. Finally, the two methods used show that the groundwater natural recharge is very heterogeneous and limited in time and space. However, these results remain a further step to ameliorate the water budget of the SANS basin to perform a realistic hydrogeological model.
Parameters of the applied thermal imagers
This Budapest is justly famous for its thermal springs emerging in the zone near the bank of the Danube. However, it is less known that apart from springs on the riverbank, so-called drowned springs also emerge in the bed of the Danube, whose water of considerable volume flow and heat quantity discharges into the river unused. Drowned springs are natural discharges of the Buda Thermal Karst. Their volume flow and temperature are affected by stage changes of the Danube, being in close hydrodynamical relationship with the springs. Our investigations focused on the detection and location of these drowned springs-which emerge in the Danube riverbed and are assumed to have a high volume of flow-by aerial remote sensing. We have tried to detect the underwater springs near Margaret Island with low altitude aircraft and UAV flights and modern digital thermal imagers. We were looking for a quick and economical method which we can quickly map large areas before we survey the key spots from boats.
Location map of the study area displaying the boundary of Yok Don National Park (yellow polygon) in Central Highlands region, Vietnam.
The distribution of the location of sample plots established during field survey over the RGB color composite images: (a) Dry season RGB image, and (b) Rainy season RGB image. The RGB color composite image was created by using the HH channel for red (R), HV channel for green (G), and the ratio HH/HV for blue (B).
Cross-comparison between different structural parameters: (a) tree height (H) and diameter at breast height (D), (b) density of trees (N) and diameter at breast height (D), (c) density of trees(N) and tree height (H), (d) woody volume (V) and basal area (BA), (e) above ground biomass (AGB) and basal area (BA), and (f) woody volume (V) and above ground biomass (AGB).
The relationship between biomass, woody volume, and backscattering intensity during dry season: (a) Biomass versus backscattering intensity (HV), (b) Woody volume versus backscattering intensity (HV), (c) Biomass versus backscattering intensity (HH), and (d) Woody volume versus backscattering intensity (HH).
The relationship between the woody volume, biomass, and backscattering intensity during rainy season: (a) Biomass versus backscattering intensity (HV), (b) Woody volume versus backscattering intensity (HV), (c) Biomass versus backscattering intensity (HH), (d) Woody volume versus backscattering intensity (HH).
The potential of Synthetic Aperture Radar (SAR) data based on ALOS-2 satellite operating in L-band radar was assessed for the estimation of biomass and woody volume in tropical dense forests in Vietnam by collecting in situ forest data in 2015. The effect of polarization and seasonality of the SAR data on the biomass and woody volume was analyzed. The combination of HH, HV, and HH/ HV variables using multivariate linear regression did not improve the estimation of biomass and woody volume compared to using the HV channel independently, as the HH and HH/HV variables were not statistically significant (p-value>0.05). The dry season HV polarization could explain 65% and 58% variation of the biomass and woody volume respectively in the tropical forest with the biomass and woody volume as high as 447 Mg/ha and 493 m 3 /ha respectively. The dry season HV backscattering intensity was highly sensitive to the biomass and woody volume compared to the rainy season backscattering intensity. The SAR data acquired in rainy season with humid and wet canopies were not very sensitive to the in situ biomass and woody volume. The strong dependence of the biomass and woody volume estimates with the season of SAR data acquisition confirmed that the choice of right season SAR data is very important for improving the satellite based estimates of the biomass and woody volume. We expect that the results obtained in this research will contribute to monitoring of forest biomass and woody volume in Vietnam and abroad.
Fuel mix for various vessel types. HFO = Heavy Fuel Oil; MDO/MGO = Marine Diesel/Gas Oil; LSHFO = Low Sulfur Heavy Fuel Oil; LNG = Liquefied Natural Gas. From Smith, T., Raucci, C., Sabio, N., Argyros, D. (2014b). Global marine fuel trends 2030. Lloyds Register Marine; University College London Energy Institute, London.
CO 2 emissions in marine activity. Data from Olmer, N., Comer, B., Roy, B., Mao, X., Rutherford, D. (2017). Greenhouse gas emissions from global shipping, 2013-2015. The International Council on Clean Transportation (ICCT), Washington.
CO 2 emissions from different sources of marine transportation. Data from Smith, T., Raucci, C., Sabio, N., Argyros, D. (2014b). Global marine fuel trends 2030. Lloyds Register Marine; University College London Energy Institute, London.
Top five merchant fleets by nation.
This module article provides a broad-scoped overview of the current marine transportation industry and energy use within the sector. More specifically, it outlines and explains many facets of energy use within this complex marine transportation sector, including vessel engine-type, energy use profiles and influence of complexity on the sector’s energy profile overall. Marine transportation is responsible for 2-3% of global greenhouse (GHG) emissions and is predicted to increase to 17% by 2050 if left unchecked. As marine transportation continues to underpin 80-90% of global trade and consumption patterns, the energy use and energy profile of this industry becomes increasingly important to address and mitigate in the face of climate change.
Soil acidity has become a serious threat to crop production in most highlands of Ethiopia in general and in the western part of the country in particular. An earlier study estimated that about 41% of arable lands of Ethiopia are affected by soil acidity/Al 3+ toxicity. But recently the status of most soil in western Ethiopia were became acidic though the degree varied from location to location; severely limiting crop production. In western Ethiopia acidification occurs simultaneously with other conditions including eroded topsoil and depleted organic matter, depleted nutrients, and alternating drought stress and high rainfall which is high enough to leach appreciable amounts of exchangeable basic cations. In moisture-stressed areas, acidification can also be caused by continuous application of acid-forming chemical fertilizers. As low pH affects the availability of nutrients particularly that of phosphorus and other macronutrients, correction of the low pH through liming, and/or application of organic materials is critical for sustainable management of these soils. Agricultural liming is proved a good way of correcting soil pH along with supplying calcium to the soil. Another potential organic amendment sources in coffee producing areas of western Ethiopia were coffee pulp and husk, by products from wet and dry coffee processing respectively. These coffee by-products are utilized in other coffee producing countries as soil amendments especially in highly weathered soils. While in Western Ethiopia enormous quantities are either dumped into streams or burnt in big piles, with contributions to environmental hazards. Therefore, farmers should be encouraged to increase productivity of the acidic soils by using lime and organic amendments which is easily available such as composted coffee wastes (coffee husk and pulp).
Onne Stream Sediments (Dry Season)
Onne Stream Sediments (Wet Season)
This study assessed the seasonal variations in heavy metal concentration of stream sediments in parts of Onne, Rivers state Southeastern Nigeria. River Ogu was mapped for the collection of stream sediments because of its prominence as a receptor of a lot of effluents discharge from the NNPC oil refinery, erosion and weathering of heavy metals from nearby towns. Stream sediment samples were obtained from eleven (11) strategic locations at 3km interval and; a control sample was obtained from Akpajo river to cover both the dry and wet seasons. Samples were analyzed with Atomic Absorption spectrometric method (AAS) and X-ray fluorescence spectroscopy (XRF) for Ni, Cu, Hg, Pb, Zn,Cd, As and Cr. The record of the relative abundance of the heavy metals in the stream sediments in decreasing order for both seasons is as follows; Zinc (Zn) > Nickel (Ni) > Cadmium (Cd) > Copper (Cu) > Chromium (Cr) > Mercury (Hg) > Lead (Pb) > Arsenic (As). Higher mean concentration values were generally recorded in the wet season than in dry season. Four elements (Zn, Cd, Ni and Cu) were found to be far higher than tolerable standard of the Federal Ministry of Environment (FME, 2006). The sources of the heavy metals are attributed to Onne refinery, Onne waste dump, runoff from roadside soil, acidic precipitation and effluents from petrochemical industries. Excessive concentrations of heavy metals in the stream sediments affects the aquatic life of the faunas and floras and have adverse effect on humans and this calls for regular monitoring of the chemistry of stream sediments in the area.
Effective management of the groundwater resources became an important factor for the growth of urbanized areas, especially for the sector which has considerable agricultural and industrial activities. Along with quantity, assessment of the groundwater quality also plays an important role in its growth. Tandula watershed is one of the populated areas in the Balod district, Chhattisgarh state, which needs an assessment on the groundwater vulnerable zones for its effective management. The vulnerable zones of the study area have been assessed with the help of DRASTIC, DRASTIC-AHP, and modified DRASTIC-AHP methods. The models have been developed with the help of seven parameters which are depth to water, net recharge, aquifer media, soil media, topography, the impact of vadose zone, and hydraulic conductivity. The resulted groundwater pollution vulnerability in the study area has classified into five categories such as very low, low, moderate, high, and very high. Cross-comparison and validation of the model with 77 groundwater samples which contain Nitrate concentration were considered and concluded that the modified DRASTIC-AHP model is most accurate and suitable for the present study area. The study also revealed that groundwater in the study area is contaminated by Nitrate pollution due to excessive application of fertilizers in agricultural activities and improper sewage disposal.
Base map of the study area showing the VES points
Geological map of Akure and its environment [29]
VES data for Points 10 to 18
Summary of VES results
The study aims to integrate very low frequency electromagnetic method (VLF-EM) and vertical electrical sounding (VES) electrical resistivity methods to determine groundwater prospective in Ilara-Mokin, Akure. VLF profiling was carried out on eight traverses. VLF-EM profiling result showed areas which are relatively conductive with depth and VES stations were positioned based on the results of the VLF-EM survey. Eighteen VES were stationed with maximum electrode separation of 65m along six traverses trending East-West. A total of four geo-electric sections were generated in the N-S, WE , NE-SW and NW-SE directions revealing at most four geologic layers. The topsoil, clayey/lateritic layer, partially weathered to highly weathered layer and fresh bedrock have resistivity ranging from 105Ωm-445Ωm and a thickness of 0.5m-1.7m, 43Ωm-46Ωm and a thickness of about 6m, 200Ωm-811Ωm and a thickness of 0.5m-21.1m and 1122Ωm-6277Ωm respectively. The H, A, HA and AK curve types in the area revealed that the bedrock in the area is quite close to the surface. Also, the area is resistive as evident with the dominance of A curve type. VES points with H and HA curve types are likely groundwater prospects making the groundwater potential in the area to be rated as fair.
DRASTIC indexing and integrated electrical conductivity (IEC) modeling are approaches for assessing aquifer vulnerability to surface pollution. DRASTIC indexing is more common, but IEC modeling is faster and more cost-effective because it requires less data and fewer processing steps. This study aimed to compare DRASTIC indexing with IEC modeling to determine whether the latter is sufficient on its own. Both approaches are utilized to determine zones vulnerable to groundwater pollution in the Nile Delta. Hence, assessing the nature and degree of risk are important for realizing effective measures toward damage minimization. For DRASTIC indexing, hydrogeological factors such as depth to aquifer, recharge rate, aquifer media, soil permeability, topography, impact of the vadose zone, and hydraulic conductivity were combined in a geographical information system environment for assessing the aquifer vulnerability. For IEC modeling, DC resistivity data were collected from 36 surface sounding points to cover the entire area and used to estimate the IEC index. Additionally, the vulnerable zones identified by both approaches were tested using a local-scale resistivity survey in the form of 1D and 2D resistivity imaging to determine the permeable pathways in the vadose zone. A correlation of 0.82 was obtained between the DRASTIC indexing and IEC modeling results. For additional benefit, the obtained DRASTIC and IEC models were used together to develop a vulnerability map. This map showed a very high vulnerability zone, a high-vulnerability zone, and moderate- and low-vulnerability zones constituting 19.89, 41, 27, and 12%, respectively, of the study area. Identifying where groundwater is more vulnerable to pollution enables more effective protection and management of groundwater resources in vulnerable areas.
Spatial distribution of titanium (2.a), manganeses (2.b), iron (2.c), vanadium (2.d), zinc (2.e) and lead (2.f) Manganese (Mn) in stream sediments is relatively abundant with an average of 527.05 ppm, comparable with values reported by Mc Lennen and Taylor (1999) for upper crustal abundance. The content of Mn varies between (218.8 -1433 ppm). [5] The geochemical map of Mn (fig. 2.b) indicates high values in middle part of the basin in area with coal deposits that reflecting bedrock signatures. From this maximum point, the manganese concentration decreases concentrically to the south, where are present the sandy deposits and to the north where metamorphic and sedimentary rocks occurs.
This study examined the spatial relations of the selected metals in stream sediments tributary of the Oltet River in longitudinal profile, along the entire length (185 km) in relation to geology, lithology and anthropogenic activities. Differences in regional geology from the northern to the southern of the Oltet River Basin are reflected in stream sediment geochemistry. The Olteț River crossing crystalline formations belonging to the Danubian Domain represented by metamorphic rocks (schist, gneisses, mica-schiste) and the Pre-Alpine granite and granitoide massifs (Suşiţa, Tismana, Novaci, Cărpiniş type) associated (granitoide rocks are crossed by veins of microgranite, aplite, pegmatite and lamprophyre) of Upper Carboniferous, Permian and Mesozoic ages, followed by the Cenozoic formations belonging to the Dacian Basin. From the sequence of Cenozoic deposits, are remarkable the Pontian – Romanin deposits composed of clays, marnes, sands, that are characterized by the presence of lignite seams. Over Cenozoic deposits, in the midline and to the confluence with the Olt River zone, occurs the Quaternary formation (Lower, Middle and Upper Pleistocene). The Lower Pleistocene, rich in vertebrate fossils is composed by marnes, sands, gravels, with lenticular sandy-clay sequences and layers of coal. The Middle Pleistocene deposits are separated as sand-dusty deposits with high content of clays, whereas Upper Pleistocene is represented by the alluvial deposits (sands, gravels, clays) belonging to the Olt terrace. The type of methodology used in this study consists of geochemical sampling of stream sediments, mineralogical analysis, and quantitative determination of metals, GIS database and comparison of the stream sediments content with standards and levels recorded in the literature. Most metal concentrations can by spatially correlate to the regional geology, structural trends and the local effects of individual rocks units. Higher concentrations of vanadium, lead in stream sediments may have resulted from some anthropogenic activities. Activities that appear to have affected stream sediment include exploitation of the lignite in open pit and urban centers.
The water resource is one of the main bases for the economic development of such a country. In recent decades, this resource has experienced a qualitative and quantitative degradation under the effect of global warming, especially in zones under arid and semi-arid climate as the case of Morocco. A better understanding of the relationship between climate change and its impacts on the availability of water resources involves a climatological analysis (rainfall and temperature), a piezometric, hydrogeochemical, and isotopic approach. In this investigation, the area taken as an example is the Essaouira Basin. Trend analysis of rainfall and temperature series shows that rainfall and temperature show a downward trend of 12% and an upward trend of 0.9 (for the period 1950-2015) to 1.5 °C (for the period 1988-2004), respectively. The piezometric study shows a downward trend following the shortening of recharge periods and recurrent drought. The hydrogeochemical approach indicates a deterioration of groundwater quality with an increase in salinity. This degradation is due to the marine intrusion and to the decrease of the recharge rate of aquifers caused by the decrease of precipitations under the climate change effect. The isotopic approach shows that climate change has no effect on the isotopic content of the groundwater in the study area.
Morchella Galilaea Masaphy & Clowez 2012 true morals have been recorded in south India In Nilgiri Hills, Morchella research in South India has not taken place.worldwide fungus recorded 3.8 million species
Cross River State showing Ikom LGA source: Cross River State ministry of land and survey (2014)
Tsetse flies breeding space probability map
Land Use Land Cover Distribution of the study area
Tsetse flies probable breading space distribution
This paper examined the possible breading space of tsetse flies in Ikom Local Governement Area and it's environs in Cross River State, Nigeria, using remote sensing and geographic information system techniques. The study used supervised classification techniques with maximum likelihood algorithms to classify the satellite imagery in to four categories as vegetation-agriculture, water bodies, built-up lands, and other land uses and digitized all the rivers on the imagery as polylines. A buffer operation of 1km away from the digitized area was done; an overlaid analysis was carried out on the buffered operation and the classified image, so as to analyze the probability of breeding of the tsetse flies on each parcel of land. The study grouped the possible breeding sites of the tsetse flies into three; most probable, moderately probable and less probable breeding space. Result of the findings reveals that 48.496 Hectares (24.64 %) is most probable for tsetse flies to breed on, 107.54 hectares (54.24 %) is moderately probable, and 42.231 Hectares (21.3 %) is less probable. Based on the findings of the study it's apparent that Ikom Local Governement Area and it's environs provide a good breeding space and habitat for tsetse flies, it becomes imperative for all stakeholders in the control and eradication of tsetse flies, to work towards its total eradication in the area.
As climate change infiltrate and influence every sphere of the globe, the continuous study of the drainage features and assessment of the drainage basin as a fundamental geomorphic unit in water resources development and management cannot be relegated. This work has considered the analytical description of the physical division of RDCA. The three domains of the morphometric parameters (linear, areal, and relief aspects of the basin) were considered for the analysis. Remote sensing and GIS techniques were adopted in the analysis of the data using hydrological and surface tool in ArcGIS 10.2. The acquired SRTM DEM was used to delineate the catchment area and major morphometric parameters were estimated. The results show that the basin is elongated with low leminiscate ratio. RDCA is a 7 th order drainage basin, with an area of 11,355 km 2 , having a Original Research Article Gabriel et al.; JGEESI, 20(3): 1-13, 2019; Article no.JGEESI.48219 2 length of about 164 km 2. Value of drainage density indicates moderate runoff potentials. Stream frequency, bifurcation ratio and constant channel maintenance indicate medium permeability and that the basin produces a flatter peak of direct runoff for a longer duration. Channel encroachment, land use and land cover change seems the cause of perennial flooding in the region than change in drainage features. This study provides scientific database for further comprehensive hydrological investigation of RDCA around which Kashimbilla dam is located.
The main aim of the study, presented in this article was to precise the deep geological structure of joint zone between the Tien-Shan orogenics and Turan platform. Within this research we have determined the petrophysical features of the pre-Mesozoic sections of this zone. These data will help us in the further prospecting works for minerals searching. The principal method of study was the seismic-density modelling data complex interpretation, bonded to the geological and subsurface information from the previous works. The modeling was provided along the lines in the SouthWestern Gissar region, Uzbekistan. The main features, we paid attention, were rocks density, seismic wave velocity and magnetic features. As a result, deep geological structure and petrophysical features of different pre-Mesozoic formations of the study area were obtained.
Conceptual framework
Coding process (initial and axial)
This study investigated housing affordability in St Minver and Brambleside Community Land Trust, Cornwall, England. The methodology adopted was the qualitative methodology. The study addressed the potential barriers as well as the strategies adopted in the Community Land Trust (CLT) in the preservation of housing affordability. In-depth interviews were carried out on members of the community comprising both home owners and tenants. Findings revealed barriers such as the rigidity and overly stringent bureaucratic structures which oversee and regulate the program, and the desire of landowners to make profit, while CTL's strategies involve increased control over the resale of the houses and an emphasis on the purpose for its development for low-income earners. In conclusion it was stated that it is imperative to address these barriers in line with enabling quick decision making and ensuring the actual gains of the program are made available to its key targets
Wind energy is an important field of development for the island of Gotland, Sweden, especially since the island has set targets to generate 100% of its energy from renewable sources by 2025. Due to the variability of wind conditions, energy storage will be an important technology to facilitate the continued development of wind energy on Gotland and ensure a stable and secure supply of electricity. In this study, the feasibility of utilizing the Middle Cambrian Faludden sandstone reservoir on Gotland for Compressed Air Energy Storage (CAES) is assessed. Firstly, a characterization of the sandstone beneath Gotland is presented, which includes detailed maps of reservoir thickness and top reservoir structure. Analysis of this information shows that the properties of the Faludden sandstone and associated cap rock appear favorable for the application of CAES. Seven structural closures are identified below the eastern and southern parts of Gotland, which could potentially be utilized for CAES. Scoping estimates of the energy storage capacity and flow rate for these closures within the Faludden sandstone show that industrial scale CAES could be possible on Gotland.
In undersea gold mines, the development of a water-flow fracture zone and its connection with the aquifer may cause massive water and sand inrush disasters. In this study, approaches including theoretical analysis, numerical simulation and field detection are employed to identify the development height of the water-flow fracture zone caused by undersea mining in the Xinli Zone of the Sanshandao Gold Mine to ensure mining safety. An improved Winkler elastic foundation beam model, considering the coupled influences of seawater pressure and backfill support, was established to calculate the height of the water-flow fracture zone. The result demonstrates that the height of the water-flow fracture zone depends on the elastic modulus of the overburden strata and the compression modulus of the filling material. Then, an experimental study utilizing a custom-made apparatus is conducted to obtain the Winkler foundation compression characteristics of the filling material used in the gold mining operation. The theoretical analyses are confirmed by numerical simulations and show that the height of the water-flow fracture zone decreases with the increase in mining level because the loads from overburden weight decreases with the mining depth. The theoretical analysis, numerical simulation and field detection present that the height of the mining-induced water-flow fracture zone is 39 m, 37 m, and 40.5–45 m, respectively, after mining at the − 135 m level. These values are reasonably consistent, suggesting that the proposed theoretical and numerical models and the utilized field detection method can provide valuable information for determining the overburden stability of an undersea mineral seam and improving mining safety.
In this study the adsorption behavior of reed tissues has been investigated in a batch system in order to determine its applicability in treating wastewater. The optimum conditions for the treatment process were investigated by observing the influence of organ of plant (leaf, stem, root), pH levels, the presence of competing ions, initial concentration and of the reed tissues. The results indicated that the adsorption capacity was strongly affected by the initial concentration, pH levels and organ of plant. Optimum adsorption of Pb (II) was observed at pH 7.0, initial Pb(II) concentration 20 mg/L, temperature 25-45 0 C and contact time 30 minute. It has a good fit for the Freundlich compared with Langmuir isotherm models. As well as, Pseudo second-order kinetic model was fit better than pseudo first order model. Phragmites Australia shows that it is feasible for this plant material as a novel adsorbent for Pb(II) removal in the future.
Geological map of the Prohorovo area of the Sveti Ilija heights (modified after Čatalov, 1985)
Hydraulically brecciated dyke, (under the hammer) and serrated dolomitic contact of the dyke on the right side of the pictures
Principal stress orientations from 10 faults measured in the Tasladja Bair's quarry. The faults are striking in the NW quadrant. The axis of the maximum principal stress is plunging to W-SW. The calculations are made with FaultKin
Description of the hydrothermal alteration of the dykes from the Tasladja Bair
The Prohorovo pluton is intruded in a complex geological environment in the southeastern part of the Sveti Ilija ridge, municipality of Nova Zagora, Sliven district. This magmatic body is of interest, because it is related to a copper-molybdenum, vein-porphyry mineralisation. The pluton occupies a hypabyssal intrusion level, as the intrusion of the main magmatic body, as well as the smaller sub-intrusions are controlled by two fault systems striking to northeast and northwest. During the eighties and nineties of the last century, there were efforts to study the faults in the vicinity of the pluton and an agreement was reached, that they determine the geometry of the hydrothermal system. However, there are still unsolved issues regarding the degree to which the faults control the intrusion of the igneous bodies, screen the hydrothermal fluids or create fractured environment favourable for mineral deposition. So far, it is not clear if the ore hosting fractures are product of the faults or of the sub-intrusive process itself, which can also lead to fracturing of the host rocks. Several NE striking dykes have been recently exposed in a dolomitic quarry, in the locality of Tasladja bair, which is adjacent to the Prohorovo pluton. The dykes were hydrothermally altered and hydraulically brecciated. A fault slip analysis reveals that the faults, the pluton and the dykes were created by the same stress field. It confirms the assumption that the dykes are synchronous to the metal bearing hydrothermal mineralisation and offer an opportunity to model the intrusion of the pluton in a straightforward manner using the geometry of the faults, which controlled it.
Plant parasitic nematodes are very important pests, causing serious damage for various crops in general and citrus in particular. In this study, the main soil properties and composition of plant parasitic nematodes in citrus growing gardens in Cao Phong (Hoa Binh) were determined. The results showed that the soil characteristies are suitable for the citrus growth. Also, nine species of plant parasitic nematodes belonging to eight genus, six families and two orders associated on citrus were identified. Of which, the density and frequecy of Tylenchulus, Helicotylenchus, Rotylenchulus, Pratylenchus were larger in this survey. The number and composition of plant parasitic nematodes were directly related to the history of citrus cultivation and seeds as well as irrigation. Tylenchulus semipenetrans is considered as one of the main pests in Cao Phong citrus growing rhizosphere with the highest number of plant parasitic nematodes accounted for 96,34%.
Evaluation of heavy metals is essential to monitoring of soil pollution, maintain the quality of the environment and human health. The aims of this study to assess concentrations of heavy metals in Bandar-e-Imam and Deylam coastal sediments. The data collected during 2015, in 20 stations, 43 samples were collected from coastal sediments and heavy metals were analyzed by ICP-MS and atomic absorption. Then, statistical parameters and important geoenvironmental index such as geo-accumulation index(Igeo), Enrichment factor (EF), contamination factor(Cf), degree of contamination(Cd), Pollution load index(Pli) and ecological risk index(Er) was calculated and for the best distribution we used inverse distance weighting interpolation (IDW) and radial basis function (RBF) with five sub-branch of the local polynomial method (LP) and global (GP). Based on the results of the chemical analysis the average of the chromium, mercury, arsenic, lead, and cadmium is 54.27, 0.07, 5.49, 10.13 and 0.25 mg/kg respectively. Following the concentration of heavy metals is compared with similar studies in the world. The study area has a heavy manufacturing industry and harbor position, so heavy metal pollution showed a dominant performance of anthropogenic activities and in comparison, risk of contamination in the Bandar-e- Imam is higher than the Deylam shoreline.
Located on the flank of Ngozi volcanoes (Tanzania), the Shiwaga gas field is a spot of intense CO2( g) emanations. Physicochemical measurements on different types of waters (rivers, puddles, and springs) as water and gas sampling were discontinuously performed over 10 years for equilibrated partial CO2 pressure calculations and stable isotopic analyses. The most striking result shows that meteoric H2O and deep originated CO2( g) exchanges are responsible for a negative 18O-shift of the studied waters in relation with waters electrical conductivity, pH, and pCO2eq changes. In spring waters, a maximum shift of − 11.2‰ in δ18O was observed and pCO2eq values up to 1196 mbar were computed. Although this trend has already been reported around the world, such extended shift is rarely measured and requires an important amount of CO2( g), with a CO2( g)/ H2O ratio up more than 0.5 mol/mol. This approach is useful to better understand the hydro-geochemical processes involved in such environments. Moreover, this study evidences that an inventory as a monitoring of these gas fields are needed for the management of natural hazards and local resources.
Microbial-induced calcium carbonate precipitation (MICP) is a sustainable technique to transform or improve physical and mechanical properties of soils. This paper aims to study the effect of activated carbon (AC) on the property of bio-treated China Standard sand. Six sample groups were prepared considering various dosages of cementation solutions and bacterial suspensions. In each group, samples were prepared at six different AC ratios (0%, 0.2%, 0.5%, 1%, 2%, and 3% by weight of sand). Bacterial retention ability, calcium carbonate mass, unconfined compression strength (UCS), and microstructures of bio-treated samples were examined and evaluated in the presence of AC. It was found that the improved yield of calcium carbonate crystals and increased UCS were correlated to the enhanced bacterial retention ability attributed to AC. In addition, the test results showed that the amount of cementation solution played an important role in the MICP process, but volume variation of the bacterial suspension had a little effect on the bio-treated samples.
The analytical hierarchy process (AHP) is one of the most effective methods for criteria ranking/weighting to have been successfully incorporated into GIS analyses. We present a new method for optimizing pairwise comparison decision-making matrices in AHP method, which has been developed on the basis of an interval pairwise comparison matrix (IPCM) derived from expert knowledge. The method has been used for criteria ranking in land subsidence susceptibility mapping (LSSM) as a practical test case, for which an interval matrix was generated by pairwise comparison. To compare the capability of the AHP method (a traditional approach) with that of the proposed IPCM method (a novel approach), 11 creations of LSSM were ranked using each approach in turn. The criteria weightings obtained were then used to produce LSSM maps based on each of these approaches. The results were tested against a data set of known land subsidence occurrences, indicating an improvement in accuracy of about 14% in the LSSM map that was developed using the IPCM method. This improvement was achieved by minimizing the uncertainty associated with criteria ranking/weighting in a traditional AHP and could form a basis for future research into minimizing the uncertainty in weightings derived using the AHP method. Our results will be of considerable importance for researchers involved in GIS-based multi-criteria decision analysis (MCDA) and those dealing with GIS-based spatial decision-making methods.
Groundwater constitutes the major source of utility water in Ekiti State with the majority of the population depending on groundwater for drinking and other household uses. Soil in the area is commonly used as a component of building materials, which may produce radon in the indoor environment. Excessive concentrations of radon in water and soil can cause radiological health risks to human as witnessed by the increased cases of lung cancer among non-smokers in Nigeria, which may be traceable to the ingestion and inhalation 222Rn in drinking water and indoor air. In the present study, comparative in situ measurements of radon in groundwater and soil gas were carried out at one hundred selected locations across the Ekiti State in southwest Nigeria, using a RAD7 radon detector to generate a radon distribution map and to estimate radiation hazards due to radon. The concentrations of radon in groundwater ranged from 0.9 to 472 Bq L− 1 with a mean of 34.7 ± 4.4 Bq L− 1, while those of soil gas ranged from 0.1 to 315 kBq L− 1 with a mean of 38.9 ± 1.4 kBq L− 1. The total annual effective dose due to inhalation and ingestion of radon in groundwater amounted to 94.7 μSv year− 1, which is lower than the reference dose of 100 μSv year− 1 recommended by the World Health Organization (WHO). The radon map generated for groundwater and soil gas identified three distinct areas with radon levels ranging from low to high. The results of this study show that some locations (Emure, Gbonyin, Ijero and Ikole) show mean total annual effective doses which are higher than the recommended limit. It can then be inferred that the groundwater samples pose significant radiological hazards to the population and that the noticed increase in lung cancer cases may be attributed to the consumption of groundwater in the area.
This study has enabled the lithological units intersected by a well, locate contacts of adjacent beds, locate depth to groundwater and determine the thickness of the units. Records of three geophysical logs parameters; resistivity, gamma ray and self-potential (SP) measured in five boreholes which were drilled as part of a Rural Water Supply Project Phase II in the Juabeso-Bia District were correlated with the geological logs on site from the drill cuttings of the bore hole. The boreholes depths were between 45-52m and were drilled over hornblende, phyllites and granites which constitute part of the various rock types of the Birimian system. Deflections of the SP logs established the presence of permeable rock formations. Alternatively, the long-short-normal logs distinguished between permeable and impermeable beds by recording lower or higher apparent resistivity signals respectively on the log sheet. These anomalies are identified mostly in the weathered zones and also within the fresh rocks. In almost all the boreholes the gamma ray logs indicated low clay content which may be due to the absence of intensely weathered rocks or low concentration of radioactive rocks within the survey area. The application of gamma ray logs rely on the fact that the concentrations of radioactive isotopes varies from one rock type to another and that acidic rocks are more radioactive than the basaltic rocks hence most of the rocks in the project area is more basaltic. Though the SP deflection was able to indicate permeable formations there was no guarantee that the rock formation could contain water. However, the combined interpretation of the three other logs shows that deflections of SP close to the basement rocks and lower resistivity values on the long-short-normal logs generally indicated the presence of water bearing formations. Three lithological units were identified over the various rock types: a top layer predominantly clay of thickness between 0-25m overlying a weathered zone about 16-45m thick above the fresh rocks of the various types.
Dig pitches in parts of Bugai town by illegal miners
2D Resistivity models along profiles A-E
Rocks samples collected for geo-chemical analysis
The aim of the present research is to provide an update of gold deposits models scattered in Bugai Village Birnin – Gwari Local Government Area of Kaduna State, through identifying basic geologic structures which act as host to mineralization, delineate zones of gold distributions and to map the spread and extend of the gold mineralization. Electrical resistivity method using the dipole-dipole array was applied and ten (10) parallel 2D profile data were collected manually each of length one hundred meters (100 m,) separated by ten meters (10 m)and with minimum electrode spacing of three meters (3 m). The 2-D data were processedinto 3-D data using RES2DINV computer inversion software for effective and accurateinterpretation of the location for the gold deposit. Results from both 2D and 3D resistivitymodels show a variation in shape due to heterogeneous nature of mineralization within thestudy area at different depths. The mineralization within zones of elevated resistivitycomprises of silification and quartz veining which is structurally controlled and follow a N-W and NE-SW orientations. The high resistivity anomalies at depth greater than five meters, (5m)with well-defined patterns observed in the 3D resistivity model are related to themineralization of gold bearing quartz veins. Geochemical analysis of rock samples collectedat depth of five meters (5m) which shows 124.79 and 1.77 concentration in ppm for gold andsilver corroborated the result of the geo-electrical data. This research shows that electricalresistivity techniques can be applied to map the large scale stratigraphy and structure in whicha gold deposit might be located.
The movement of point M within the time interval t0 – t1 (s) is specified by the law x=x(t); y=y(t). The trajectory and the position of point M on it is determined for the moment of time t= t1 (s). The radial and transverse components of the velocity and acceleration of the point are represented in a matrix form and all the kinematics characteristics of the movement are graphically depicted. The classical kinematics problem for a point moving in the plane Oxy is solved with the MathCAD package. Usually, the motion law of the point is set within the coordinate form and its kinematic characteristics are determined for a certain point in time. In the example examined, the point moves in accordance with the known trajectory f(x, y)=0 and motion law s=s(t). The position of point M for the moment of time t=t1 as well as the dependencies y=y(x); s=s(t); aƬ= aƬ(t); an= an(t); a= a(t) are graphically defined. re.
A common global practice in the High Atlas Mountains is upstream water storage in dammed reservoirs that captures mountainous snowmelt, and downstream agriculture irrigation. However, the intensive use of water for irrigation, coupled with the effects of climate change, makes the region subject to high water stress. This implies the establishment of an integrated management system adapted to such water resources. Effective management of groundwater requires good control upstream of the different sources of supply and their contribution. Thus, we conducted a study on the contribution of the components snow and rain recharge of surface water and groundwater in the High Atlas, using chemical and isotope investigations. The isotopic results from the 2 sites upstream catchments (Souss and Tensift) compared to those obtained in the Draa basin highlight the importance of spatial and temporal variabilities of isotopic signal, which may impact quantifying the contributions of snowmelt to stream flow and groundwater. Using the stable isotope mixing model, the contribution of runoff derived from snowmelt (SN) ranges between 42 and 75% in the headwaters of the studied catchments, while the component of rainfall is 25–58%. The low mineralized waters from the High Atlas induce a dilution of the water salinity in the neighboring plains (Souss, Tensift and Draa). The results could be used to help refining hydrological conceptual models at various scales.
Top-cited authors
Virendra Kumar Saxena
  • National Geophysical Research Institute
Michael A Powell
  • University of Alberta
Veeresh Hogarnal
  • University of Agricultural Sciences, Raichur
Brian R. Hart
  • The University of Western Ontario
NC Mondal
  • CSIR-National Geophysical Research Institute