Groundwater Management Plan Research Articles

Delineation of Groundwater potential zone using Geospatial and AHP techniques in Ken River Basin (KRB) in Central India

Groundwater is the most salient and utilitarian water resource for living organisms. However, major parts of the Ken River Basin (KRB) in Central India are grappling with the overexploitation of groundwater resources, primarily due to extensive agricultural activities, raising problems in achieving Sustainable Development Goals (SDGs) 2 and 6. This study focused on delineating groundwater potential zones (GPZ) by employing remote sensing and GIS-based thematic datasets, complemented by the application of the Analytic Hierarchy Process (AHP). The thematic layers consisting of geomorphology, precipitation, geology, soil texture, lineament density, slope, LULC, and drainage density were considered and further weights were allocated with respect to their water storing capacity and characteristics to groundwater occurrences to develop GPZs. The zones were generated by classifying overlayed maps into four categories namely, very low, low, moderate, and high. The key findings indicated that 13.84%, 62.34%, 23.37%, and 45% of areas were found under high, moderate, low, and very low GPZs respectively. Furthermore, the zonation map was validated with 48 boreholes’ yield, which revealed a noteworthy 77.08% borewells in concurrence with predicted zones. Area Under the Receiver Operating Characteristic (AUROC) curve showcased a commendable 70.1% accuracy using the ROC curve. These results were highly beneficial in formulating sustainable groundwater management plans and policies, contributing towards the attainment of targets outlined in SDGs 2 and 6, particularly in regions resembling the KRB.

Toward field-scale groundwater pumping and improved groundwater management using remote sensing and climate data

Groundwater overdraft in the western United States has prompted water managers to develop groundwater management plans that include mandatory reporting of groundwater pumping (GP). However, most irrigation systems in this region are not equipped with irrigation water flow meters to record GP and performing quality control of the available metered GP data is difficult due to the scarcity of reliable secondary GP estimates. We hypothesize that Landsat-based actual evapotranspiration (ET) estimates from OpenET can be used to predict GP and aid in quality control of the metered GP data. The objectives of this study are to: 1) pair OpenET estimates of consumptive use (Net ET, i.e., actual ET less effective precipitation) and metered annual GP data from Diamond Valley, Nevada, and Harney Basin, Oregon; 2) evaluate linear regression and machine learning models to establish the GP vs Net ET relationship; and 3) compare GP estimates at the field- and basin-scales. Results from using a bootstrapping technique showed that the mean absolute errors and root mean square errors for field-scale GP depth are ∼11 % and ∼14 % across Diamond Valley and Harney Basin based on the OpenET ensemble mean, which showed the highest skill among all the OpenET ET models. Moreover, the regression models explained 50 %-70 % variance in GP depth and ∼90 % variance in GP volumes. Our GP volume estimates are also within 7 % and 17 % of the total reported and measured volumes in Diamond Valley and Harney Basin, respectively, and the estimated average irrigation efficiency of 87 % aligns with known center-pivot system efficiencies. Additionally, the OpenET ensemble proves to be useful for identifying discrepancies in metered GP data, which are subsequently flagged as outliers. Results from this study illustrate usefulness of satellite-based ET estimates for estimating GP and metered GP data quality control and have the potential to help estimate historical GP.

Treating Tropospheric Phase Delay in Large-scale Sentinel-1 Stacks to Analyze Land Subsidence

Variations in the tropospheric phase delay pose a primary challenge to achieving precise displacement measurements in Interferometric Synthetic Aperture Radar (InSAR) analysis. This study presents a cluster-based empirical tropospheric phase correction approach to analyze land subsidence rates from large-scale Sentinel‑1 data stacks. Our method identifies the optimum number of clusters in individual interferograms for K‑means clustering, and segments extensive interferograms into areas with consistent tropospheric phase delay behaviors. It then performs tropospheric phase correction based on empirical topography-phase correlation, addressing stratified and broad-scale tropospheric phase delays. Applied to a six-year data stack along a 1000-km track in Iran, we demonstrate that this approach enhances interferogram quality by reducing the standard deviation by 50% and lowering the semivariance of the interferograms to 20 cm2 at distances up to 800 km in 97% of the interferograms. Additionally, the corrected time series of deformation shows a 40% reduction in the root mean square of residuals at the most severely deformed points. By analyzing the corrected interferograms, we show that our method improves the efficiency of country-scale InSAR surveys to detect and quantify present-day land subsidence in Iran, which is essential for groundwater management and sustainable water resource planning.

Assessing the Impact of Groundwater Recharge on Underground Reservoir Replenishment in Eastern Uttar Pradesh, India

Groundwater is considered a fresh resource of water and its uses have tremendously increased in the recent past due to an increase in population, rapid urbanization, and industrialization. In India, the groundwater level is declining in some parts of the country due to over-exploitation, low or negligible recharge of aquifer systems, and unsustainable development of groundwater resources. The groundwater modeling is an important tool for studying the past and present groundwater behavior and in the development of future strategies for sustainable groundwater management plans. To study the Impact of groundwater recharge on the replenishment of underground reservoir, Ballia district of Uttar Pradesh has been selected which is one of the districts of the most populous state of India, Uttar Pradesh. An attempt has been made to develop a groundwater model using Modflow software to simulate the groundwater trends and predict future groundwater heads. The calibration and validation of the model were done for 5 years and 3 years respectively. The correlation coefficient for calibration and validation was found 0.85 and root mean square errors vary from 2.89 to 3.2m variation in future trends of groundwater heads. The results of the study show that the developed model can be effectively used to predict the future groundwater heads. The groundwater flow was observed from the northwest to southeast direction. It was predicted from the study that groundwater draft will increase by 10% with a decrease in groundwater level by approximately 0.24 m in the north-west direction by the year 2025. However, no impact was observed in the south side of the district and it was predicted that the groundwater level would remain the same in this zone during the next 3 years.

Spatial analysis of thermal groundwater use based on optimal sizing and placement of well doublets

This paper proposes an approach to optimize the technical potential of thermal groundwater use by determining the optimal sizing and placement of extraction–injection well doublets. The approach quantifies the maximum technically achievable volume of extracted groundwater in a given area and, hence, the amount of heat exchanged with the aquifer, considering relevant regulatory and hydraulic constraints. The hydraulic constraints ensure acceptable drawdown and rise of groundwater in extraction and injection wells for sustainable use, respectively, prevention of internal hydraulic breakthroughs, and adequate spacing between neighboring doublets. Analytical expressions representing these constraints are integrated into a mixed-integer linear optimization framework allowing efficient application to relatively large areas. The applicability of the approach is demonstrated by a real case study in Munich, where the geothermal potential of each city block is optimized independently. Six optimization scenarios, differing in terms of required minimum installed doublet capacity and spacings between doublets, underline the adaptability of the approach. The approach provides a comprehensive and optimized potential assessment and can be readily applied to other geographic locations. This makes it a valuable tool for thermal groundwater management and spatial energy planning, such as the planning of fourth and fifth generation district heating systems.

Reversibility of seawater intrusion in a coastal aquifer: Insights from long-term field observation and numerical modeling

It is essential to understand basis processes affecting the reversibility of seawater intrusion (SWI) and the related timescale after groundwater pumping stopped for coastal groundwater management. Groundwater salinity variations presented by previous studies showed a fast SWI process and the following seawater retreat (SWR) process indicated by overall salinity decrease in the coast karst aquifer in the Dalian Peninsula, northeast China. Cross-sectional variable-density flow and transport simulations using equivalent porous medium (EPM) model, dual-domain (DDM) model and the EPM with a single discrete feature representative of conduit flow (EPM-DF) are conducted to understand the SWI reversibility related to the characteristics of the flow system, including aquifer parameters and seaside boundary conditions. Large dispersity combined with a low salinity concentration at the sea boundary are necessary in the EPM and DDM models to produce a fast SWI and low salinity concentration as observed. The enhanced dispersion in the DDM model enhances the mixing in the transition zone (TZ) and produces more obvious seasonal variation but longer SWR process compared to the EPM model. The EPM-DF model produces significant salinity seasonal variation during the SWI process and a fast decrease in the SWR process. The overall fast system response but low peak concentration during the SWI might be attributed to the highly heterogeneous characteristics of the karst aquifer system, which produces a wide front edge of TZ as observed. The dispersion-dominated EPM and DDM models produced higher degree of SWI reversibility compared to the EPM-DF model, as indicated by the weaker lag effects between groundwater levels and salinity concentration. Moreover, the SWI reversibility may arise not only from the heterogeneous characteristics of the karstic aquifer system but also from the rate for rise in the inland groundwater level during the seasonal variation cycle. An overall SWR process can be divided into two stages: the first stage with rapid decrease in salinity concentration but small changes in toe associated with TZ widening and the second stage with rapid toe retreat during aquifer flushing. The flushing of the brine leakage from the solar salt field may extend the SWR process. Considering this relatively longer water quality response time than the time span in general groundwater management plans, a reasonable objective and how maintain the hydraulic head during the SWI controlling have been of a great concern to the coastal groundwater management.

Toward Decontamination in Coastal Regions: Groundwater Quality, Fluoride, Nitrate, and Human Health Risk Assessments within Multi-Aquifer Al-Hassa, Saudi Arabia

Contamination in coastal regions attributed to fluoride and nitrate cannot be disregarded, given the substantial environmental and public health issues they present worldwide. For effective decontamination, it is pivotal to identify regional pollution hotspots. This comprehensive study was performed to assess the spatial as well as indexical water quality, identify contamination sources, hotspots, and evaluate associated health risks pertaining to nitrate and fluoride in the Al-Hassa region, KSA. The physicochemical results revealed a pervasive pollution of the overall groundwater. The dominant water type was Na-Cl, indicating saltwater intrusion and reverse ion exchange impact. Spatiotemporal variations in physicochemical properties suggest diverse hydrochemical mechanisms, with geogenic factors primarily influencing groundwater chemistry. The groundwater pollution index varied between 0.8426 and 4.7172, classifying samples as moderately to very highly polluted. Similarly, the synthetic pollution index (in the range of 0.5021–4.0715) revealed that none of the samples had excellent water quality, with various degrees of pollution categories. Nitrate health quotient (HQ) values indicated chronic human health risks ranging from low to severe, with infants being the most vulnerable. Household use of nitrate-rich groundwater for showering and cleaning did not pose significant health risks. Fluoride HQ decreased with age, and children faced the highest risk of fluorosis. The hazard index (HI) yielded moderate- to high-risk values. Nitrate risks were 1.21 times higher than fluoride risks, as per average HI assessment. All samples fell into the vulnerable category based on the total hazard index (THI), with 88.89% classified as very high risk. This research provides valuable insights into groundwater quality, guiding water authorities, inhabitants, and researchers in identifying safe water sources, vulnerable regions, and human populations. The results highlight the need for appropriate treatment techniques and long-term coastal groundwater management plans.

Spatiotemporal patterns of groundwater over South Korea

Understanding the large-scale spatiotemporal pattern of multi-depth groundwater levels is critical to develop water management plans and policies for sustainable ecological and social prosperity, which are still lacking. Here, we investigate three major spatiotemporal modes of groundwater levels from ∼200 groundwater monitoring stations over the southern Korean Peninsula (2009–2020), using the Cyclostationary empirical orthogonal function analysis. The first two major modes are associated with the seasonality of recharge and discharge and groundwater use during the 2016/17 drought, which explained half of the total variance. The third major mode indicated a decreasing trend of deep groundwater levels over the western Korean Peninsula, where key administrative and authority offices have been relocated via balanced national land development policies. Furthermore, at least three million Koreans over this region likely experience groundwater depletion by the 2080s. Observational evidence of emerging groundwater depletion suggests a window of opportunity for pre-emptive groundwater management plans.

Towards Sustainable Water Solutions: Investigating Groundwater Possibility in Dindori District of Madhya Pradesh, India

Groundwater is a crucial resource, as approximately 45% of irrigation and around 80% of domestic water needs in India are fulfilled by groundwater reservoirs. Therefore, it is essential to determine where the probability of groundwater availability is high and where it is low. In areas with low probability, there is a need for the rapid development of recharge structures. GIS and remote sensing technology is a crucial tool for obtaining information about availability of ground water potential as well as finding suitable site for recharge structures. The investigation will involve geological surveys to understand the hydrogeological characteristics of the region, including aquifer properties, recharge mechanisms, and groundwater quality. Additionally, environmental impact assessments will be conducted to evaluate the sustainability of groundwater extraction and its potential implications on the surrounding ecosystems. Furthermore, socio-economic analyses will explore the existing water usage patterns, community needs, and stakeholders' perspectives to develop inclusive and equitable groundwater management plans.
 "This study focuses on the Dindori district in Madhya Pradesh, India. There are different factors affecting groundwater recharge, including topography, slope, land use and land cover, drainage density, geology, soil distribution, rainfall, lineament, etc. Satellite images provide information about land use/land cover, geomorphology, and DEM delineate slope, drainage, and lineament. They are classified into different classes and assigned weights. ArcGIS software was used for data integration and weighted overlay analysis to create a groundwater potential map for the Dindori district. The groundwater potential map is categorized into five classes: 'Excellent' (0.01%), 'Good' (9.78%), 'Moderate' (70.04%), 'Poor' (19.97%), and 'Very Poor/Nil' (0.17%)."

Geophysical Subsurface Mapping Using the Electrical Resistivity Technique: A Comprehensive Study of the Petroleum Training Institute Main Campus in Effurun

The electrical resistivity method was used to conduct a detailed examination of subsurface geology and hydrogeological parameters at the Petroleum Training Institute (PTI) Main Campus in Effurun, Nigeria. The research includes field data collecting, sounding curve interpretation, and dipole-dipole data processing. Both qualitative and quantitative methods were employed to gain a complete understanding of the hydrogeophysical features of the research area. The analysis revealed A and AK formations, which include four, five, and six-layer structures, highlighting the subsurface's intricacy. A frequency table was utilised to categorise the distribution of VES curves within the study area into three major groups. This classification was critical for characterising and comprehending the area's hydrogeological and geological complexity. Geo-electric sections were created to illustrate the different underlying layers, such as topsoil, clayey sand, sand, sandstone, and fracture. The study analyzed geoelectric properties and aquifer zones using resistivity isopach maps in 2D and 3D formats. The northeastern part of the study area had higher resistivity values, indicating geological variables affecting rock composition and groundwater supply. The findings are crucial for effective groundwater resource management, environmental assessments, and regional development planning. The geological model, combining data from dipole-dipole, geo-electric, and VES sections, accurately characterized subsurfaces in the PTI Campus area. The study identified six subsurface layers, providing baseline data for future infrastructure development. Recommendations include using advanced geophysical methods and a more detailed assessment of subsurface geology in the Warri region. This study adds to our understanding of the hydrogeological and geological aspects of the PTI Campus area, allowing us to make more informed judgements concerning environmental and infrastructure design. The study offers a comprehensive analysis of subsurface geology and hydrogeological parameters at PTI Main Campus, contributing valuable insights for groundwater management, environmental assessments, and regional development planning.

Hydrogeological Implications of Slope and Land Use/Land Cover Distribution in Part of Southern, Nigeria

The study focuses on the hydrogeological implications of slope and Land Use/Land Cover (LULC) distributions in the Aniocha and Oshimili regions of Nigeria. Understanding the spatial variations in these parameters is critical for effective groundwater management and sustainable land use planning in these areas. The aim is to assess the spatial distribution of slopes and LULC types and their impact on groundwater recharge and surface runoff in the study area. The study employs spatial analysis techniques to categorize slope data into five classes and LULC data into seven types for the years 2017 and 2023. The analysis covers Aniocha North, Aniocha South, Ika North, Ika South, Oshimili North, and Oshimili South. The slope analysis reveals that the largest area (1022.73 km²) falls within the 0-1.52° slope category, indicating predominantly flat terrain with high infiltration potential. The LULC analysis shows that in 2017, trees covered the most extensive area (2143.21 km²), which decreased to 1573.76 km² by 2023, indicating significant deforestation. Built areas expanded from 281.76 km² to 391.99 km², reflecting increased urbanization. Flat terrains (0-3.51°) are conducive to groundwater recharge due to their high infiltration rates, whereas steeper slopes (3.51-26.00°) exhibit higher runoff potential, impacting groundwater recharge negatively. The reduction in tree cover and expansion of built areas have significant hydrogeological implications. Deforestation reduces groundwater recharge potential, while urbanization increases surface runoff, potentially leading to flooding and reduced groundwater levels. The study highlights the need for integrated land and water management strategies to balance development with environmental sustainability. Protecting and managing flat areas for groundwater recharge, implementing soil conservation in steeper regions, and promoting sustainable agricultural practices are essential. Urban planning should incorporate green infrastructure to mitigate the impacts of increased impervious surfaces. This study provides a comprehensive analysis of slope and LULC changes over time and their hydrogeological implications, offering valuable insights for sustainable land and water resource management in the Aniocha and Oshimili regions.

How Human Activities Affect Groundwater Storage.

Despite the recognized influence of natural factors on groundwater, the impact of human activities remains less explored because of the challenges in measuring such effects. To address this gap, our study proposes an approach that considers carbon emissions as an indicator of human activity intensity and quantifies their impact on groundwater storage. The combination of carbon emission data and groundwater storage data for 17,152 grid cells over 16 years in 4 typical basins shows that they were generally negatively correlated, whereas both agriculture and aviation had positive impacts on groundwater storage. The longest impact from aviation and agriculture can even persist for 7 years. Furthermore, an increase of 1 Yg CO2/km2 per second in emissions from petroleum processing demonstrates the most pronounced loss of groundwater storage in the Yangtze River Basin (approximately 4.1 mm). Moreover, regions characterized by high-quality economic development tend to have favorable conditions for groundwater storage. Overall, our findings revealed the substantial role of human activities in influencing groundwater dynamics from both temporal and spatial aspects. This study fills a crucial gap by exploring the relationship between human activities and groundwater storage through the introduction of a quantitative modeling framework based on carbon emissions. It also provides insights for facilitating empirical groundwater management planning and achieving optimal emission reduction levels.

Contributions of Climate Variability and Anthropogenic Activities to Confined Groundwater Storage in Hengshui, North China Plain

Groundwater storage (GWS) in confined aquifer systems is often influenced by climate variability and anthropogenic activities, and it is vital to quantify their contributions for the purpose of groundwater management and surface water allocation plans. In this study, we characterize the spatiotemporal evolution of the GWS in confined aquifer systems across Hengshui, North China Plain, and investigate its relationships with changing climate conditions and human activities through the integration of InSAR-derived surface displacements with hydraulic head observations and precipitation data, during 2004–2010 and 2016–2020. Our results indicate that the GWS in confined aquifer systems decreased markedly by 4.59 ± 0.35 km3 with an accelerating trend during the study period. The GWS variations show a strong correlation with precipitation during irrigation periods (March to July), and hence, the climate and anthropogenic-driven GWS variations can be separated from each other with a linear model. We find that the GWS depletion caused by climate variability and anthropogenic activities were −0.31 ± 0.10 km3 and −4.28 ± 0.40 km3, respectively, during the study period. The mean contribution of anthropogenic activities to the GWS variations was −71.9%, implying that the GWS variations in confined aquifer systems were primarily anthropogenic driven. It is also found that the well observations alone poorly characterize the spatiotemporal evolution of the GWS due to their limited spatial density, and the integrated InSAR/well approach appears to be promising for overcoming this challenge.

Coupled processes of groundwater dynamics and land subsidence in the context of active human intervention, a case in Tianjin, China

To address the crisis of water shortage in the North China Plain, the Chinese government implemented the South-to-North Water Transfer Project (SNWTP). In this context, Tianjin, one of the main beneficiaries of this project, has been relieved from water shortages and begun to implement Groundwater Management Plans (GMP) since 2018, which undoubtedly have a significant effect on the groundwater recovery. Meanwhile, this provides a good case for studying the coupled process of ground settlement and groundwater dynamics, especially the soil deformation pattern driven by groundwater level (GWL) rebound. To analyze these issues in detail, field well data was collected to depict groundwater flow field. Moreover, geodetic data was also collated, including leveling, GPS, and InSAR, so that a vertical deformation field with high spatiotemporal resolution could be generated. The results reveal that the GWL of the third confined aquifer which is the main exploitation layer in Tianjin recovered significantly since 2018 with a rate of 2.1 m/yr. The dynamic deformation patterns indicate that the area of land subsidence cones in Tianjin has reduced significantly, accompanied by a sharply declining subsidence rate (decreased from −32.2 mm/yr to −4.5 mm/yr.). Particularly, a significant poroelastic rebound has occurred in the Wuqing and Beichen districts since 2020. Furthermore, due to the delayed pore pressure dissipation in the aquitard, we find a time delay of 0.3–5.5 years between land subsidence and GWL time series, which is far less than that estimated by hydrogeological parameters, as the latter ignored the recharge and recovery capacity of the aquifer system. Finally, an evolution models in Tianjin was presented to illustrate interactive process among the deformation, pore pressure, and hydraulic head. In general, the SNWDP and the GMP has restored the pore pressure of aquifer, reduced the land subsidence, and alleviated the groundwater storage depletion of Tianjin.

Geospatial Multi-Criteria Evaluation Using AHP–GIS to Delineate Groundwater Potential Zones in Zakho Basin, Kurdistan Region, Iraq

Groundwater availability in the Zakho Basin faces significant challenges due to political issues, border stream control, climate change, urbanization, land use changes, and poor administration, leading to declining groundwater quantity and quality. To address these issues, this study utilized the Analytic Hierarchy Process (AHP) and geospatial techniques to identify potential groundwater sites in Zakho. The study assigned weights normalized through the AHP eigenvector and created a final index using the weighted overlay method and specific criteria such as slope, flow accumulation, drainage density, lineament density, geology, well data, rainfall, and soil type. Validation through the receiver operating characteristic (ROC) curve (AUC = 0.849) and coefficient of determination (R2 = 0.81) demonstrated the model’s accuracy. The results showed that 17% of the area had the highest potential as a reliable groundwater source, 46% represented high-to-moderate potential zones, and 37% had low potential. Flat areas between rivers and high mountains displayed the greatest potential for groundwater development. Identifying these potential sites can aid farmers, regional planners, and local governments in making precise decisions about installing hand pumps and tube wells for a regular water supply. Additionally, the findings contribute to the development of a sustainable groundwater management plan, focusing on improving water usage and protecting water-related ecosystems in the region. Identification of the optimum influencing factors, arrangement of the factors in a hierarchy, and creation of a GWPI map will allow further planning for groundwater preservation and sustainability. This project can be conducted in other areas facing droughts.

Mapping and identification of potential groundwater development zones of an alluvial aquifer in parts of Ghaggar and Upper Yamuna basins in India.

Using an integrated analytical hierarchy process, remote sensing and geographic information system techniques, the current study aims to map and identify the potential groundwater zones of Kurukshetra District of Haryana, which is located in the Ghaggar and Upper Yamuna Basins in India. This is done in the context of a significant change in the use of groundwater pattern, with respect to its continuously increasing demand due to the growing population, expansion of area under irrigation and related economic factors. The amount and quality of groundwater are anticipated to be impacted by anthropogenic activities as well as natural factors such as geomorphology, soil type, lithology and rainfall variance owing to a changing climatic scenario. The potential index of groundwater for this study was calculated by using nine important factors, including geomorphology, rainfall, soil type, depth to groundwater level, lithology, land use land cover, normalized difference vegetation index, cumulative sand thickness and elevation. The integration of multiple thematic layers was accomplished using the overlay weighted method to generate a potential groundwater zonation map and the accuracy of the resulting map was validated against a groundwater resource potential map. Statistical measures demonstrate an 82% agreement between the two maps, indicating a high level of concurrence. Accordingly, three groundwater zones of good, average and bad potential have been identified in the study area. In the current study, a process that combines weighted ranking with spatial data transformation and harmonization has been developed to obtain information for accurate decision-making. The results accruing from this research have significant ramifications for creating regional sustainable groundwater management plans.

Groundwater Management: A Case Study of District Shopian

Water is a natural resource and a blessing present on the earth. It is the water that makes our planet special as it is responsible for the existence of all forms of life. The water may be present on the earth’s surface, in the atmosphere or below the earth’s surface. The water present below the earth’s surface is called as groundwater. Groundwater water has attained a great attention in present day life as the surface water bodies are getting polluted day by day due to various activities. But the overexploitation and unscientific use of groundwater has led to the decline in the quantity of groundwater. Thus, the need of the hour is the proper management of groundwater resources for sustainable development. The present day study focus on the groundwater management plan in district Shopian base on parameters like Groundwater potential of area, quality, artificial recharge site etc.

Sensitivity Analysis for Multi-Criteria Decision Analysis Framework for Site Selection of Aquifer Recharge with Reclaimed Water

The pressure on Egypt’s limited water resources has increased as a result of the country’s growing industrial and agricultural sectors, coupled with climate change impacts and population growth. To overcome the current water stress situation, the utilization of new technologies such as managed aquifer recharge (MAR) is thought to be key for expanding the use of non-conventional water resources and providing necessary water supplies. Managed aquifer recharge can boost groundwater recharge and promote greater water accessibility. Suitability maps for MAR are widely offered as a tool to aid in decision-making in the context of balancing water demand and supply. Conducting a sensitivity analysis to validate suitability mapping can enhance the understanding of the results and pinpoint the influencing factors. The West Delta region was chosen as a case study given the existence of two MAR sites to examine the suitability of implementing MAR projects with reclaimed water. In this work, a spatially explicit sensitivity analysis is performed on a newly developed framework for MAR suitability maps that use multi-criteria decision analysis (MCDA) to determine suitable locations for MAR implementation, using spreading methods techniques. The performed sensitivity analysis uses spatial visualization to examine the effect of various weighted criteria on the final outputs and identifies criteria that are especially sensitive to weight changes. The results of the sensitivity analysis indicate that the applied MCDA framework for the suitability mapping in West Delta produced robust results in terms of the most suitable sites for MAR. The obtained results also indicate the possibility of the use of the suggested framework for arid environments with comparable data availability. Moreover, the results emphasize the possible use of suitability maps in sustainable groundwater management plans to support the actual implementation of MAR projects in the West Delta.

Comparison of GIS-Based Intrinsic Groundwater Vulnerability Assessment Methods: DRASTIC and SINTACS

The possibility of contaminants percolating and diffusing into the groundwater system is referred to as groundwater vulnerability. When groundwater once gets polluted it is very difficult to process/clean it so, measures must be taken to assess the vulnerability of the groundwater for effective groundwater conservation and management planning. This study aims to evaluate and map the vulnerability of Raipur city using the SINTACS and DRASTIC models and to compare their effectiveness between them. To assess the hydrogeological setting and evaluate aquifer vulnerability, each model includes seven environmental parameters (aquifer hydrogeologic features, effective infiltration, topographic slope, soil media, water table depth, unsaturated conditions, and hydraulic conductivity). The parameter data sets are evaluated in a Geographical Information system (GIS) environment to get the vulnerability index (VI), the index is categorized into five classes that show low to high vulnerability. The area under the low class for DRASTIC and SINTACS is 26.14% and 20.34% respectively whereas for the highly vulnerable class it is 15.54% and 22.54% respectively of the total area. By comparing the 15-groundwater sample value of nitrate concentration on the two vulnerability maps it was found that the SINTACS method result was shown to be significantly associated with the nitrate concentration with an accuracy of 86.7 percent.

Factoring Impacts to Water Supply Well Operations into Groundwater Management Planning.

Groundwater management planning requires balancing the interests of different stakeholder groups because (1) water supply development causes changes to groundwater systems that include declines in groundwater levels and (2) benefits and costs from pumping the common-pool resource often do not occur such that they are shared proportionate to use. Quantifying impacts from declining groundwater levels among user groups can be useful for evaluating management strategies. In California, considering impacts to supply well operations is proving important for acceptance of management plans that have been required by law. A case study is presented to illustrate the types of results that may contribute to the planning process. The results indicate that significant differences in impact may occur between groundwater pumpers. Suggestions are provided for using this information to mitigate impacts to the most vulnerable stakeholders.