Abstract:

Based on meteorological and hydrological data from the Danghe river basin spanning 1966 to 2022, the β−Z−H three-parameter comprehensive indicator method, M−K test, Budyko hydrothermal coupling balance equation and Pearson correlation analysis were employed to analyze the evolution characteristics of hydrological and meteorological elements in the basin, quantify the contribution of climate change and human activities to changes in runoff, as well as the response of runoff to climate change under various scenarios. The results indicated that: (1) from 1966 to 2022, annual precipitation, runoff and average temperature in the Danghe river basin exhibited significant increases, with rates of 10.57mm·10y⁻¹, 0.21×10⁸m³·10y⁻¹ and 0.39℃·10y⁻¹, respectively, while potential evapotranspiration increased at a slower rate of 2.44mm·10y⁻¹. (2) The annual runoff at the Dangchengwan station experienced an abrupt change in 1982. Compared to the base period (1966−1982), the average runoff during the change period (1983−2022) increased by 0.73×10⁸m³, with climate change identified as the primary influencing factor, contributing 58.22%. (3) Among the climate change factors, precipitation and average temperature were found to be the main driver of runoff changes. Under a climate scenario projecting an increase of 2.5°C in average annual temperature and a 20% rise in annual precipitation, the annual runoff depth change rate for the Danghe river basin was estimated at 23.66%. These research findings provide a theoretical basis for the integrated management of water resources in the Danghe river basin and for the sustainable development of the Dunhuang oasis.

Key words: Danghe river basin, Budyko hypothesis, Climatic factors, Human activities, Climate scenario assumption