Modelling water levels of northwestern India in response to improved irrigation use efficiency

Shashank Shekhar,Shive Prakash Rai,Suneel Kumar Joshi,A L Densmore,Suman Kumar,W M Van Dijk,Dewashish Kumar,Manoranjan Kumar,Rajiv Sinha

doi:10.1038/s41598-020-70416-0

Abstract

The groundwater crisis in northwestern India is the result of over-exploitation of groundwater resources for irrigation. The Government of India has targeted a 20 percent improvement in irrigation groundwater use efficiency. In this perspective, and using a regional-scale calibrated and validated three-dimensional groundwater flow model, this article provides the first forecasts of water levels in the study area up to the year 2028, both with and without this improvement in use efficiency. Future water levels without any mitigation efforts are anticipated to decline by up to 2.8 m/year in some areas. A simulation with a 20 percent reduction in groundwater abstraction shows spatially varied aquifer responses. Tangible results are visible in a decade, and the water-level decline rates decrease by 36–67 percent in over-exploited areas. Although increasing irrigation use efficiency provides tangible benefits, an integrated approach to agricultural water management practice that incorporates use efficiency along with other measures like water-efficient cropping patterns and rainwater harvesting may yield better results in a shorter period.

Highlights

The groundwater crisis in northwestern India is the result of over-exploitation of groundwater resources for irrigation
Using data from the Central Groundwater Board (CGWB), the nodal agency of the Government of India responsible for groundwater affairs, and state groundwater boards, we estimate that the average canal water released for irrigation in the study area is only about 32 percent of the groundwater abstraction
How will the aquifer response to improved irrigation efficiency vary across different parts of the study area? To answer these questions, we modelled the regional groundwater system with the following main objectives: 1. Determine how groundwater levels will change in the decade (2020–2030) at the present rate of groundwater abstraction; and

Summary

Introduction

The groundwater crisis in northwestern India is the result of over-exploitation of groundwater resources for irrigation. Asoka et al.[16] and van Dijk et al.[13] argued that changes in groundwater storage in northwestern India are primarily controlled by pumping rather than by precipitation v ariation[13,16] To address this crisis, the Government of India has recommended a 20 percent improvement in irrigation groundwater use efficiency[17,18]. The Government of India has recommended a 20 percent improvement in irrigation groundwater use efficiency[17,18] This recommendation is based on recent research which shows that 23–49 percent increases in efficiency can be achieved through alternative irrigation methods (such as sprinkler, drip, alternate wetting/drying approaches), with no loss in yield[19,20]. How will the aquifer response to improved irrigation efficiency vary across different parts of the study area? To answer these questions, we modelled the regional groundwater system with the following main objectives: 1. Determine how groundwater levels will change in the decade (2020–2030) at the present rate of groundwater abstraction; and

Methods

Results

Conclusion