Study On Runoff Simulation To Yeerqiang River Basin In Kunlun Mountains

Yeerqiang River originated from Kunlun Mountains is one of the three major headstreams. With the process of ecological restoration and construction of the Tarim River, flood forecast of glacier lake break and runoff process is extremely urgent. As a main tool of runoff formation simulation and flood forecasting, watershed hydrological model plays an important role in flood protection.Glacier melting is the important part of the runoff formation in Xinjiang. So adding snowmelt module to watershed model is necessary when watershed model was applied in the River of Xinjiang, and its calculation accuracy directly affects runoff simulation accuracy. Xin'anjiang watershed model containing snowmelt structure has been applied in Tianshan Mountains, and gains better effect. Compared with Tianshan Mountains, drainage basin height differences of Kunlun Mountains basin and glacier/snow melt water ration to runoff are both much larger, while the position of actual metrical hydrological stations is low, especially the distribution information of air temperature distribution, precipitation distribution, and so on, is still lacking, which is an obstruction to carry out runoff forecast research to high-cold mountains.It estimates precipitation distribution based on the recent research achievements of precipitation distribution in mountain region and the precipitation distribution in Kunlun Mountains. In view of air temperature is an important input variable in snowmelt calculation; the temperature plays the leading role to runoff in the rivers which supplemented with melted snow and glacier water. Therefore, runoff simulation accuracy depends greatly on the estimation accuracy of vertical distribution of air temperature. By virtue of sounding temperature from the weather station in the vicinity of the research areas to compensate for the lack of temperatures data in mountains, three calculation methods are designed in order to estimate vertical distributions of the air temperature in high-cold mountains.This article take Yeerqiang River Basin as the example, the drainage networks were extracted based on the grid DEM data(90m×90m),and then the simulated area is divided into 7 belts by elevation. Adopting before-mentioned information and data processing method, utilizing the Xin'anjiang watershed model containing snowmelt structure to conduct daily runoff simulation, and achieve the good results. The results show that this model is applicable to Yeerqiang River Basin, considering variational characteristic of zonal temperature, precipitation and evaporation with the elevation change is reasonable, which accord with reality of the basin. The calculated temperature lapse rate with sounding air temperature can reflect the vertical variation rules of the air temperature in high-cold areas in a certain space range, and could be used in the runoff simulation of inland rivers lacking of data.This study has practical value for establishing hydrological forecasting system and water resource planning in Kunlun Mountains.