Runoff Simulation In Upstream Of The Wuyuer River Basin Using SWAT Model

Runoff is the basis for the study of water circulation.The study on the response of runoff change in watershed with high vegetation coverage has great reference value for landuse management and water resources allocation,and provides scientific guidance for sustainable development of forests and coping with global climate changing.As an important means of runoff research,hydrological model can establish suitable hydrological models for the area and simulate changes of runoff by inputting a series of hydrological data.Thus,the impact of various factors on runoff were assessed scientifically and systematically.The Wuyuer River is a typical inland river in Northeast China.The vegetation is relatively abundant in the Wuyuer River Basin.The upstream forest coverage rate is high,which is the main runoff producing area and the downstream is wetland.In this study,the hydrological processes at monthly scale were simulated using SWAT(Soil and Water Assessment Tools)in the Wuyuer River Upstream Basin,to explore the applicability of typical rich vegetation cover in northeast China and some results were obtained.1.The R2 and Nash-Sutcliffe for both the model calibration period and the verification period of the single outlet rate were greater than 0.6.Compared with the correction period,the validation period has a certain degree of uncertainty.The single outlet correction for SWAT model can meet the accuracy requirements of runoff simulation.2.The result of double outlet correction is better than that of single outlet calibration.The R2 of the double cutlet and the total outlet of the basin is greater than 0.7.The Nash-Sutcliffe is more than 0.6,and Re reduced to less than 7%.Uncertainty in verification period is lower than that of single outlet calibration.It shows that the SWAT model has a good applicability in the upstream of the Wuyuer River.3.The model has a good overall effect on the simulation of monthly runoff,and can reflect the actual trend of runoff change.The main source of uncertainty in single outlet calibration is the simulation of the peak value of the rainy season.The effect of the double outlet calibrations on the peak value is smaller,and is greatly influenced by the dry water period.4.The parameters analysis shows that the two correction methods are most sensitive to SCS,CN2,CANMX,SOL_BD?ESCO and other parameters.Which explains that the vegetation process and soil water process are closely related to the runoff process of the basin,besides the reason of precipitation.It is the main influence factor on runoff simulation in the upstream of the Wuyuer River.