Combined effect of landuse/landcover and climate change projection on the spatiotemporal streamflow response in cryosphere catchment in the Tibetan Plateau

Abstract

Climate and landuse/landcover (LULC) change are primary drivers significantly impacting basin hydrology. However, in the Tibetan Plateau (TP), future streamflow projections that consider the combined effects of climate change and LULC change are lacking. This study aims to enhance the accuracy of future streamflow simulations in the Lhasa River Basin (LRB). It is the initial attempt to evaluate future streamflow variation in the TP that considers the sensitivity of crucial hydrological components (snow, glacier, and permafrost) to warming trends, along with future LULC changes and bias-corrected climate projections. Using the Water Balance Simulation Model (WaSiM), we assessed the individual and combined impacts of climate and LULC change on spatiotemporal streamflow variations from 2010 to 2099 in the LRB. The model includes the entire cryosphere component, essential for regions like the Tibetan Plateau. Future LULC patterns were predicted using the Cellular Automata-Markov model, while multiple bias-corrected General Circulation Models (GCMs) provided climate change data under two emission scenarios. Results suggest urban areas may expand to 83.9% by 2090 compared to 2020. Future precipitation and temperature trends in the LRB indicate an overall increase, except for a decline in winter precipitation. The impacts of LULC change and climate variability on streamflow differ among sub-basins. LULC change alone could lead to a 7.01% annual streamflow increase, while future climate change may increase annual streamflow by 7.37% to 71.74% compared to the baseline (1980–2009). When both drivers are combined, streamflow increases are projected to range from 9.53% to 82.36%. Although LULC change is a lesser factor, its implications in streamflow projections in TP should not be overlooked. The findings of this study can assist policymakers in managing the challenges posed by climate and LULC change in the LRB.