1990-2007年贡嘎山海螺沟径流变化对气候变化的响应

Response of Runoff Variation to Climate Change in Hailuogou Drainage Basin in Gongga Mount in 1990-2007

使用1990—2007年近20 a的径流和相应的降水、温度等资料,对贡嘎山东坡海螺沟冰川河年径流与季节径流对气候变化的响应进行分析.结果表明:年径流与季节径流对气候因子的敏感性不同,各个季节径流对气候因子的敏感性也有差异.平均地温逐年升高是海螺沟年平均径流量增加的关键因素,相对影响力为77%,降水因子占23%.春季径流量的增加归因于平均最低气温的升高,其影响程度为68%;温度同样是影响夏季径流的主要因子,平均最低气温,平均日较差相对影响程度分别为34%、31%;降水量增多、平均地温升高是秋季径流量增加的主要原因,相对影响程度分别是35%、65%;影响冬季径流的主要气候因子是冬季平均最低气温、平均地温,影响程度分别是36%,64%.温度是影响冰川径流季节和年际变化的共性主导因素,气温升高及其导致的地温显著增加是海螺沟径流增加的主要原因.

Based on the data of r.unoff and the corresponding precipitation and temperature in 1990-2007, the response of annual runoff and seasonal runoff variations to climate change in Hailuogou drainage basin in the eastern slopes of Gongga Mount is analyzed using the Principal Component Regression Analysis method. The results indicate that： the sensitivities of annual runoff and seasonal runoff to climate change are different, and there are differences among different seasons. The rising of mean ground temperature year by year is the key factor of the increase in annual runoff from Hailuogou drainage basin year by year, with a relative in fluence of 77%, while the influence of precipitation is 27%. The increase in spring runoff can he attributed to the rising of mean minimum temperature, whose relative influence is 68%. Tempera-ture is also a main factor affecting the summer runoff, and the relative influences of mean minimum temperature and averaged diurnal temperature range are 34%, 31%, respectively. The increase in autumn runoff can be attributed to the increasing autumn precipitation, the rising of mean ground temperature, with the influences of 35% and 65% The change of winter runoff is related to the mean minimum temperature and averaged diurnal temperature range, and their relative influences are 36%,64%, respectively. Temperature is the common leading factor of the seasonal and annual variations of glacial runoff, and the air temperature rising and the ground temperature rising caused by air temperature are the main reason of runoff increasing in the Hailuogou drainage basin.