Hydrologie : recherche actuelle

Over Dependency on Groundwater in India: Issues and Insights

Abstract

Pratik Ranjan Chaurasia and R.S.Sinha

Background: India witnessed a sharp decline in rainfall during the decades of 1991-2000 and 2001-2010. But rainfall started improving during the decade 2011-2020 and by the year 2020, the annual rainfall of the country almost became equal to the long period average annual rainfall. Although overall rainfall improved, yet, the present analysis shows that in general, the states in northwest and central India, like Punjab, Haryana, and Uttar Pradesh are facing a remarkable downward trend in seasonal (monsoonal) and annual rainfalls both. The states of the western region of the country, like Rajasthan and Gujrat, are witnessing an upward trend in both seasonal (monsoonal) and annual rainfalls. States of southern India are not much affected.

The present analysis also shows that despite no significant change in the net annual groundwater recharge and annual groundwater draft from 2004, the numbers of over-exploited, critical, and semi-critical blocks rose exponentially after 2011. Further, different groundwater assessments from 2004 show no significant increase in annual groundwater draft, according to a report of the United Nation, groundwater abstraction continued to rise sharply in India. Thus, there seems no compatibility between annual rainfall, annual recharge, annual draft, and numbers of OCS blocks indicating serious discrepancies in groundwater assessment methodology and requiring a serious review of groundwater assessment methodology and norms being adopted in various states of India. Due to declining rainfall in some of the major food grain-producing states, the balance of water distribution in the country is shifting and it may become more prominent in the years to come. India is already the largest abstractor of groundwater in the world and in the above scenario, there will be tremendous pressure on groundwater in the future. The suggested actions which may counter the looming crisis in the country, particularly in north-western and central Indian states, include increasing forest cover up to 20% in the next 25 years in poorly forested states, limiting area under water-guzzling greenhouse producing gas crops, starting land subsidence survey in cities, limiting groundwater abstraction and injecting water into aquifers, launching group schemes of drip and sprinkler irrigation on a large scale using existing tube-wells/wells, searching the alternative source of wastewater by developing integrated facilities to retrieve, treat, store, and transport wastewater, transferring groundwater from groundwater surplus areas to scarce areas enacting comprehensive central law on groundwater, improving water and agriculture resource efficiency through the Internet of Things, cloud and sensor-based network, mapping and time-bound renovation of large traditional water bodies (>1 hectare), revisiting groundwater assessment methodology and norms, quantifying static groundwater resource, developing heat tolerant and less water consuming crops and changing food habits.