贡嘎山东坡不同流域河川径流特征对比分析

Comparative Analysis on the Annual Runoff Characteristics of Different Basins in the Eastern Slope in Gongga Mountain

选取贡嘎山东坡海螺沟流域冰川河和森林区不同尺度3条沟,结合最近10余年的径流和相应的降水、温度等资料,运用径流分割、相关分析等方法对相邻的冰川区和森林区河川径流组分、年内分配、年际变化进行对比分析。结果表明:海螺沟冰川河是冰川融水(50.1%)、地下水(27.9%)、降水(18.2%)混合型补给的河流,6～9月径流组分主要是冰川径流(62.3%)和降雨径流(22.7%),枯季径流主要成分是地下水(67.9%)和融雪径流(22.55%),年内分配不均匀系数为0.76;森林区河沟枯季以地下水补给为主,湿季以降水补给为主,黄崩溜沟和马道沟年内分配差异较大,不均匀系数分别为0.90、1.11,观景台沟年内径流过程较稳定,不均匀系数为0.70。最近10余年来,冰川河的年径流量呈单调上升趋势,年递增率为0.93m3/s,其中夏季径流量增幅最为明显,冬春季节气温的升高、春秋季降水量的增加以及全年水面蒸发量的显著减少可能是其径流变化的原因。森林区观景台沟径流量多年变化不显著,变差系数为0.09,年递增率为-0.004m3/s,夏季径流减少幅度最大,降水量的减少是主导因素,该沟雨季径流量的波动变化控制着年径流量多年变化。森林区对气候变化的敏感性小于冰川河。

A glacial river and three gullies of different scales in the （Eastern Slope of the forest area in Gongga Mt are selected, combined with the datas of runoff and their corresponding precipitation and temperature in recent ten years, and the comparative analysis of runoff components, annual runoff distribution, inter-annual runoff venialities in the adjacent glacial and forest areas are given using runoff separation, correlative analysis and other methods. The results indicate that： The glacial river in Hailuo Ravine is mainly supplied by glacial meltwater （50. 1% ）, roundwater（27.9 % ）, recipitation （ 18.2 % ）. The key components are glacial runoff（62. 3 % ）and rainfall runoff （22. 7 % ） from June to September, while the main components are groundwater （67.9 % ） and snowmeh water （22. 55 % ） in dry seasons, the uneven index of annual distribution is 0. 76; the gullies in forest area are mainly supplied by groundwater, while are rainfall in wet seasons. Both Huangbengliu Gully and Madao Gully have higher unevenness of annual runoff, and the indices are 0. 90,1.11 respectively. Guanjingtai Gully has a steady annual runoff process, and the uneven index is 0. 70. The annual runoff of glacial river has a monotonous rising trend in recent ten years, and the ascending rate is 0. 93 m^3/s. The increase amplitude of summer runoff is the most significantly. The rise of temperature in spring and winter, the increase of precipitation in spring and autumn, the significant decrease of evaporation in the whole year are possible reasons of runoff variation. There is no significance of inter-annual runoff variability in Guanjingtai Gully in forest area, and the variation coefficient is 0. 09, and the ascending rate is -0. 004 m^3/s. The decrease amplitude of summer runoff is the most significantly and the leading factor is the reduction of the precipitation, so the inter-annual runoff variability is controlled by the runoff fluctuation in rainy season. The sensitivity of runoff to climate change in forest area is higher than glacial river.