基于CMIP5和VIC模型的长江上游主要水文过程变化趋势预测

Prediction of Major Water Cycle Change over Upper Yangtze River Based on CMIP5 and VIC Model

基于长江上游流域82个气象站点的实测数据和国际耦合模式比较计划第5阶段(Coupled Model Intercomparison Project phase 5,CMIP5)的2种排放情景下的8个气候模式1961～2099年的降水、气温数据,通过等距离累积分布函数法(Equidistance Cumulative Distribution Function Method,EDCDFm)进行气候模式的统计降尺度。在此基础上,构建0.5°×0.5°网格空间分辨率的可变下渗容量水文模型(Variable Infiltration Capacity,VIC),对历史流量进行模拟,并进一步模拟分析长江上游流域2006～2099年径流量、蒸散发的时空演变趋势。结果表明:VIC水文模型能够较好地模拟研究区的水文过程,从长江上游流域未来时期(2006～2099)主要水文过程变化趋势的预测来看,径流量变化趋势不明显、蒸散发呈增加趋势。此研究对于合理规划配置长江流域水资源及为气候影响评价和决策系统提供科技支撑具有重要意义。

Based on the data from the 82 meteorology stations in the upper Yangtze River basin,and the precipitation and temperature data during 1961-2099 of the eight CMIP5 models under two scenario,the statistical downscale study was conducted by using Equidistance Cumulative Distribution Function Method(EDCDFm).On this basis,the Variable Infiltration Capacity(VIC)hydrological model of 0.5°×0.5°grid spatial resolution was built to simulate the historical flow.Furthermore,the spatial and temporal evolution characteristics and trends of the runoff and evapotranspiration in the upper Yangtze River basin from 2006 to 2099 were analyzed.The results show that VIC hydrological model can well simulate the hydrological processes in the study area.According to the prediction of major hydrological process trends in the future(2006-2099)over the upper Yangtze River basin,the trend of runoff change is not obvious while the evapotranspiration is increasing.