气候变化对祁连山石羊河出山口径流的影响研究

Impact of Climate Change on Runoff of Shiyang River in the Qilian Mountains

根据近50a来石羊河流域上游祁连山山区的气温、降水及出山径流观测数据,用遗传算法和自动寻优-人机对话法,建立了出山径流对于气温、降水变化的响应模型,并以该模型为基础,初步预测了石羊河流域上游山区未来气温、降水的变化趋势以及该气候情景下出山径流的相应变化.结果表明:未来数十年间,山区气温仍呈缓慢的上升趋势,山区降水变化总体趋势是下降的,但下降幅度不大.受山区气温、降水变化的影响,未来出山径流亦呈下降的趋势,下降幅度主要取决于山区降水减少的幅度.

According to observational data of temperature,precipitation and runoff during recent 50 and more years in the upper reaches of the Shiyang River Basin of Qilian Mountains,we employ genetic algorithms and automatic optimization method,the man-machine dialogue method,to build models of runoff response to temperature,precipitation changes,and then using the models,we predict changes in runoff from the corresponding changes in the upper reaches of the Shiyang River Basin mountain based on change trends of temperature and precipitation as well as the climate scenarios in future.The results showed that temperatures are still slowly raising trend,and precipitation in the overall trend is down in area of the mountain in the next decades,but precipitation decrement was not remarkable.In situation of future air temperature and precipitation change in mountain,runoff from mountain was also a decreasing trend in the future,but the runoff decline magnitude depends on the rate of decrease of mountain precipitation.