Abstract:

Future climate changes and its influences on water resources in Hanjiang River basin concerns the exploitation and benefit of both SouthtoNorth water diversion and Han River project.Therefore, it is very important to analyze the characteristics of water resources in response to climate changes for providing scientific foundation to ground water diversion,exploiting water resources in the air,dealing adverse effect of climate changes and protecting the water sources areas in middle line of SouthtoNorth water diversion.Years 1971～2000 were set as the base period,and monthly runoffs were simulated using SWAT in the base period in Hanjiang River basin.Based on the accurate runoff simulation of the base period,the authors simulated each possible water resources situation under 25 climatechange scenarios according to the most possible climate change predictions in Hanjiang River basin.Change rates of water resources under 25 climatechange scenarios were obtained,and then hydrological responses of Hanjiang River basin to possible climate changes were studied.The result shows:the precision of SWAT simulation is higher than the criterion(〖WTBX〗Ens>05，r2>06〖WTBZ〗)after the calibration, and SWAT is applicable to simulate the runoff in Hanjiang River basin;under the 25 different climatechange scenarios,runoff changes are more obvious than evapotranspiration;surface runoff and base flow would be more sensitive to variations in precipitation than to variations in air temperature;evapotranspiration would be more sensitive to variations in air temperature than to variations in precipitation;when precipitation increases or air temperature decreases,the runoff would increase;when precipitation increases or air temperature increases,the evapotranspiration would increases.

Key words: Hanjiang River basin/ SWAT model/ runoff simulation/response to climate change