Response Of Runoff To Environment Change In The West Of Tianshan Mountain

Because of the excessive emissions of greenhouse gases, the climate warming has been on the list, theclimate change has a profound impact on river basin water resources for a century. The impact of humanactivities on water resources in the basin mainly through the change of land use pattern to change withinthe catchment runoff mechanism. The influence of runoff on the study of climate change and Land Use/Land Cover Change (LUCC) has been the two scientific research on hydrological research.Kahai River is the second largest tributary on Yili river, it located in the western tianshan mountains，content mainly in the glacier, snow, rain and snow mixed groundwater recharge.This research takes KahaiRiver of Yili as the research object, which based on hydrological model SWAT, Study Based on the1990-2000urras stations daily runoff data for parameter calibration and validation, the results show thatNSH coefficients are all above0.78and the change process of runoff can be better reflected and can be as abasic model of forecast.The different impacts has been analysised on the runoff scenarios assumed which by setting theclimate change and Land Use/Land Cover Change in different scenarios, the main contents andconclusions of the research are as follows:By setting different climate scenarios, The results showed that: Temperatures has greater impact on theKashi River runoff.the catchment runoff of Kahai River is positively correlated with rainfall.The rainfallremains unchanged while the temperature increased by1and2, the average amplification of runoff is3.35%and5.41%respectively; while the temperature reduced by1and2, the average amplification ofrunoff is-4.71%and-9.89%respectively. The temperature remains unchanged while the rainfall increasedby10%and20%, the average amplification of runoff is7.33%and14.66%respectively, while the rainfallreduced by10%and20%, the average amplification of runoff is respectively-7.60%and-15.65%.Theinfluence of rainfall change on catchment runoff of Kahai River is greater than the temperature change on it.The temperature remains unchanged while the rainfall increased by20%, the average amplification ofrunoff is14.66%, The rainfall remains unchanged while the temperature increased by2, the averageamplification of runoff is5.41%,which less than half of the average amplification of runoff when therainfall increased by20%. Therefore, The influence of rainfall change on catchment runoff of Kahai Riveris greater than the temperature change on it.The simulation scheme of Land Use/Land Cover Change is: according to the land use data has beencompleted and to the graphs of land use in1980and2000, the two situational of Land Use/Land CoverChange are established which based on the constant of climatic factor.The results show that: the80s and2000land use map used to simulate, and the relative error of thesimulated and measured mean annual average runoff volume is-1.51%and-1.57%respectively. Thecalculated results are approaching to the observed data of the two graphs of land use, there is no heavychange on runoff when the land use type is different. The main factors influencing runoff is the climatechange of Kahai River,which is significantly higher than that of Land Use/Land Cover Change.