Understanding the susceptibility of groundwater of Sundarbans with hydroclimatic variability and anthropogenic influences

• Published in: Groundwater for sustainable development 2024-05, Vol.25, p.101135, Article 101135
• Main Authors: Mondal, Mijanur, Mukherjee, Abhijit, Das, Kousik, Puppala, Harish
• Format: Article
• Language: English
• Subjects: Climate change stress; Coastal aquifer; Drinking water vulnerability; Groundwater quality; Seawater intrusion; Sundarbans
• ISSN: 2352-801X; 2352-801X
• DOI: 10.1016/j.gsd.2024.101135

Groundwater salinization of coastal aquifers as a result of climate change and anthropogenic activities is a widely acknowledged phenomenon. Sundarbans, in India is one such area where this phenomenon is noticed at an unprecedented rate making drinking water unpotable for consumption. Studies identifying the prime drivers causing this detrimental phenomenon are limited as the existing studies explicitly lack analyzing the holistic view. Building on this gap, this study aims to conduct a systematic literature review and identify the list of drivers that are promoting groundwater salinization. The influence of wide range of parameters depicting the climate change i.e., varying rainfall pattern, sea level rise (SLR), El Nino-Southern Oscillation (ENSO) and tropical cyclones (TC) on qualitative and quantitative variations in the groundwater at various temporal scales is studied with the help attributes collected from literature. The study reveals a significant drop in groundwater levels (GWL) between 1996 and 2017. This depletion is noted to be primarily attributed to variations in the Indian Ocean Dipole (IOD) and El Niño Southern Oscillation (ENSO), affecting rainfall patterns and recharge rates. During tropical cyclones, GWL rapidly raised, while it is noted that the groundwater quality is sensitive to ENSO. Sea-level rise, changing rainfall patterns, and increasing population density exacerbate groundwater salinization. Existing sources of water, i.e., shallow aquifers exhibit high salinity, and deep aquifers exceed permissible limits. The study evidences the needs to address drinking water scarcity and potential migration resulting from these complex interactions between climate, population, and groundwater management. [Display omitted] •Hydroclimatic drivers leads to groundwater salinization.•Threat to unprojected groundwater response will lead to drinking water scarcity.•Increase in sea level rise is in coherence with the trend of groundwater salinity.