2001年至2010年昆马力克河流域积雪时空变化特性分析

Spatial and Temporal Characteristics of Snow Cover in the Kunmalike River Basin

为对水资源重要组成部分和极端水文事件频发诱因之一的积雪融水有较好的认识，本文基于2001年-2010年昆马力克河流域8d MODIS积雪合成数据，从整个区域、不同坡度、不同坡向和不同海拔高度对其积雪时空变化规律进行研究。结果表明：昆马力克河流域最大积雪覆盖面积出现在1月，最小积雪覆盖面积出现在8月，冬季积雪所占比例最大；从坡向看，四季中最大积雪覆盖率出现在冬季坡向为22．5-67．5°的东北坡，为77．9％，最小积雪覆盖率出现在夏季坡向为157．5—202．5°的南坡，为28．3％；从坡度看，四季中最大积雪覆盖率出现在坡度〉60°的区域，最大值出现在春季，为82．2％，最小积雪覆盖出现在坡度为0～10°区域，以夏季最小，为29．9％；从高程带看，最小积雪覆盖率出现在海拔高度小于2000m的区域，最大积雪覆盖率出现在海拔高度大于5000m的区域，在多年平均情况下，年平均积雪覆盖率随着海拔高度的增加呈现“慢-快-慢”的增大趋势。

Snow cover plays an important role in alpine mountain rivers. Because of a low population density, expensive access, and limited human activity, alpine regions have a sparse and extremely unevenly distributed hydrometeorological network. The investigation of snowmelt hydrological processes, especially runoff generation, are now highly important and urgent. We used MODIS 8d snow cover data from 2001 to 2010 to analyze spatial and temporal variation in snow cover for the Kunmalike River basin. We looked at the entire territory, slope, aspect and different altitudes. We found that maximum snow cover is in January and minimum snow cover is in August. The snow coverage rate in January is 72.4% and in August is 30.2%. Winter snow cover occupied the highest proportion （ratio is 32.1%）, and spring, fall and summer followed with ratios of 26.7%, 26.3% and 14.9%, respectively. The maximum snow cover rate occurred in winter and over the northeast slope where the aspect is 22.5-67.5°, the proportion is 77.9%. Minimum snow cover occurred in summer and over the southern slope where the aspect is 157.5-202.5°; the proportion is 28.3%. While there are some differences in snow cover, the maximum snow cover rate occurred in areas with a slope 〉60° and the maximum value occurred in spring; the proportion is 82.2%. Minimum snow cover occurred on slopes from 0-10°, and the minimum value was in summer; the proportion is 29.9%. Minimum snow cover occurred in areas less than 2000 m a.s.1, and maximum snow cover occurred 5000 m a.s.1.