439 / 2024-03-18 08:51:22

Reconstruction of runoff in the source region of the Yangtze River based on the ice core records of the Qinghai-Tibet Plateau

runoff; water resources; ice core records; Qinghai-Tibet Plateau; source region of the Yangtze River

Subtheme 5: Climate Change: Adaptation, Mitigation and Resilience > Topic 1: Hydrology and Water Resources response to climate change

The runoff conditions of rivers in the source region of the Yangtze River have changed significantly in recent decades. The study of the characteristics of runoff changes in the Yangtze River source area under the background of global warming is of great practical significance for understanding the hydrological effects caused by climate change. In this paper, the measured hydro-meteorological data from 1960-2019 at the Tuotuo River hydrological and meteorological stations were used to analyze the evolution of runoff and its relationship with meteorological factors such as precipitation, temperature, and evaporation. The δ¹⁸O records and ice core accumulation of five ice cores from the Qinghai-Tibet Plateau were used to analyze the relationship between δ¹⁸O records and ice core accumulation among different ice cores, and the correlation between ice core records and the runoff of the Tuotuo River. On this basis, the 10-year moving average runoff series during 1900-1960 at the Tuotuo River hydrological station was reconstructed, and the high and low water variation patterns of Tuotuo River runoff over 100 years were preliminarily analyzed. The results show that the annual runoff of the Tuotuo River Hydrological Station has a significant increase trend around 2002, and the increase in glacier and snowmelt water caused by the sharp rise in temperature in the source region of the Yangtze River is one of the important reasons for the sharp increase in flow in this region. The reconstruction of the runoff series of the Tuotuo River since 1900 shows that the Yangtze River source area has experienced several alternating high and low water changes, and the runoff change pattern basically coincides with the three sudden climate change time points on the Qinghai-Tibet Plateau. The results of the study provide a reference for revealing the evolution of river runoff patterns and its hydrological response in the source region of the Yangtze River under climate change conditions.