首页|Recharge and vulnerability assessment of groundwater resources in North west India:Insights from isotope-geospatial modelling approach

Recharge and vulnerability assessment of groundwater resources in North west India:Insights from isotope-geospatial modelling approach

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Recent studies indicate dwindling groundwater quantity and quality of the largest regional aquifer sys-tem in North West India,raising concern over freshwater availability to about 182 million population residing in this region.Widespread agricultural activities have resulted severe groundwater pollution in this area,demanding a systematic vulnerability assessment for proactive measures.Conventional vul-nerability assessment models encounter drawbacks due to subjectivity,complexity,data-prerequisites,and spatial-temporal constraints.This study incorporates isotopic information into a weighted-overlay framework to overcome the above-mentioned limitations and proposes a novel vulnerability assessment model.The isotope methodology provides crucial insights on groundwater recharge mechanisms(18O and 2H)and dynamics(3H)-often ignored in vulnerability assessment.Isotopic characterisation of precipitation helped in establishing Local Meteoric Water Line(LMWL)as well as inferring contrasting recharge mechanisms operating in different aquifers.Shallow aquifer(depth<60 m)showed significant evaporative signature with evaporation loss accounting up to 18.04%based on Rayleigh distillation equa-tions.Inter-aquifer connections were apparent from Kernel Density Estimate(KDE)and isotope correla-tions.A weighted overlay isotope-geospatial model was developed combining 18O,3H,aquifer permeability,and water level data.The central and northern parts of study area fall under least(0.29%)and extremely(1.79%)vulnerable zones respectively,while majority of the study area fall under moderate(42.71%)and highly vulnerable zones(55.20%).Model validation was performed using ground-water NO3-concentration,which showed an overall accuracy up to 82%.Monte Carlo Simulation(MCS)was performed for sensitivity analysis and permeability was found to be the most sensitive input param-eter,followed by 3H,18O,and water level.Comparing the vulnerability map with Land Use Land Cover(LULC)and population density maps helped in precisely identifying the high-risk sites,warranting a prompt attention.The model developed in this study integrates isotopic information with vulnerability assessment and resulted in model output with good accuracy,scientific basis,and widespread relevance,which highlights its crucial role in formulating proactive water resource management plans,especially in less explored data-scarce locations.

Agricultural pollutionData scarcityRecharge mechanismRayleigh distillationIsotope-geospatial modelVulnerability assessment

Annadasankar Roy、Sitangshu Chatterjee、Uday Kumar Sinha、Anil Kumar Jain、Hemant Mohokar、Ajay Jaryal、Tirumalesh Keesari、Harish Jagat Pant

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Isotope and Radiation Application Division,Bhabha Atomic Research Centre,Trombay,Mumbai-400 085,India

Homi Bhabha National Institute,Mumbai 400 094,India

Central Ground Water Board,Ahmedabad,Gujarat,India

2024

地学前缘(英文版)
中国地质大学(北京) 北京大学

地学前缘(英文版)

CSTPCD
影响因子:0.576
ISSN:1674-9871
年,卷(期):2024.15(1)
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