Impacts of topographic factors on regional snow cover characteristics
Impacts of topographic factors on regional snow cover characteristics
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DOI：
10.1016/j.wse.2020.09.002
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发表时间：
2020-09
影响因子：
4
通讯作者：
M. Saydi;Jianli Ding
中科院分区：
文献类型：
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作者：
M. Saydi;Jianli Ding
在局部范围内，积雪受到地形特性的影响，并影响到一些干旱和半干旱地区的水资源供应。本研究旨在基于中分辨率图像分光辐射计（MODIS）的每日积雪产品，通过空间和向后时间滤波器处理，量化地形效应导致的积雪空间异质性。选取中国北方天山中段的一个积雪优势区，对积雪覆盖率（SCR）和积雪日数（SCD）进行了调查。结果表明，MODIS影像对研究区积雪有低估的倾向，其误差主要表现在1 500-2 500 m高程段。积雪主要受海拔高度的影响，积雪主要集中在3800 m以上。另外，南北坡的SCR和SCD差异比东西坡的差异更显著。值得注意的是，朝北的斜坡具有SCR和SCD的最大值，而朝南的斜坡具有SCR和SCD的最小值。此外，坡度对积雪的影响因季节而异。冬季坡面积雪量随坡度的增加而减少，其他季节随坡度的增加而增加。总体而言，本研究提供了一个有用的视角，在区域积雪的变化，并提供了指导不同地形特征的雪融水的水资源管理。
At a local scale, snow cover is influenced by terrain properties, and it affects water availability across some arid and semiarid regions. This study aimed to quantify the spatial heterogeneity of snow cover due to topographic effects based on moderate-resolution image spectroradiometer (MODIS) daily snow cover products, processed with spatial and backward temporal filters. A snow-dominant region in the middle section of the northern Tianshan Mountains in China was selected, and the snow cover ratio (SCR) and the number of snow cover days (SCD) were investigated. The results suggest that MODIS images are biased toward underestimation of the snow cover in the study region, and the error is primarily manifested within the elevation band of 1 500–2 500 m. The snow cover is mainly affected by elevation, and snow mostly accumulates above 3 800 m. In addition, the differences in SCR and SCD between the south- and north-facing slopes are more significant than those between the east- and west-facing slopes. Notably, the north-facing slopes have the maximum values of SCR and SCD, whereas the south-facing slopes have the minimum values of SCR and SCD. Furthermore, the impact of slope gradients on snow cover varies across seasons. Snow cover on a sloped surface decreases with the slope gradient during winter, while it tends to increase with the slope gradient during the other seasons. Overall, this study presents a useful perspective on the variance in regional snow cover and provides guidance for the water resources management of snow meltwater with different terrain features.