冰沟流域积雪面积比例与雪水当量关系初探

像元尺度上积雪面积比例与雪水当量的关系是将积雪遥感面积数据引入水文模型的有效手段。以冰沟流域为例,利用合成孔径雷达ENVISAT-ASAR数据反演得到积雪面积、雪水当量信息,分析了500m像元尺度上积雪面积比例与雪水当量的关系。结果表明:1在积雪面积比例未达到全覆盖饱和状态,雪水当量和积雪面积比例呈正相关关系,积雪面积比例控制着雪水当量的最大值,但由于受到地形的影响,关系不显著;2当考虑地形因子影响,即将坡度、坡向、海拔、积雪面积比例与雪水当量进行多元线性回归,回归系数的显著性水平均小于0.05,相关系数(r)达到0.841。因此,在高分辨率地形因子已知的情况下,结合遥感积雪数据,可建立良好的积雪面积比例和雪水当量之间的关系,有利于高分辨率积雪面积比例数据在寒区分布式水文模型中的应用。

Study of the Relationship between Snow Cover Fraction and Snow Water Equivalent in Binggou Watershed

The relationship between snow cover fraction and snow water equivalent at pixel scale is an effective approach of applying high resolution optical remote sensing data in hydrological models.Binggou watershed was selected as the study area in this paper this paper.Retrieved snow cover fraction (SCF) and snow water equivalent (SWE) information through the ENVISAT-ASAR data,thus resamples the SCF and SWE data in 500m resolution and analyzes the relation between SCF and SWE.The results show that:①Without the concern of topographic factors,snow cover fraction and snow water equivalent is a discrete distribution,however,snow cover fraction determines the maximum value of snow water equivalent,and the average snow water equivalent improves with the increased snow cover fraction;②When considering topographic factors,the multifactor regression analysis of snow water equivalent and snow cover fraction,slope,aspect,altitude show that the regression coefficient significance level is less than 0.05,and the correlation coefficient reaches at 0.841.Therefore,snow cover fraction can be converted into snow water equivalent according to the analysis of specific snow depletion curve,thich provides a solution to fuse the remote sensing data into cold region hydrological model.