Groundwater (GW) systems are dynamic with climate, where precipitation and evapotranspiration replenish and deplete the aquifers, respectively. In addition to this, human adaptations change alter the groundwater characteristics in a region. Thus, the spatio-temporal variations in climate and anthropogenic factors induce variability in GW systems, albeit with a time lag. An inadequacy of studies regarding relationships between climate and GW has acutely restricted the ability to assess the complex feedback loops between groundwater and climate change – particularly on regional scales (IPCC, 2007 ; IPCC, 2001). Also, the uncertainties in projected GW recharge originating in the hydrological models need exploration (IPCC, 2021).
Trends in Groundwater storage anomalies (cm/yr) between 2003-2016. Computed using GRACE Spherical Harmonic TWS and GLDAS Soil Moisture data.
There is some evidence suggesting a dynamic relationship between the ENSO and the Indian Summer Monsoon (ISMR). Therefore, the complex teleconnections between such climatic modes and the ISMR can potentially propagate to groundwater systems via changes in the monsoon precipitation patterns. However, only a handful of studies have investigated climate and groundwater teleconnections in the Indian context. As a result, the influence of climate on local GW recharge and extraction patterns in various parts of the country is relatively unexplored.
Until recently, the lack of groundwater data has hampered the advancement of similar studies in India. However, concerted field campaigns and efforts to set up long-term monitoring stations by government agencies and academic institutions have resulted in multidecadal groundwater data availability. In particular, the central Indian region has robustly built meteorological and groundwater datasets. In addition, the heterogeneity of groundwater aquifer systems in the central Indian region enables a better understanding of spatial and temporal distributions of feedback processes. From a climate variability perspective, parts of arid and semi-arid areas of western and peninsular India are potential groundwater hotspots that are likely to face groundwater stress in the future.
However, the climatic variabilities in these regions would not confine their effects on regional aquifer systems. So, considering these factors, the proposed study is intended to focus on the central Indian region primarily. We intend to study the effects of the prevailing dry climate on the groundwater resources which are already under stress. We expect to model and study scenarios where groundwater depletion results in feedback to the regional climate.