Spatial Variability Of Groundwater Quality Research Articles

Spatial variability of groundwater quality and its suitability for drinking and irrigation in the Amik Plain (South Turkey)

In this study, it is determined physicochemical properties of the groundwater and the spatial variability of physicochemical properties of the groundwater in the Amik plain and as well as assess its suitability for drinking and irrigation. A total 92 groundwater samples were collected from drilled well in June 2012. In addition, the 42 of 92 drilled wells were also sampled in September 2012 to evaluate the changes of groundwater properties. According to t test values, the mean Ca2+, SO4 2−, Mg2+ and TH values in the June period were significantly lower than those of the September period. On the other hand, the mean (CO 3 2− + HCO3 −) and RSC and MR values in the June period were significantly higher than those of the September period. The order of relative abundance of major cations in the groundwater (in mg L−1) is in order Na+ > Mg2+ > Ca2+ > K+. The order of the anions abundance (mg L−1) is SO4 2− > Cl− > HCO3 − > CO3 2− in this research. Log and square-root transformation were carried out for the most of the water properties before the calculation of semivariance. The nugget ratio showed all the variables were strongly spatial dependent except for K+ and Mg2+ and (CO3 2− + HCO3 −) which showed moderate spatial dependence (ratio ranging from 28 to 49.9 %). Spatial distribution analysis of groundwater quality indicated that The EC, TDS values and Na and Cl− contents which is important water quality parameters increase from northern towards southern. The total hardness values increase also from northwestern towards southwestern.

GIS applicability to assess spatio-temporal variation of groundwater quality and sustainable use for irrigation

Sustainable and safe use of groundwater requires periodical monitoring of its quality. Because of the presence of multiple contaminants, spatial variation of overall groundwater quality is difficult to describe. The present study describes the overall groundwater quality for irrigation using a multi-criteria quality assessment system and sustainability of water use by incorporating the aspect of temporal variation of groundwater quality. The GIS-based multi-criteria system effectively amalgamated different quality parameters into an easily understandable format and assessed the spatial variation of groundwater quality for irrigation in west Delhi, India. The rate of spatial increment of poor quality groundwater within the study period was 3.7 km2 per year. It has been observed that there is deterioration of groundwater quality from southwest to east, along the general groundwater flow direction, and improvement of groundwater quality from west to northeast, due to less urbanization and availability of groundwater recharge zones with good quality water. Temporal variation of groundwater quality is high (V > 20 %) at northern part, moderate (V = 10–20 %) at middle and southern parts, and less (V < 10 %) at some pockets of southern part of the study area. The overall groundwater quality coupled with its variation reveals that while the groundwater use is mostly unsustainable in the southern part, groundwater sustainability is constrained by relatively poor and variable quality in western and northern fringes of the study area.

Suitability assessment of deep groundwater for drinking, irrigation and industrial purposes in Jiaozuo City, Henan Province, north China

Groundwater has been a major natural resource for human consumption in north China. It is necessary to appreciate the suitability of deep groundwater for drinking, agricultural irrigation, and industrial uses in this region. To this end, a total of 47 groundwater samples were collected from the study area; by comparing the concentrations of different hydrochemical variables with quality standard values, the variable fuzzy set (VFS) was applied to calculate the groundwater quality index (GQI) for various purposes, respectively. Afterward GQI spatial distribution maps were constructed using a geographic information system (GIS) tool to delineate spatial variations of groundwater quality. In this case study, the GQI spatial distribution maps reveal that the areas covered by “Maximum Permissible” groundwater for varying purposes (drinking, irrigation, and industrial) is 1377.2; 2354.7; and 3854.8 km2, respectively. The groundwater in the eastern part of the study area is suitable for drinking, with the southwestern region as the irrigation water source; the entire study area is acceptable for use in industrial, except the western part of Jiaozuo City. Therefore, the GQI spatial distribution maps can provide useful information for non-technical decision makers for better sustainable groundwater resources management.

Hydrogeological characterization and assessment of groundwater quality in shallow aquifers in vicinity of Najafgarh drain of NCT Delhi

Najafgarh drain is the biggest drain in Delhi and contributes about 60% of the total wastewater that gets discharged from Delhi into river Yamuna. The drain traverses a length of 51 km before joining river Yamuna, and is unlined for about 31 km along its initial stretch. In recent times, efforts have been made for limited withdrawal of groundwater from shallow aquifers in close vicinity of Najafgarh drain coupled with artificial recharge of groundwater. In this perspective, assessment of groundwater quality in shallow aquifers in vicinity of the Najafgarh drain of Delhi and hydrogeological characterization of adjacent areas were done. The groundwater quality was examined in perspective of Indian as well as World Health Organization’s drinking water standards. The spatial variation in groundwater quality was studied. The linkages between trace element occurrence and hydrochemical facies variation were also established. The shallow groundwater along Najafgarh drain is contaminated in stretches and the area is not suitable for large-scale groundwater development for drinking water purposes.

Hydro-Chemical Facies Water Sources. The Region Rabat-Sale-Zemmour-Zaer of Morocco

A sampling network of fifty-one (51) samples of water sources has been chosen as a geographic and habitat significant enough to afford to acquire representative data on the spatial variability of groundwater quality of the Rabat-Sale-Zemmour-Zaer. This network consists of three groups of water areas and covers almost the entire study site. With the help of the method of Piper diagram, the waters of different origins are easily differentiated

Evaluation of spatio-temporal trends of groundwater quality in different land uses using Kendall test

The monitoring of temporal and spatial variations of groundwater quality is important for better managing groundwater resources. In a heavily cultivated agricultural site, Yupori, Chuncheon (Korea), groundwater quality has been monitored since 2002 because the groundwater in this area contains elevated levels of nitrate. Concentrations of NO3-N, SO42−, and Cl− were found to be high in vegetable fields and low in fruit orchards. For groundwater management purposes, a regional Kendall test was carried out to investigate the spatio-temporal trends of three major anion (NO3−N, SO42−, and Cl−) concentrations for various land use types: vegetable fields, fruit fields, and barns. The mean concentration of NO3-N in the vegetable fields exceeded the maximum contaminant level for drinking water (10 mg L−1) and showed the highest increasing trend with time among the various land use types. The results showed a statistically significant increasing trend in the NO3-N and SO42− concentration in vegetable fields from 2002 to 2007. The estimated slope of the NO3-N and SO42− concentration in the vegetable fields was 2.1 mg L−1 per year and 1.01 mg L−1 per year over a period of 6 years. The concentration of Cl− showed an increasing tendency in fruit fields and decreasing tendency in barns. In order to regulate groundwater quality in the study area, nitrate contamination in vegetable fields should be particularly controlled. Spatio-temporal trends for different land uses using regional Kendall test can be usefully applied to control groundwater quality in the study area.

A geoelectrical and hydrogeological study for the assessment of groundwater resources in Wadi Al Bih, UAE

Drilling information, historical water table levels, groundwater salinity records of the existing water wells in Wadi Al Bih area, United Arab Emirates, were stored in a geodatabase and used to characterize the geological and hydrogeological settings of this area. A 2D earth resistivity imaging survey was conducted for the first time in the Northern UAE to determine the potential of the Quaternary aquifer and its groundwater quality in the areas where there are no monitoring wells. The results of the chemical analyses of the collected groundwater samples together with the inversion results of the resistivity data were used to draw a total salinity map and determine the spatial variations in groundwater quality. The inversion results of the 2D earth resistivity imaging data indicated that the Quaternary aquifer in the study area is in a good connection with the underlying carbonate aquifer. It also indicated that the carbonate aquifer is of major regional and vertical extension and it contains the fresh water in this area. The data stored in the developed database were used to produce different types of geopotential maps.

Evaluation of spatial variations in groundwater quality by WQI and GIS technique: a case study of Virudunagar District, Tamil Nadu, India

Groundwater plays a major life support to mankind. It is the major source to meet the domestic, irrigation and industrial water demands. The depletion of groundwater through excessive consumption and less recharge in the study area has detoriated the quality of groundwater. The present study has analyzed the pre- and post-monsoon physicochemical data of groundwater samples from 49 different bore wells in Virudunagar district. Spatial distribution maps were prepared for various physicochemical parameters using geographic information system. These maps are further classified according to highest desirable, maximum permissible and not permissible prescribed by the World Health Organization. Furthermore, a water quality index (WQI) map was also generated to understand the groundwater quality in the study area. It was observed that the groundwater in the area is hard and alkaline in nature and the WQI reveals that most part of the study area fall under fair water quality class. Also, the effect of recharge during monsoon period has diluted the geochemistry of the groundwater. The application of GIS and WQI in the study area is a promising tool to understand the spatial pattern of groundwater quality and its management.

Hydro-geochemical processes in an area with saline groundwater in lower Shire River valley, Malawi: An integrated application of hierarchical cluster and principal component analyses

Abstract Our ability to adapt to changes in groundwater quality, arising from a changing climate and/or local pressures, is dependent on comprehension of the governing controls of spatial variation in groundwater chemistry. This paper presents results of an assessment of dominant hydro-geochemical processes controlling groundwater chemical composition, using an integrated application of hierarchical cluster analysis (HCA) and principal component analysis (PCA) of a major ion dataset of groundwater from lower Shire River valley, Malawi. The area is in the southernmost part of the western section of the East African Rift System (EARS) and has localised occurrence of saline groundwater. HCA classified samples into three main clusters (C1–C3) according to their dominant chemical composition: C1 (dominant composition: Na–Cl; median TDS: 3436 mg L −1 ), C2 (dominant composition: Na–HCO 3 ; median TDS: 966 mg L −1 ) and C3 (dominant composition: alkali earths–HCO 3 ; median TDS: 528 mg L −1 ). These clusters were in turn described by the principal components PC1, PC3 and PC2, respectively, resulting from the PCA. The results of the PCA and geochemical interpretation suggest that the spatial variation of groundwater quality in the area is influenced by the following processes: C3 samples result mainly from H 2 CO 3 weathering of aluminosilicate minerals by percolating water supersaturated with CO 2 . In addition to aluminosilicate weathering, C2 samples are influenced by the processes of cation exchange of Ca 2+ and Mg 2+ in the water for Na + on clay minerals, and carbonate precipitation. The increase in ionic strength of C2 samples is attributed to mixing with high TDS groundwater in proximity with C2 samples. The saline/brackish C1 groundwater results from the processes of evaporation (for samples with high water table close to the Shire marshes) and dissolution of Cl − and SO 4 -evaporative salts followed by mineralised seep from sedimentary Karoo and Cretaceous Lupata sandstones.

Assessment of Spatial Variation of Groundwater Quality and Its Relationship With Land Use in Perth Metropolitan

To determine the effects of land use on groundwater quality in Western Australia, a quantitative analysis is carried out using groundwater quality data supplied by the Department of Water from over 500 groundwater wells across the Perth metropolitan area. We analyzed four main groundwater quality indicators; nutrients, physical parameters, inorganic non metals and trace metals. We found that groundwater beneath agricultural land was found to be particularly susceptible to nutrient loading due to the application of fertilizers. Nutrient levels were found to be rising over time due to increasing agriculture and urban development. Industrial areas were also found to have numerous contamination plumes that continue to migrate with the groundwater flow. According to Australian and New Zealand Environment and Conservation Council (ANZECC) guidelines and the Australian Drinking Water Guidelines (ADWG), several areas including rural areas like Carabooda lake, Gnangara and Jandakot Mounds, Cockburn Sound, Forrestdale, Joondalup, and Ellenbrook and high density urban areas like Balcatta and Neerabup, industrial areas like North Fremantle, Welshpool and Kwinana are indentified as the vulnerable areas for groundwater quality.

Seasonal and spatial variation in groundwater quality along the hillslope of an agricultural research catchment (Western France)

AbstractShallow groundwater that develops on hillslopes is the main compartment in headwater catchments for flow and solute transport to rivers. Although spatial and temporal variations in its chemical composition are reported in the literature, there is no coherent description of the way these variations are organized, nor is there an accepted conceptual model for the mechanism involved. On the basis of the results from an experimental hillslope, we propose a description of the variation in spatial and temporal patterns of groundwater chemical composition and discuss the mechanisms involved. We instrumented a headwater catchment with a network of 42 nested piezometers along a 200 m hillslope and monitored major anion composition frequently over a 2‐year period. The results demonstrated that (i) the anionic composition in water table fluctuation zone varied significantly compared to deeper portions of the aquifer on the hillslope, confirming that this layer constitutes a main compartment for the mixing of new recharge water and old groundwater, (ii) deeper parts of the aquifer exhibited seasonal variations with structured hysteretic patterns, suggesting that mixing processes also occurred at greater depths and (iii) these hysteretic patterns were dampered from upslope to downslope, indicating an increased influence of lateral flow downslope. We recommend that the generality of these observations be assessed in different environments, as they can constitute a new set of processes to include in hydrological models. Copyright © 2010 John Wiley &amp; Sons, Ltd.

Groundwater quality assessment of Dhanbad district, Jharkhand, India

Groundwater quality assessment is important to ensure sustainable safe use of water. However describing the overall water quality in the Dhanbad coal mining area of India is difficult due to the spatial variability of multiple contaminants and wide range of indicators that could be measured. An attempt has been made to study the spatial variation of groundwater quality based on an integrated analysis of physico-chemical parameters and use of Geographic Information System (GIS). Using GIS contouring methods with Arcview 3.2a, spatial distribution maps of Hardness, pH, TDS, HCO3, SO4, NO3, Ca, Mg, Cl, and F have been created. From the Water Quality Index map it is inferred that despite the mining and heavy industry, the quality of water is predominantly good to excellent.

Spatial Variability of Groundwater Quality and its Relationship with Pistachio Yield in Anar Region, Iran

Spatial Variability of Groundwater Quality and its Relationship with Pistachio Yield in Anar Region, Iran

Urbanization and its impact on groundwater: a remote sensing and GIS-based assessment approach

The perils of unplanned urbanization and increasing pressure of human activities on hydro-geomorphologic system often result in modification of the existing recharge mechanism, which leads to many environmental consequences. In the present research, an attempt has been made to investigate the applicability of remote sensing and geographical information system (GIS) in dealing with spatial and temporal variability of dynamic phenomena, like urbanization and its impact on groundwater. This paper covers primarily, quantitative and qualitative impacts of urban growth on the behavior of aquifer in Ajmer city (India). Urban growth of the Ajmer city in last 17 years has been estimated from the satellite images. Database related to urbanization and groundwater has been created in GIS. Groundwater recharge has been computed using a water balance approach known as Water Level Fluctuation Methodology. Recharge estimation methodology has been implemented in GIS to introduce the spatial variability of hydro-geological characteristics. Further, temporal and spatial variations in groundwater quality and quantity have been correlated with urban growth using overlay analysis in GIS. The study reveals a general decline in water table and quality with urbanization. Further, remote sensing and GIS technologies have been found useful in assessment of spatial and temporal phenomena of urbanization and its impact on groundwater system.

Observations on elemental concentrations of groundwater in central Benin

ICP-MS; ICP-OES; Africa; Benin; Regional characterization Summary Groundwater samples were collected at over 100 locations in Benin, West Africa, for the purpose of characterizing region-wide spatial variation in groundwater quality as indicated by concentrations of a number of elements measured within the samples. Analytic techniques ranged from field measures of conductivity and pH, to characterization of major and trace element concentrations using ICP-MS and ICP-OES. Five methods of data analysis were applied to the resulting data set: indicator variables, parameter plots, cluster analysis, variogram analysis, and principal component analysis (PCA). A number of observations are developed from these analyses including regional trends in concentrations and variation of concentration of major and trace elements in specific geologic settings. Perhaps most significant is the identification of a region in the southern portion of the study area where the element chemistry shows high spatial variability. This region had not been identified in prior studies of the regional geochemistry. The mechanisms leading to this variability remain under study. The results presented provide significant insight into the regional variation in groundwater elemental chemistry for Benin. Further, they provide further illustration of the utility of applying multiple data analysis techniques to assessment of regional water quality data sets. a 2007 Elsevier B.V. All rights reserved.

Assessing groundwater quality using GIS

Assessing the quality of groundwater is important to ensure sustainable safe use of these resources. However, describing the overall water quality condition is difficult due to the spatial variability of multiple contaminants and the wide range of indicators (chemical, physical and biological) that could be measured. This contribution proposes a GIS-based groundwater quality index (GQI) which synthesizes different available water quality data (e.g., Cl−, Na+, Ca2+) by indexing them numerically relative to the World Health Organization (WHO) standards. Also, introduces an objective procedure to select the optimum parameters to compute the GQI, incorporates the aspect of temporal variation to address the degree of water use sustainability and tests the sensitivity of the proposed model. The GQI indicated that the groundwater quality in the Nasuno basin, Tochigi Prefecture, Japan, is generally high (GQI <90). It has also displayed the natural (depth to groundwater table, geomorphologic structures) and/or anthropogenic (land-use and population density) controls over the spatial variability of groundwater quality in the basin. Temporally, groundwater quality is more variable in the upper and lower parts of the basin (variation, V, 15–30%) compared to the middle part (V, <15%) probably attributed to the seasonality of precipitation and irrigation of rice. In the lower southeastern part of the Nasuno basin and the vicinity of the Naka and Houki rivers the sustainable use of groundwater is constrained by the relatively low and variable groundwater quality. The model sensitivity analysis indicated that parameters which reflect relatively lower water quality (high mean rank value) and those of significant spatial variability imply larger impacts on the GQI and must be carefully and accurately mapped. Optimum index factor technique allows the selection of the best combination of parameters dictating the variability of groundwater quality and enables an objective and fair representation of the overall groundwater quality.

Characterizing the spatial variability of groundwater quality using the entropy theory: II. Case study from Gaza Strip

AbstractThis paper, the second in the series, uses the entropy theory to describe the spatial variability of groundwater quality data sets. The application of the entropy theory is illustrated using the chloride observations obtained from a network of groundwater quality monitoring wells in the Gaza Strip, Palestine. The application involves calculating information measures, such as transinformation, the information transfer index and the correlation coefficient. These measures are calculated using a discrete approach, in which contingency tables are used. An exponential decay fitting approach was applied to the discrete models. The analysis shows that transinformation, as a function of distance, can be represented by the exponential decay curve. It also indicates that, for the data used in this study, the transinformation model is superior to the correlation model for characterizing the spatial variability. Copyright © 2004 John Wiley &amp; Sons, Ltd.