Adaptation by Himalayan Water Resource System under a Sustainable Socioeconomic Pathway in a High-Emission Context

Abstract

Climate change in the Indian Himalayan region is being manifested in the loss of glaciers and altered patterns of monsoon rainfall. Simultaneously, rapid population growth together with economic development are increasing sectoral water demands and changing land use patterns. This study investigated the impact of this complex interplay on water resources in the Beas-Sutlej water resources system. The GFDL-CM3 model was used to describe RCP8.5 future meteorological conditions throughout the 21st century. Population and land use changes were projected under the Shared Socioeconomic Pathway-1 (SSP1). The water evaluation and planning (WEAP) system was applied for assessing sectoral water demands. The results showed increasing runoff during the premonsoon and monsoon seasons due to increased glaciers melting and more rainfall, respectively. It also emerged that irrigation water demand decreased moderately in Punjab (8%–13%) and Haryana (1%–9%); however, the situation was reversed in Rajasthan where it increased by 14%. Adaptation strategies were proposed including increased water allocation to Rajasthan and converting lands to cultivating more staple crops in Punjab and Haryana.