Hydrological response to future climate change in a mountainous watershed in the Northeast of Tibetan Plateau

Abstract

Study regionUpper reach of the Heihe River basin (UHRB) Study focusWe quantified the potential changes in future climate and streamflow, as well as their corresponding contribution to the annual variations. And the dominant factors of streamflow change were explored in further. Robust multivariate bias correction was applied to correct the outputs of the general circulation method (GCMs) before applying the climate projection. The Soil and Water Assessment Tool model was applied to explore streamflow characteristics under the climate projection of bias-corrected GCMs under four representative emission scenarios (SSP1–2.6, SSP2–4.5, SSP3–7.0, and SSP5–8.5). New hydrological insights for the regionBy the end of the 21st century, climate will follow a warming and wetting trend within the basin; the annual streamflow is projected to increase by > 18 % in the 2030 s, and > 36 % in the 2050 s and 2090 s. Overall, the minimum temperature had a positive impact on streamflow in the cold seasons, especially in spring, contributing the most to the annual streamflow increment. When the temperature increase is greater than 5.42 °C, the peak streamflow will shift forward from May to April. Moreover, evapotranspiration will increase with temperature, leading to a decrease in summer streamflow. The results enable us to better understand the climate and streamflow changes at different time scales and provide guidance for the development of climate change response strategies and water resource management planning.