Water balance approach to study the effect of climate change on groundwater storage for Sirhind command area in India

Abstract

Continuous over-exploitation of groundwater resources has severely curtailed the resilience of their aquifers and their ability to stabilize farming livelihoods in the face of heightened hydro-climatic variability. Groundwater in Punjab region is pumped from great and increasing depths, causing decline in groundwater storage which affects crop production. In this study, an investigation is carried out to evaluate the impact of climate change on groundwater storage for Joga distributary of Sirhind command area which falls under Satluj basin in India. In this analysis, observed gridded data and Regional Climate Model simulated data for mid-century and end-century period have been used for climate study. Initially, a statistical analysis is implemented to detect the trend available in precipitation and evapotranspiration data. Seasonal variation of different climate parameters shows that rainfall may increase nearly 30% by the end of the century compared to the current climatological baseline during the monsoon period. The whole basin is projected to warm significantly, with minimum temperatures rising most pronouncedly.Water Evaluation and Planning (WEAP) model has been used to estimate the groundwater storage. Different scenarios are developed using the WEAP model; analysis shows that a shift to direct seeded rice, along with improvement in irrigation efficiencies, would improve the sustainability of groundwater use. Reducing the area planted with rice by 25% almost restores the system to sustainable groundwater use. Cost analysis indicated that the cost per hectare for groundwater irrigation with direct seeded rice and a reduced area would be about 2670 Rs/ha.