Groundwater rejuvenation in parts of India influenced by water-policy change implementation

Soumendra N Bhanja,Isabella Velicogna,Matthew Rodell,Kishore Pangaluru,Yoshihide Wada,Abhijit Mukherjee,Siddhartha Chattopadhyay,James S Famiglietti

doi:10.1038/s41598-017-07058-2

Abstract

The dwindling groundwater resource of India, supporting almost one fifth of the global population and also the largest groundwater user, has been of great concern in recent years. However, in contrary to the well documented Indian groundwater depletion due to rapid and unmanaged groundwater withdrawal, here for the first time, we report regional-scale groundwater storage (GWS) replenishment through long-term (1996–2014, using more than 19000 observation locations) in situ and decadal (2003–2014) satellite-based groundwater storage measurements in western and southern parts of India. In parts of western and southern India, in situ GWS (GWSobs) has been decreasing at the rate of −5.81 ± 0.38 km3/year (in 1996–2001) and −0.92 ± 0.12 km3/year (in 1996–2002), and reversed to replenish at the rate of 2.04 ± 0.20 km3/year (in 2002–2014) and 0.76 ± 0.08 km3/year (in 2003–2014), respectively. Here, using statistical analyses and simulation results of groundwater management policy change effect on groundwater storage in western and southern India, we show that paradigm shift in Indian groundwater withdrawal and management policies for sustainable water utilization appear to have started replenishing the aquifers in western and southern parts of India.

Highlights

Groundwater is the largest liquid freshwater resource of the Earth
We used robust statistical approaches and a global-scale hydrological model simulation results in order to show the influence of water management policy change in replenishment of groundwater storage in western and southern parts of the country
We tried to understand the potential effects of these policy changes on groundwater storage anomaly in Gujarat between 1996 and 2012 by using first-order Bayesian Vector Autoregression (BVAR)

Summary

G WSi n H have bee n

3, at a r at e of 4. 5 5 ± 0. 1 1 k m 3 / y e ar a n d 3. 5 9 ± 0. 1 4 k m 3 / y e ar, r es p e cti v el y ( Fi g. 2 ). H es e o bs er v ati o ns ar e i n a gr e e m e nt wit h pr e vi o us i n sit u o bs er v ati o ns o v er I G B b asi n ( d e pl eti o n at a r at e of ~ 8 k m 3 / y e ar b et w e e n 2 0 0 0 a n d 2 0 1 2)1 7 , a n d s at ellit e- b as e d o bs er v ati o ns of GWSde pl eti o n fr omthegener al ar e as, e. We tried to understand the potential effects of these policy changes (reduction of agricultural electricity usage, AEU) on groundwater storage anomaly in Gujarat between 1996 and 2012 (based on data availability) by using first-order Bayesian Vector Autoregression (BVAR). The PCR-GLOBWB simulations are extended for two more years i.e. 2013 and 2014 using the values of 2012

Conclusions

Findings

Methods