海河流域河川径流对气候变化的响应机理

Response of runoff to climate change in the Haihe River basin

利用可变下渗容量(Variable Infiltration Capacity,VIC)模型,在海河流域选取了6个典型流域来率定VIC模型的参数。通过模型参数移植技术,建立了全流域的径流模拟平台。根据假定的气候变化情景,分析了海河流域河川径流对气候变化的响应机理。结果表明:在年平均气温升高2℃时,海河流域的径流量将减少6.5%;当年降水量增加或者减少10%时,海河流域的径流量将分别增加26%和减少23%;当汛期降水占年降水量的比例分别增加或者减少10%时,全流域的径流量将会增加12%或者减少7%;在空间上,在年平均气温升高和年降水量变化的情景下,海河流域西北部的河川径流比东南部更敏感;在降水年内分配变化的情景下,海河流域东南部的河川径流比西北部更敏感。总体上,年降水量越大,径流量对降水量的敏感性越小,对平均气温的敏感性也越小,而对降水年内分配的敏感性越大。

The Variable Infiltration Capacity（ VIC） model was used to investigate the response of runoff to climate change in the Haihe River basin（ HRB）. Firstly,the parameters of the VIC model were calibrated in six sub-catchments in the HRB. Secondly,using the parameter regionalization methodology,the model parameters were estimated in other parts of the HRB. Thirdly,The response of runoff to climate change in the HRB was estimated based on the hypothetical climate scenarios. The results indicated that a 2℃ increase of annual mean temperature would lead to a6. 5% decrease of runoff in the HRB. A 10% increase or decrease of annual precipitation would lead to a 26% increase or 23% decrease of runoff,respectively. A 10% increase or decrease of the percentage of precipitation in the flood season would lead to a 12% increase or 7% decrease of runoff,respectively. Spatially,under the change of temperature and / or precipitation,the runoff in the north-western HRB was more sensitive than that in the south-eastern HRB. Otherwise,under the change of the percentage of precipitation in the flood season,the runoff in the southeastern HRB was more sensitive than that in the north-western HRB. Overall,the more precipitation,the less sensitive of runoff to precipitation and / or temperature,but the more sensitive of runoff to the percentage of precipitation in the flood season.