敦煌大泉河径流量24小时变化规律分析

small river named Daquan river flowing by Mogao Grottoes was selected as the researching object of this study. Based on the monitoring of runoff, evaporation capacity and air temperature and humidity, the relationship between the twenty-four-hour runoff variation of the south Mogao Grottoes cross section of this river and meteorological elements was analyzed in this paper. It was found that the runoff variation curve was “S” in shape, strong evaporation was the root cause of the significant runoff variation, and runoff loss due to strong evaporation accounted for 24%～37% of the gross diurnal runoff. Understanding this natural law not only has great significance in explaining the hydrological cycle of inland river basin in arid area, but also has practical application value in rational exploitation and utilization of water resources and reducing useless evaporation.