Spatiotemporal analysis of ENSO-IOD teleconnections and GCM-projected hydroclimatic shifts in a western Himalayan basin

ABSTRACT The extreme event analysis has substantial implications for water resources since it highly impacts the agrarian economy of regions in the north-western Himalayas. This research aims to examine the precipitation patterns in the flood-prone basin of the river Beas using various global climate models (GCMs) from Climate Model Intercomparison Project Phase 6 (CMIP6). In this study, various homogeneity tests, i.e. Pettitt's tests, Standard Normal Homogeneity Test (SNHT), Buishand's, Von Neumann tests for change point detection and for trend analysis tests, i.e. modified Mann–Kendall (mMK), Sen's slope (Q), and innovative trend analysis (ITA) techniques have been used to examine rainfall patterns across the Beas basin. The multi-model ensemble (MME) results indicates a basin-wide increase in annual precipitation ranging from 0 to 5% under SSP1-2.6, 8 to 15% under SSP2-4.5, 18 to 32% under SSP3-7.0, and up to 28 to 45% under SSP5-8.5 by the end of the century, with the strongest historical teleconnection signals observed during the pre-monsoon season where positive Indian Ocean Dipole (IOD) phases account for 30–35% correlation with rainfall variability. The results of this study bear a substantial implication for policymakers and water resource managers in the western Himalayan region.