Groundwater Draft Research Articles

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.

Optimising groundwater recharge to counteract seawater intrusion through an inverse modelling approach and identifying efficient recharge structure locations

In semi-arid coastal urban regions, groundwater faces challenges from seawater intrusion due to reduced recharge and increased extraction. This study employs advanced numerical modeling to comprehensively assess seawater intrusion along the South Chennai coast from 2018 to 2022. The inverse modelling approach utilizes observed data, such as groundwater heads or concentrations, to estimate aquifer properties, like hydraulic conductivity, by minimizing the disparity between model predictions and actual measurements to identify the best-fit parameter values. This inverse method forecasts the necessary recharge rate to address seawater intrusion by increasing groundwater head and decreasing chloride concentrations. The estimation of recharge incorporates variables such as rainfall, soil infiltration capacity, land use, and the vital groundwater draft calculated based on per capita consumption and population. The study uses FEFLOW software to develop a robust conceptual model, simulating groundwater flow and chloride transport. The inverse modeling approach resulted in critical recharge adjustments, enhancing rates by 40%–60% in specific regions. The predictive scenarios, integrating proposed recharge structures, show promising results, notably with a 50% reduction in chloride concentration during the post-monsoon season compared to the pre-monsoon period in wells 8 and 3. A notable decrease in chloride concentration of over 90% was observed during May 2025 in well no: 15 due to its proximity to the Adayar River. These fluctuations are influenced by seasonal variations resulting from climatic changes in South India, with intense rainfall accompanying northeast monsoon winds playing a significant role. Increased recharge rates and strategically placed structures along the Buckingham Canal provide significant relief in the most impacted northern coastal area, acting as effective barriers. These interventions successfully reduce chloride concentration, providing a sustainable and effective solution to mitigate the persistent challenge of seawater intrusion.

Catchment-Wide Groundwater Budget for the Inkomati-Usuthu Water Management Area in South Africa.

In South Africa, approximately 98% of the predicted total surface water resources are already being used up. Consequently, the National Water Resource Strategy considers groundwater to be important for the future planning and management of water resources. In this case, quantifying groundwater budgets is a prerequisite because they provide a means for evaluating the availability and sustainability of a water supply. This study estimated the regional groundwater budgets for the Inkomati-Usuthu Water Management Area (Usuthu, Komati, Sabie-Sand, and Crocodile) using the classical hydrological continuity equation. The equation was used to describe prevailing feedback loops between groundwater draft, recharge, baseflow, and storage change. The results were coarser scale estimates which, beforehand, were derived from the 2006 study. In the years to follow, groundwater reliance intensified and there was also the historic 2015/2016 drought. This inevitably led to an increased draft while the rest of the components of the groundwater budgets experienced decreases. Both Crocodile and Sabie-Sand experienced groundwater storage depletion which led to reduced baseflow and groundwater availability, while groundwater recharge contrarily increased due to capture. Conversely, the other two catchments experienced relatively lower drafts with correspondingly higher groundwater availability and recharge while storage change was positive. The results highlighted the need for adaptive water management whose effectiveness relies on predictive studies. Consequently, future models should be developed to capture the spatial and temporal dynamism of the natural groundwater budget due to climate change, water demands, and population growth predictions.

Groundwater scenario under climate change and anthropogenic stress in Ladakh Himalaya, India

ABSTRACT Climate change and human interventions over the past few decades have significantly affected the groundwater resources in Ladakh Himalaya. Sparse or lack of suitable data and knowledge gaps are a major challenge in evaluating these impacts. Here, we synthesize the available data to assess the status of groundwater quantity, quality, withdrawal, and contamination in the Leh district of India. The study shows that glacier area has decreased by 40% whereas its volume has reduced by 25% since the Little Ice Age (∼1650 AD). The glacier melt, which influences the recharge, has reduced significantly. The growth of population by 15% per year, expansion of built-up area by 50%, and changes in the socio-ecology have further stressed the groundwater. The bore wells and groundwater draft have increased at ∼115 wells/year and ∼7 MCM/year, respectively. The increase of groundwater development by ∼26 times has reduced the reserves. Hence, for the sustainability of the resource, modeling and managing the impacts is urgently required. In this direction, this paper provides guidelines for researchers, policymakers, and water users to develop an integrative consortium management strategy for the sustainable utilization of the groundwater.

Multi-collinearity Based Parameter Optimization and Comparison among Multi-criteria Decision Analysis to Map Groundwater Potential Zones

Abstract Zonation of groundwater potential is a vital technique for long-term water governance and urban planning, particularly in agrarian countries such as India. As a result, the present groundwater potential mapping study was carried out in Tiruvannamalai district, Tamil Nadu, India to assess the capability of the aquifer using 21 groundwater conditioning parameters. An overlay analysis was performed to create a database for multicollinearity analysis to optimize the parameters. Normalization, weight allocation, and ranking of locations based on the assessment value were performed using Multi Criteria Decision Analysis (MCDA) techniques such as Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and Multi-Objective Optimization based on Ratio Analysis (MOORA). The results of MCDA techniques were integrated with Remote Sensing (RS) and Geographical Information System (GIS) for the identification of groundwater potential zones. Based on the TOPSIS, 5.17 % of the area was classified as very high potential and 9.38 % of the area was classified as a very low potential zones. Similarly, the MOORA technique classified 5.54% of zones as very high and 13.55% as very low potential. Validation of results were done using groundwater level and groundwater draft data and prediction accuracy of MOORA and TOPSIS was found to be more than 80%.

Estimation of groundwater draft in Rajasthan state

Field methods for the estimation of groundwater unit draft are not fully reliable due to non-uniformity of draft in the time domain. In India, use of norm values recommended by the Groundwater Estimation Committee is in common practice. In this study, a computational method for groundwater unit draft estimation for irrigation sources is proposed. This study presents an estimate, projection and analysis of groundwater draft in the different district of Rajasthan State. using the norms of GEC-1997 unit draft as 0.52 and 2.28 ha-m for dug wells and deep tube wells, respectively, annual groundwater draft for irrigation in this area is estimated to be 1524609 ha-m , out of which (10.53%) is withdrawn using diesel pump.

Impact of Water Management Options on Groundwater Draft, Energy Consumption and Carbon Emission in Different Districts of Bihar

Impact of Water Management Options on Groundwater Draft, Energy Consumption and Carbon Emission in Different Districts of Bihar

Evaluation of groundwater status in Thekkumkara Grama Panchayat, Thrissur District, Kerala, India: A geospatial approach

A study has been carried out in Thekkumkara Grama Panchayat of the Thrissur District, Kerala, India, to understand the groundwater status of the area. All hydrogeological information like the principal hydro geological units and their distribution, recharge and discharge areas, sources of water in different regimes, water level fluctuations in a given area over time, water potential, etc, have been collected and analysed to evaluate the groundwater development prospects in the study area. Physiographically, Thekkumkara Grama Panchayat is situated in the highland region. Geologically, the study area is characterised by Charnokites and Migmatites of Precambrian age, covered by Laterites and Lateritic soil. 60 dug wells were observed in the study area and the depth of these wells range between 3.14 to 9.92 m below ground level. Through integrated GIS analysis, it is estimated that about 36% of the study area comes under the very high to high category in terms of groundwater potential. The net annual groundwater availability in Thekkumkara Grama Panchayat is estimated as 8.69 MCM and the total annual groundwater draft for domestic as well as irrigation purposes is estimated as 1.87 MCM. The draft is only 22% of the annual available groundwater in the Thekkumkara Grama Panchayath. The agricultural operations are mainly rain fed and there are no major water consuming industries. For future groundwater development, the area can be categorized as ‘Safe’ based on the present level of groundwater utilization.

MODELLING IMPACT OF CROPPING PATTERN AND URBAN AREAON GROUNDWATER RESOURSES OF NAGARJUNA SAGAR RIGHTCANAL COMMAND AREA USING VISUAL MODFLOW

Groundwater models can be used for the assessment of the impact of the different cropping pattern andchange in urban area on groundwater resource and modeling is the best tool to optimize the differentcombinations or scenarios and to select the best combination or scenario for management of sustainablegroundwater resources. In this study, three-dimensional finite-difference groundwater model VisualMODFLOW 2.8.1 was used to simulate the groundwater dynamics in Nagarjuna Sagar Right CanalCommand area. The net area irrigated under Nagarjuna Sagar Right Canal is 4.75 lakh ha. Calibration andvalidation of the model has been carried out and used to predict the static groundwater storage availabilityin the study area for different cropping pattern scenarios and change in the urban area. The validatedVisual MODFLOW 2.8.1 was used to simulate the groundwater dynamics in the study area for the years2030 and 2040 with different cropping pattern scenarios and change in the urban area. Global climatemodel MarkSim, which is developed by the International Centre for Tropical Agriculture (CIAT) was usedto generate future weather data for the years 2030 and 2040. The impact of change in cropping pattern onstorage of static groundwater resource in the study area for the years 2030 and 2040 was assessed with twoscenarios of change in rice cropped area decreased by 50 per cent and 100 per cent with this cropped areacultivated equally by the ID crops. These results showed that the lesser storage of static groundwaterresources in future lesser. The change in the cropping pattern affects the net recharge of the groundwaterwhich influences the groundwater levels. Increase in paddy area increases the recharge and rise ingroundwater level has been identified. In the study area, cropping pattern could be changed from rice cropto other irrigated dry crops to prevent the increase of groundwater resources which leads the water loggingcondition in the study area. The urbanization is one of the most significant factor considering for assessmentof the response on the groundwater levels and availability of static groundwater resources. The groundwaterrecharge is very less in case of increase in urban area and generates more runoff rather than the intake ofrainfall in the ground surface as having the impervious nature. In view of increase in urban area in thestudy area, the four scenarios are proposed with the combination of 10 per cent and 20 per cent decrease inrecharge and 50 per cent and 100 per cent increase in groundwater draft and simulated the groundwater fluctuations for the years 2030 and 2040. The impact of change in the urban area on storage of availablestatic groundwater resource in the study area for the years 2030 and 2040 was assessed with four scenarioscombination of groundwater recharge and groundwater pumping. The storage of static groundwaterresources would be expected in future lesser than the present storage of static groundwater resources in allscenarios due to increase in urban area as increased in impervious nature of the ground surface. The declinein available static groundwater resources would be expected 6.38 per cent and 7.08 per cent during 2030and 2040 respectively. The rapid expansion in the urban area and their settlements is also one of the reasonsfor the depletion of groundwater resources with low recharge and high groundwater draft.

Over Dependency on Groundwater in India: Issues and Insights

The present analysis shows that there is no compatibility between annual rainfall, annual recharge, annual draft, and the number of OCS blocks indicating serious discrepancies in the available information. Apart from this, different groundwater assessments from 2004 show no significant increase in annual groundwater draft, according to a report from the United Nation, groundwater abstraction continued to rise sharply in India. It is also observed that though, there is no significant change in the long-period average annual rainfall of the country, in general, the states in the northwest and central India, like Punjab, Haryana, and Uttar Pradesh are facing a remarkable downward trend in seasonal (monsoonal) and annual rainfalls both. The states of the country’s western region, like Rajasthan and Gujrat, are witnessing an upward trend in both seasonal (monsoonal) and annual rainfalls. States of southern India are not much affected. Due to declining rainfall in some of the major food grain-producing states, the balance of water distribution in the country is shifting and it may become more prominent in the years to come. India is already the largest abstractor of groundwater in the world and in the above scenario, there will be tremendous pressure on groundwater in the future. This calls for out-of-the-box solutions for groundwater restoration in India. The suggested actions which may counter the looming water crisis in the country, particularly in north-western and central Indian states, include increasing forest cover up to 20% in the next 25 years in poorly forested states, limiting area under water-guzzling greenhouse producing gas crops, starting land subsidence survey in cities, limiting groundwater abstraction and injecting water into aquifers, launching group schemes of drip and sprinkler irrigation on a large scale using existing tube-wells/wells, searching the alternative source of water by developing integrated facilities to retrieve, treat, store, and transport wastewater, transferring groundwater from groundwater surplus areas to scarce areas, enacting comprehensive central law on groundwater, improving water and agriculture resource efficiency through the Internet of Things, cloud and sensor-based network, mapping and time-bound renovation of large traditional water bodies (>1 hectare), revisiting groundwater assessment methodology and norms, quantifying static groundwater resource, developing heat tolerant and less water consuming crops and changing food habits.

Sustainability appraisal of arsenic mitigation policy innovations in West Bengal, India

Treatment of arsenic-contaminated shallow groundwater upon extraction has become imperative to provide safe drinking water in remote villages in West Bengal, India. Arsenic removal plants (ARPs) stabilising arsenic-rich waste water ‘in situ’, despite saving valuable time and money, require high technical expertise for operation and maintenance, which is difficult to facilitate in rural communities lacking the necessary infrastructural support. Contrarily, arsenic removal units (ARUs) have been widely accepted by the society for their user-friendliness. However, most of them produce a high volume of hazardous sludge, safe commercial reuse of which can be done by ‘ex situ’ stabilisation with clay bricks. Based on the number of ARPs and ARUs needed to help households seeking remedy, a cost–benefit analysis of the remediation and waste-management aspects is performed by system dynamics modelling. For a major arsenic-affected district of the state, the simulation results suggest that in lieu of ARPs, installation of ARUs is deemed to be financially sustainable for at least 15 years from now, if the arsenic-laden bricks are sold at a price 20% higher than normal. Future projections of groundwater draft and stress in the region commensurately confirm the economic and environmental sustainability of the arsenic remediation.

Potential area of micro-irrigation and its outreach across Indian states

Indian agriculture is predominantly dependent on groundwater and consumes nearly 89% of its total groundwater draft. With recurrence of drought and faster depletion of groundwater resources in recent past, micro-irrigation technology has emerged to play crucial role in managing irrigation water demand and sustaining food security. The policy makers, recognising gravity of water scarcity across the Indian states, have focussed water policy pivotal to micro-irrigation. So, present study aims to estimate potential area across Indian states that are suitable for adoption of micro-irrigation. For estimation, sources of irrigation and crop suitability for micro-irrigation primarily under drip and sprinkler irrigation are considered across the states for year 2018–19. Based on different combinations of irrigation sources, estimate shows that country endows an area of 72–78 million ha on which micro-irrigation can be adopted. At country level, micro-irrigation penetration to our estimates ranges from 14.71–15.81% in recent years. Further, location coefficient reveals that concentration of micro-irrigation has improved over the years, however noticeable variation exists across the states. The states with dedicated agencies to improve micro-irrigation adoption like Andhra Pradesh and Gujarat, show higher penetration. However, the state like Punjab that faces water scarcity has low penetration of micro-irrigation. Therefore, there is need to have state-specific schemes to scale up micro-irrigation area for better trade-off between environmental sustainability and food security.

Estimation of replenishable groundwater resources and their utilization status in hard rock terrain

For an efficient management and development of groundwater resources, it is imperative to have a reliable database on groundwater resources. In this regard, present study was conducted during 2015–18 in Mahatma Gandhi Chitrakoot Vishwavidyalaya, Chitrakoot, Satna, Madhya Pradesh, India. Dynamic groundwater resources of study area have been estimated by using the guidelines of the groundwater resources estimation committee (GEC-1997), Ministry of Water Resources, Government of India. In this study, rainwater infiltration factor (RIF) techniques and different conventional norms were used for groundwater recharge estimation. The assessments of groundwater units were categorized based on stage of groundwater development for the year 2016. The annual groundwater draft for all uses such as domestic and irrigation was 5931.54 ha m. The annual groundwater recharge in the study area was 8666.81 ha m and net annual groundwater availability was 8318.85 ha m. The groundwater utilization and stage of groundwater development had also been determined and the overall stage of groundwater development of Babina block was found to be 71.30%. There was no significant rise or fall of water levels during both the pre-monsoon and post-monsoon intervals in the study area. Considering the stage of groundwater development, it has been categorized that Babina block of Jhansi district, a part of Bundelkhand region falls under ‘SAFE’ category of groundwater development with excellent potential for the future groundwater development.

Assessing the Groundwater Reserves of the Udaipur District, Aravalli Range, India, Using Geospatial Techniques

Population increase has placed ever-increasing demands on the available groundwater (GW) resources, particularly for intensive agricultural activities. In India, groundwater is the backbone of agriculture and drinking purposes. In the present study, an assessment of groundwater reserves was carried out in the Udaipur district, Aravalli range, India. It was observed that the principal aquifer for the availability of groundwater in the studied area is quartzite, phyllite, gneisses, schist, and dolomitic marble, which occur in unconfined to semi-confined zones. Furthermore, all primary chemical ingredients were found within the permissible limit, including granum. We also found that the average annual rainfall days in a year in the study area was 30 from 1957 to 2020, and it has been found that there are chances to receive surplus rainfall once in every five deficit rainfall years. Using integrated remote sensing, GIS, and a field-based spatial modeling approach, it was found that the dynamic GW reserves of the area are 637.42 mcm/annum, and the total groundwater draft is 639.67 mcm/annum. The deficit GW reserves are 2.25 mcm/annum from an average rainfall of 627 mm, hence the stage of groundwater development is 100.67% and categorized as over-exploited. However, as per the relationship between reserves and rainfall events, surplus reserves are available when rainfall exceeds 700 mm. We conclude that enough static GW reserves are available in the studied area to sustain the requirements of the drought period. For the long-term sustainability of groundwater use, controlling groundwater abstraction by optimizing its use, managing it properly through techniques such as sprinkler and drip irrigation, and achieving more crop-per-drop schemes, will go a long way to conserving this essential reserve, and create maximum groundwater recharge structures.

Managing irrigation supplies effectively under interrupted electricity supply: Lesson from an arid region of India

Groundwater extraction through electrically operated tubewells offers a resilient source of irrigation supply in arid regions especially during droughts. However, interrupted and low-voltage electric supply with limited availability and frequent trips increases repair and maintenance costs of tubewell irrigation and reduces tubewell discharge resulting in less-efficient and non-uniform water application. This study evaluates performance of an indigenous system of groundwater irrigation that was evolved over the generations in arid region of Gujarat, India to address electricity-triggered issues of irrigated agriculture. In this system, groundwater extracted during electricity availability hours is stored in surface reservoirs for later supplying to irrigate crops under gravity flow irrespective of electricity availability. A comprehensive survey of the indigenous system is conducted in a village of Gujarat to make inventory of all tubewells and storage reservoirs about their depth, size, pump type and horsepower, command area, crops, irrigation timing and frequency, etc. Discharge of tubewells was measured and their locations were recorded. Results revealed that the indigenous system is advantageous over the direct tubewell-irrigation in terms of 37.4% higher water-delivery rate and 50% more average irrigation capacity. These findings prove adequacy of the indigenous system in regulating irrigation supplies to deal with electricity-induced intricacies of irrigated agriculture. Amount of water lost through unit area of earthen (seepage and evaporation ∼2.77 m) and masonry (evaporation ∼1.22 m) reservoirs collectively accounts for a negligible proportion (0.9%) of groundwater draft. Furthermore, a methodology is devised to precisely estimate village-level groundwater draft for irrigation, which is validated by 0.9% deviation between observed and predicted values of groundwater draft. Moreover, the indigenous system is simple, cost-effective and easy to implement in other parts of the world especially in arid regions of the developing countries where low-voltage and intermitted electricity supply persists.

Estimation of Groundwater Recharge and Draft of Arwal District Watershed based on Changing Trend of Rainfall and Population Forecasting

Increasing demand of fresh water is not only an issue in India but across the world. Rapid growth of population is a major cause of harassing the natural resources and groundwater is one of them. The methodology for groundwater resources assessment in India is mainly based on Ground Water Resources Estimation Committee,1997 and it involves assessment of annual groundwater resources recharge, annual groundwater draft (utilization) and the percentage of utilization with respect to recharge (stage of development). The assessment units (blocks/watersheds) are categorized based on stage of groundwater development (utilization) and the long term water level trend. This study estimates the recharge and draft of Groundwater in Arwal District due to uses for irrigation, domestic and industrial uses, etc. The characteristic of annual rainfall, monsoon rainfall and non-monsoon rainfall were analyzed. The average annual rainfall of Arwal district is 743.05 mm, monsoon rainfall as 654.18 mm and non-monsoon rainfall was recorded as 66.87 mm. Groundwater recharge was estimated at 49766.15 ha-m and draft was determined as 52973.15 ha-m. Population study of district was forecasted using Geographical Increased method. Based on this study results, the total annual demand of water for Domestic purposes was estimated at 41.09 MCM. Draft of groundwater was observed more than recharge of groundwater. This needs proper planning and management of existing groundwater resources.

Distributed groundwater recharge potentials assessment based on GIS model and its dynamics in the crystalline rocks of South India

Extensive change in land use, climate, and over-exploitation of groundwater has increased pressure on aquifers, especially in the case of crystalline rocks throughout the world. To support sustainability in groundwater management require proper understating of groundwater dynamics and recharge potential. GIS based studies have gained immense popularity in groundwater exploration in recent years because they are fast and provide recent information on the resource for future growth. Thus, the present study utilized a GIS-based Weighted Overlay Index (WOI) model to identify the potential recharge zones and to gain deep knowledge of groundwater dynamics. The in situ infiltration tests have been carried out, which is the key process in groundwater recharge and is neglected in many cases for WOI. In the WOI, ten thematic layers from the parameters influencing and involved in the recharge process are considered to identify potential recharge zones. The results suggested a significant underestimation of recharge potential without considering site-specific infiltration rates that one needs to be considered. The present WOI model considered in situ infiltration information and classified the entire area into four recharge zones, good, moderate, poor, and very poor. The final integrated map compared with the real-time field data like water level fluctuation and infiltration to analyse occurrence and quantification of recharge. The estimated average groundwater draft is 21.9 mcm, while annual renewable recharge is only 5.7 mcm that causing a continuous fall of the groundwater table. The study is useful in selecting regions with more focussed recharge studies and suggested the need of reducing groundwater demand by changing cropping patterns through a predictive decision support tool.

The response of groundwater to multiple concerning drivers and its future: a study on Birbhum District, West Bengal, India

Groundwater and its upcoming crisis are the present-day concern of the scientist. This research mainly focuses on responses of groundwater dynamicity to some important drivers, viz. agricultural yield, groundwater irrigated area, groundwater draft, landuse/landcover, and stage of development. The result of this study has been done under three sections. In the first section, the spatiality of groundwater has been discussed where it has been noticed that the western side of the district groundwater level is near the surface due to low drafting and low agricultural yield. Moreover, hard rock geology in the western part disappoints the drilling process. On the eastern part, rich alluvial soil influences high agricultural yield hence groundwater level lowering down rapidly. In the second section, the nature of groundwater levels has been analyzed through the boxplot, and cluster diagram, where boxplots have been drawn over different geological facies, which depicts groundwater is highly fluctuating in hard clay geology. For example, high agricultural intensity and high groundwater draft is the characteristic feature of hard clay geology. The dendrogram in cluster analysis represents a homogeneous groundwater level fluctuating station in three different time series. Last section deals with the future of groundwater level where an artificial neural network (ANN) model has been applied to extract the predicted groundwater level for 2030. This type of environmental analysis, such as groundwater fluctuations in relation to different sensitive parameters and the use of a machine learning model, would aid potential researchers and communities in making wise groundwater use decisions.

Potential and net recharge assessment in paddy dominated Hirakud irrigation command of eastern India using water balance and geospatial approaches

Spatially distributed potential and net recharge rates were assessed in the paddy dominated Hirakud command area (Eastern India) at 100 m grid resolution using surface water balance and Water Table Fluctuation (WTF) methods, respectively, for the period 2001–05. Net recharge estimated using the WTF method corresponding to observation well locations was further interpolated using kriging technique available in the ArcGIS software. Net recharge to potential recharge ratios (%) were also assessed spatially. Water balance components (i) runoff was estimated using the Natural Resources Conservation Service-Curve Number (NRCS-CN) method (ii) reference evapotranspiration by (Hargreaves and Samani, Applied Engineering Agriculture ASABE 1:96–99, 1985)), crop evapotranspiration by (Allen et al., Crop evapotranspiration: Guidelines for computing crop water requirements, FAO Irrigation and Drainage, Food and Agriculture Organization, Rome, Italy, 1998) and evaporation from uncultivated lands by Ritchie (1972) approaches, and (iii) canal seepage using simple canal flow model. Annual groundwater draft during Kharif and Rabi was found to be 144.41 and 112.49 ha-m, respectively. Nearly, 90% of the study area contributed runoff in the range of 200–400 mm during the years 2002–03, 2003–04, and 2004–05. The estimated seepage losses vary between 5 and 15% of irrigation depth for all distributaries. Potential groundwater recharge during wet, normal, and dry years ranges between 650 and 1033 mm, and equivalent to 67%, 78%, and 60% of annual rainfall, respectively. Net recharge ranges between 8 and 11% of the annual rainfall. Mean ratio between net recharge to potential recharge is nearly 30%, indicating that nearly 70% of potential recharge is accounted as outflow from the study area. Parmanpur distributary canal located at the centre of the study area that exhibited higher potential recharge can be scheduled at the end to avoid water logging problem. Further, extraction of groundwater during non-monsoon period for irrigation purpose not only helps in controlling waterlogging but also helps in maintaining stable groundwater level. Overall, spatio-temporal distribution of recharge in the command area indicated that the irrigation demands during non-monsoon season can be met through sustainable management of underexploited groundwater resources. Such an integrated management of surface and groundwater can help in improving water use efficiencies as well as agricultural productivity.

Fuzzy logic algorithm based analytic hierarchy process for delineation of groundwater potential zones in complex topography

Groundwater crisis under the changed climate scenario has now become a global concern. Land use and land cover change and rapid urbanization are some of the prime causes of it. Aquifers are in a vulnerable condition due to the extensive abstraction and over exploitation as the groundwater draft exceeds the groundwater recharge. It is in this context, the present study has been carried out to identify groundwater potential zones of Garbeta block of Paschim Medinapore district of West Bengal, India, which is located in a critical terrain condition and faces extreme water scarcity in terms of both surface and groundwater availability. The region experiences an average annual groundwater level fluctuation between 9 and 11 m. Demarcation of the groundwater potential zones has been made using Fuzzy Analytical Hierarchy Process (Fuzzy AHP) integrated with geospatial techniques. Fuzzy weights have been entrusted to eleven physical parameters namely land use and land cover, soil, geology geomorphology, lineament density, drainage density, relative relief, distance from river, slope, groundwater level fluctuation and normalised difference water index (NDWI), and the final map has been prepared within geospatial environment. The groundwater potential zones have been classified into five classes: very low potential (18.30%), low potential (26.42%), moderate potential (25.99%), high potential (19.55%) and very high potential (9.75%). The calculated results have been validated through field based groundwater level survey. Such studies will provide new vision and incur valuable information to the stakeholders for sustainable water resources management and effective identification of suitable locations for groundwater extraction.