The ongoing collaborative research work between the Indian Institute of Technology (IIT) Kharagpur and Athabasca University, Canada has led to an unprecedented first estimation of Usable Groundwater Storage (UGWS) at the state-level across India. This comprehensive study, which used both in situ and satellite-based measurements, is a significant cornerstone in understanding India’s groundwater scenario.
The Groundbreaking Study
The investigated data includes the total UGWS estimation between 2005 and 2013. The research assembled the information from 3,907 in situ monitoring wells dispersed across India. Hitherto, only estimations of the total groundwater were calculated by government authorities, but never the usable groundwater storage. With India being the world’s greatest consumer of groundwater, utilizing approximately 230 km3 annually, this equates to more than a quarter of the worldwide aggregate.
Key Takeaways from the Research
The report revealed that about 85% of India’s groundwater use is tied to irrigation practices. The period between 2005 and 2013 saw a precipitous drop in UGWS, particularly in northern and eastern regions. These areas lost 8.5 km3/year and 5 km3/year of the total groundwater, respectively. Assam, Punjab, Haryana, Uttar Pradesh, Bihar, and West Bengal featured prominently in the list of states suffering from rapid UGWS depletion.
| State | Annual Precipitation (mm) | UGWS Level (cm) |
|---|---|---|
| Assam | – | Lost 2% of its UGWS |
| Haryana | 689 | 3,593 |
| Himachal Pradesh | 1,147 | 520 |
Reasons behind Groundwater Depletion
The study identified several factors contributing to this alarming trend. A predominant cause is the lack of an organized water supply system, causing increased reliance on groundwater. Secondly, the advent of water-intensive crop cultivation correlates positively with the decrease in groundwater levels. Furthermore, about 85% of rural drinking water requirements, 65% of irrigation needs, and 50%of urban drinking water and industrial demands are met by groundwater, indicating gross overexploitation.
Potential impacts
The rapid depletion of UGWS could heavily impact food production and drinking water availability, both primary targets under UN Sustainable Development Goals 2030. More than 120 million people from the Gangetic states stand at risk. Predicted are intensified summer groundwater droughts that may not only persist but even become severe by 2050, threatening all seasons. This could also lead to a decline in flow in adjacent rivers, impacting river-aquifer interaction.
Suggested Measures
To curb this crisis, India needs to develop a more robust quantitative approach. This could be achieved with the help of advanced hydroscience and data science techniques to understand conjunctive water demands and usages. The research suggests crafting a sustainable groundwater management program, which would necessitate accurate water-stress data. Encouragingly, some southern and western Indian states like Andhra Pradesh, Maharashtra, Gujarat, Chattisgarh have displayed replenishing UGWS trends.