用耦合模型模拟青弋江流域水文对气候变化的响应

用陆面模式SSiB与动态植被模型TRIFFID以及流域地形指数水文模型的耦合模型SSiB4T/TRIFFID模拟了长江下游的青弋江流域植被和水量平衡的动态过程,分析了气温和降水变化对流域径流和蒸发的影响。结果表明：（1）流域气温上升10C,径流减小6.7-9.7%;气温上升20C,径流减小11.7-17.4%;（2）降水增加5%,径流增加9.2-11.6%,降水减小5%,径流减小8.6-11.6%;（3）温度不变仅降水变化对流域蒸发影响很小,温度增加20C,流域总蒸发3-10月份增加8.0-10.7mm,其余月份增加5.4-7.1mm,1月和12月蒸发对温度增加最敏感;（4）气温上升20C,叶面积指数1月和12月增加,5-10月略有减小。降水和气温变化对青弋江流域径流影响明显且与植被类型有关,流域蒸发的变化主要受温度变化的控制。

Hydrological Responses of Qingyijiang Basin to Climate Changes

Basing the coupled model(SSiB4T/TRIFFID) of Land surface model SSiB4T,Plant dynamic vegetation model TRIFFID and basin topographic index of hydrological model(TOPMODEL),the dynamic process of vegetation and water balance in Qingyijiang basin was simulated to analyze the impact of temperature and precipitation on watershed runoff and evaporation.The results show that(1) The temperature increases 10C(20C),the watershed runoff will decrease 6.7% to 9.7%(11.7% to 17.4%);(2) The precipitation increases(decreases)5%,the watershed runoff will increase(decrease)9.2-11.6%(8.6-11.6%).(3) Constant temperature with precipitation variation have little effect on the watershed evaporation.When temperature rises 20C monthly total evaporation of the basin increases 8.0to 10.7mm(5.4 to 7.1mm) from March to October(during rest of the year).In January and December,evaporation is the most sensitive to temperature increase.(4) Leaf area index increases significantly in January and December,while slightly decreases in the month from May to October.The total runoff of the basin is sensitive to temperature and precipitation changes,and related with types of vegetation cover.The variations of evaporation are mainly controlled by that of temperature.