Characterization and quantification of within-year variation of snow-cover elevation in mountainous regions, eastern Tibet  

作　　者：Jie Gao XuDong Fu TongLiang Gong GuangQian Wang Hao Wang 

机构地区：[1]State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China [2]Tibet Bureau of Water Resources, Lhasa 850000, China [3]Hydropower and Water Resources Planning ＆ Design General Institute, Beijing 100120, China

出　　处：《Research in Cold and Arid Regions》2011年第5期400-407,共8页寒旱区科学（英文版）

基　　金：supported by the National Natural Science Foundation of China under Grant No.50221903;by the Ministry of Science and Technology of China under Grant No.2007BAC06B06

摘　　要：Fluctuating snow-covered elevation （FSCE） was conceptualized and proposed to characterize within-year variation of the border between snow-covered and snow-free area in mountainous regions. Two parameters, namely median of snow flee period （Tm） and snow free duration （AT）, were defined to quantify FSCE. A regression model of FSCE was developed for the Lhasa River Basin, Niyang River Basin, and Changdu region in eastern Tibet. Statistical analysis of the snow-products data with a spatial resolution of 25km×25km shows that： （1） Tm correlates weakly with geographical and topographic factors, having the yearly mean value of July 31; （2） △T correlates significantly with the average elevation of the snow-products cell, having the yearly mean value of nearly five months （i.e., 151 days）; （3） the region begins snow disappearance in late April and finishes snow coverage in mid November, being snow-free from late June to mid September and snow-covered from December to March in the next year. In addi- tion, snow-products with higher spatial resolution will be helpful to characterize FSCE in smaller spatial scales.Fluctuating snow-covered elevation （FSCE） was conceptualized and proposed to characterize within-year variation of the border between snow-covered and snow-free area in mountainous regions. Two parameters, namely median of snow flee period （Tm） and snow free duration （AT）, were defined to quantify FSCE. A regression model of FSCE was developed for the Lhasa River Basin, Niyang River Basin, and Changdu region in eastern Tibet. Statistical analysis of the snow-products data with a spatial resolution of 25km×25km shows that： （1） Tm correlates weakly with geographical and topographic factors, having the yearly mean value of July 31; （2） △T correlates significantly with the average elevation of the snow-products cell, having the yearly mean value of nearly five months （i.e., 151 days）; （3） the region begins snow disappearance in late April and finishes snow coverage in mid November, being snow-free from late June to mid September and snow-covered from December to March in the next year. In addi- tion, snow-products with higher spatial resolution will be helpful to characterize FSCE in smaller spatial scales.

关 键 词：fluctuating snow-covered elevation （FSCE） eastem Tibet median of snow-flee period duration of snow-flee period 

分 类 号：TP751[自动化与计算机技术—检测技术与自动化装置] Q958.575[自动化与计算机技术—控制科学与工程]