SWAT runoff simulation and predictions in Liyuan River basin of Gansu Province

Data regarding to Liyuan River basin were collected to establish a data-base.Then,a physically based distributed hydrological model(SWAT) was used to simulate the surface runoff from 1990 to 1999 on the basis of this data-base.After that,the analog value was compared with the actual one,we could get the results that the relative error is less than 10%,the correlation and Nash-Sutcliffe coefficients are both above 0.80.It indicated that the established SWAT model can be applied to the surface runoff simulation of Liyuan River basin.Lastly,meteorological data predicted by auto-regressive model and time domain analysis is added to SWAT model to predict surface runoff of the years(2009-2018).The results show that there is an apparent downtrend of runoff during this period.Through analying the response of the runoff to climate changes,it is found that the response of runoff to temperature is more sensitive than that of runoff to precipitation.