| Abstrakt: |
The inland river basin in Hexi, Gansu Province, is extremely short of water resources. There are certain differences in the changes of mountain runoff between the central and western and eastern water systems in the basin. Studying the changes in mountain runoff and the contribution rates of different factors is of great significance for ensuring the sustainable development and utilization of regional water resources. Based on the data of mountain runoff and precipitation and temperature in the main runoff producing areas from 1956 to 2021, various trends and mutation tests, cumulative slope change rate methods, and combined with the characteristics of runoff supply, the changes in mountain runoff and their responses to changes in precipitation and temperature in the three major water systems were analyzed. The results show that: 1 the average annual mountain runoff of the Shiyang River system was 1.36 billion m³, showing a non-significant decreasing trend over the years and a non-significant increasing trend in precipitation, The significant increase in temperature leads to an increase in evaporation, resulting in a decrease in runoff; 2 The average annual runoff from the Heihe River system has increased from 3.062 billion m³ before the mutation point in 2006 to 3.56 billion m³ after the mutation point. The contribution rate of precipitation to runoff changes is 16.7%, and the temperature has significantly increased, enhancing the impact on runoff changes; 3 The average annual runoff from the Shule River system has increased from 1.422 billion m3 before the mutation point in 1998 to 17.93 m3 after the mutation point. The impact of precipitation and temperature on runoff changes is similar, with contribution rates of 30.4% and 30.2%, respectively. There are certain differences in run-off supply characteristics and climate conditions among the three major inland river systems in Hexi, resulting in inconsistent responses of runoff to different driving factors. [ABSTRACT FROM AUTHOR] |
