Unravelling the elevation-dependent warming in the Indus Basin

Abstract

The Elevation Dependent Warming (EDW) in the mountain regions have wider implications to its cryosphere, hydrological, and ecological systems. This paper explores an EDW in the Indus River Basin, considering Jhelum, Kabul, and Indus sub-basins to improve the accuracy and understanding of cryospheric and hydrological changes in the basin. We use the maximum (Tmax), minimum (Tmin), and mean (Tmean) near surface atmospheric temperature data from 21 ground stations for the 1988–2021 period and applied the Mann-Kendall (MK) trend tests for exploring the trends in the data. The results show that Tmax and Tmin has significant (p < 0.001) warming trends in the Upper Indus Basin (UIB) until 2210 mean above sea level (m asl). Tmax has increased with a rate of 0.031 °C yr−1 (p < 0.001) while Tmin increased with a rate of 0.029 °C yr−1 (p < 0.001), hence the “diurnal temperature range (DTR) also increased significantly” (0.015 °C yr−1, p < 0.001). In this study, a symmetric pattern of increasing trends has been observed in Tmax and Tmin. Moreover, Tmax has increasing trends throughout the period in the middle and high-altitude regions, except in Autumn and Monsoon seasons, respectively. While more significant and prominent increasing trend observed in Tmax during the winter season. Thus, this consistent warming trends in all seasons with more prominent trend in the winter season for Tmax can have harmful impact on the cryosphere of the region and ultimately, leading to water scarcity and extreme droughts.