Study On The Effect Of Climate Change To Water Resource Using SWAT Model

In recent years, along with the even more serious warming trend and higher frequency of extreme global weather events, many provinces in china sunk into severe drought. And the lack of water has caused serious damages on people’s lives and economy. Study the impact of climate change on water resources, therefore, has important significance to help government reasonably scheduling water resources and to help ensure the safety of local water using. With the help of RS and GIS, this paper studied the change of water resources in Kaidu River Basin and analyzed the impact of climate changing to local water resources by using SWAT hydrological model.Getting land use and soil data by using visual interpretation and mathematical statistics methods, and establishing the weather generator using measured meteorological data from1988to2009. Then, this article established the parameters database with the help of GIS. On this basis, this paper, using SWAT model, simulated the runoff of Kaidu River Basin and discussed the response characteristics of runoff to different climate changing conditions. The result of simulation would be validated by the measured runoff data form1990to2009. The article is mainly got the following conclusions:(1) Established SWAT distributed monthly runoff model of Kaidu River Basin, and the simulation result was credible and consistent with the measured runoff. During the calibration period (1990-2000) the Nash-suttcliffes coefficient is0.58, and the average Relative Error and Linear Fit are-5.7%and0.8, while the result of validation period (2000-2009) was close to calibration period. Totally speaking, the simulation result was lower than the measured value, but still within the error range.(2) Seasonal snowmelt is an important component of the study area runoff. Based on the characteristics of the study area, this article had identified the snow/snowmelt parameters, aid to improve the accuracy of the winter and spring runoff simulation.(3) Seven most sensitive parameters to runoff simulation had been found through sensitivity test. To make runoff simulation result be closer to the measured runoff, this paper combined automatic calibration and manual calibration method to obtain the optimal value of those seven parameters.(4) This article assumed future climate changing scenarios to research the response of runoff to climate change in Kaidu River Basin, found that the annual average runoff was positively correlated with precipitation and was negatively correlated with temperature. The result also showed that precipitation change played a more important role on impacting local runoff than temperature. And this indicated that the main impact factor driving future annual average runoff changing is precipitation.(5) Study the impact of climate change on runoff process during the year, found when the temperature is constant and the precipitation is increasing, runoff showed the same trend as precipitation by different rates. If the precipitation unchanged, and the temperature is gradually increasing, the runoff would be decreased in each month except months in spring.This study can provide references for runoff simulation in arid and semi-arid inland river region, and can provide data and technical supports for local government in water resource management and prevention of drought and floods.