Study On Response Of Dawen River Runoff Change Environment

The study of runoff response in changing environment has become one of the hot issues in today's society.Climate change and human activities as an important manifestation and component of the changing environment,the river basin runoff changes have brought varying degrees of impact.It is very important to analyze the influence of climate change and human activities on runoff and analyze the contribution rate of both,and it is also a difficult problem in the study of runoff response in changing environment.In this paper,the Dawen River Basin is used as the research area,SWAT model is used to study the sensitivity,analysis and verification of the model.The model is applied to the Dawen River Basin to simulate the runoff change.The main conclusions of this study are as follows:(1)The SWAT model was used to study the watershed,and the watershed was divided into 35 sub-basins and 326 hydrological response units.Sensitivity and uncertainty analysis of the parameters to determine the sensitivity range of the parameters suitable for the watershed.The results show that ENS and R2 are more than 0.6,which are in accordance with the SWAT model.The results show that ENS and R2 are more than 0.6,and the SWAT model is consistent with the SWAT model.The SWAT model can be applied to the watershed.(2)Analyze the changes of climate and precipitation by using Mann-Kendall mutation analysis method and cumulative anomaly method to analyze the trend and change point of annual rainfall and annual mean temperature change in each basin.In 1998,the annual mean temperature of the temperature in the past 26 years was 13.4 ° C and increased by about 0.47 oC / 10 a.The annual precipitation of precipitation was 755.7 mm and about 54.9 mm / 10 a reduced.And provide some reference for the study of river runoff.(3)Analyze the change of annual runoff in the basin under the change of climate scenario.The effect of precipitation change on runoff is higher than that of runoff.Every 10% increase in rainfall,the average runoff increased by about 18.3%.The average runoff is reduced by about 4.1% for every 1 ° C increase in temperature.(4)The runoff changes of land use in the same climatic conditions in 1985,2000 and 2015 were studied respectively.The results showed that the runoff under land use was the largest in 2000,followed by 2015,The smallest is the runoff under land use in 1985.(5)Analysis of runoff rate change under extreme land use scenario shows that the annual runoff value of Scenario 3(grassland)is the largest,followed by Scenario 2(Forest Land)and Scenario I(Cultivated Land)have the lowest annual runoff value.(6)Land use and climate change all lead to varying degrees of variation in runoff,in which land use change is significantly greater than the role of climate change.Approximately 90% of annual runoff changes are caused by land-use change,while climate change affects only 10% of runoff.Therefore,in the future Dawen River Basin water resources management should pay attention to land use trends and take appropriate management measures to promote the Dawen River Basin water ecological environment healthy and sustainable development.