Groundwater Variability Across India, Under Contrasting Human and Natural Conditions

Abstract

Characterizing local to regional scale water cycles and water resources will be crucial for achieving the United Nations' water‐related Sustainable Developmental Goals. However, quantification and understanding of groundwater extraction across scales have been hampered by inadequate water usage reporting and limited information on irrigation practices. Here we analyze observations from ∼15,000 groundwater monitoring wells and the Gravity Recovery and Climate Experiment satellites together with irrigation, agricultural, and meteorological datasets to show how drought‐induced coupling between natural and anthropogenic groundwater storage variations has caused sustainability challenges in India, the world's biggest consumer of groundwater for irrigation. Notably, the mechanisms and consequences of such coupling differ significantly depending on aquifer types. In Andhra Pradesh's hard rock aquifer, groundwater declines have been limited, despite the nearly constant water scarcity that its farmers face. Moreover, its free farm power policy involves an annual irrigation energy consumption of 26 billion kWh that costs US$ 2.5 billion, possibly unparalleled compared to any other part of the world of similar size (0.27 million km2). In West Bengal's highly permeable alluvial aquifer, the water table is declining rapidly (15 cm/yr) due to a policy that encourages irrigation. Situated between these two states, Odisha's aquifer shows substantial resilience to drought, owing to the state's relatively natural landscape and forest restoration policy. The findings of this study provide new insights to understand the divergent aspects of groundwater irrigation in north versus south India, which can enable development of adaptation and mitigation strategies to avert the looming water crisis.

Assessment and Mapping of Riverine Flood Susceptibility (RFS) in India through Coupled Multicriteria Decision Making Models and Geospatial Techniques

“…India exhibits an exceptionally varied climate due to its vast geographical extent and diverse topography. The country encompasses six primary climate types, which include tropical monsoon, tropical wet and dry, arid and semiarid, subtropical humid, mountain, and highland [50]. Each of these climate types has distinct characteristics that exert a significant influence on the weather patterns observed across different regions of India.…”

A geospatial machine learning prediction of arsenic distribution in the groundwater of Murshidabad district, West Bengal, India: spatio-temporal pattern and human health risk

“…The unprecedented groundwater development was in response to the needs for securing pathogen-free drinking water and attaining self-sufficiency in food production (Harvey et al, 2005). Massive pumping of groundwater for irrigation and municipal water supply has thus substantially changed the natural groundwater flow system (Mukherjee et al, 2011) and has caused a rapid decline in the water table (15 cm/yr, Panda et al, 2022), which further impacts the long-term geochemical stability of As in the aquifers. Prior studies have shown that As release into the alluvial aquifers of the Ganges River is primarily driven by the microbially-mediated reductive dissolution of Fe-oxyhydroxides coupled to oxidation of sedimentary organic matter (Nickson et al, 1998; McArthur et al, 2001; Harvey et al, 2002; Smedley and Kinniburgh, 2002; Islam et al, 2004; Nath et al, 2008).…”

Geospatial Machine Learning Prediction of Arsenic Distribution in the Groundwater of Murshidabad District, West Bengal, India: Analyzing Spatiotemporal Patterns to Understand Human Health Risk

“…The unprecedented groundwater development was in response to the need to secure pathogen-free drinking water and attain self-sufficiency in food production . Massive pumping of groundwater for irrigation and municipal water supply has thus substantially changed the natural groundwater flow system and has caused a rapid decline in the water table (15 cm/year), which could further impact the long-term geochemical stability of redox-sensitive species, such as As, in the aquifers . Prior studies have shown that As release into the alluvial aquifers of the Ganges River is primarily driven by the microbially mediated reductive dissolution of Fe-oxyhydroxides coupled to oxidation of sedimentary organic matter. − …”