Runoff evolution characteristics and influence factors in the Datong River Basin
Datong River Basin is an important source for water diversions in Qinghai and Gansu Province.With a sensitive and fragile ecological environment,the identification of the attribution of runoff changes is crucial to the development and management of regional ecological environment and water resources.The methods such as climate tendency rate,cumulative anomaly,sliding t test,and Hurst index were adopted to explore the evolution of meteorological and hydrological elements in Datong River Basin from 1961 to 2020,and the main influencing factors of runoff changes were quantitatively assessed using hydrothermal coupling balance equation and accumulation slope change rate based on the Budyko hypothesis.The results showed that the climate in the Datong River Basin had become significantly warmer and more humid in the past 60 years,with temperatures and precipitation trends of 0.39℃‧(10 a)-1 and 9.1 mm‧(10 a)-1 respectively,and the trend was expected to continue for some time to come.The abrupt change in the annual runoff occurred in 1990,with an increase in the upstream and a significant attenuation in the middle and downstream.Due to the influence of reservoir regulation and storage,the proportion of runoff decreased during the flood season,and the annual distribution tended to be balanced.The Datong River Basin was mainly of grassland,and the land use and vegetation coverage remained unchanged during the research period.The glaciers were severely shrinking in the region,with a reduction of 20.9 square kilometers in area and 2.99 thousand cubic meters in storage.The annual melted volume of the glacier was 37 million cubic meters,accounting for approximately 1.3%of the runoff.Climate change was the force behind the increase in upstream runoff,the effect of precipitation was much greater than that of evaporation and temperature.Interbasin water transfer is the dominant factor of the reduction of runoff in the middle and lower reaches,with a higher impact on the middle reaches than on the downstream.
Datong River Basinrunoff evolution attributionelastic coefficient methodslope change rate method of cumulantland use
万方数据
维普
