Analysis of Topographic and Snowpack Evolution in Debris Flow-Prone Areas of Xinjiang's Alpine Region
This study investigates the Yarkant River basin in Xinjiang's alpine region using a digital elevation model and cloud-free 500m snow data from MODIS.The region was classified into two zones based on debris flow hazard characteristics:a debris flow-prone zone(very high/high susceptibility)and a non-prone zone(low/very low susceptibility).The geologic conditions and snowpack evolution characteristics of each zone were analyzed.The results show:(1)The primary geological conditions in the debris flow-prone zone are elevations:4 000～5 000m,slopes:8°～20°,and shaded slopes(3.10％of the prone zone).Hazard sites are mainly concentrated in areas with elevations below 3 000 meters,slopes of 8°～20°,and semi-shaded aspects.(2)The snow cover percentage(SCP)in the very high susceptibility zone is the lowest among all zones(average SCP:10.26％)and exhibits the greatest inter-annual variability(largest standard deviation).Conversely,the high susceptibility zone generally has the highest SCP(average SCP:40.52％)with lower inter-annual variability.(3)Snow-covered days(SCD)are longer in the debris flow-prone area(110.6 days)compared to the non-prone area(86.86 days),and both the onset date of snow cover(SCOD)and the start date of snowmelt(SCMD)are earlier in the prone area(SCOD:339.46/342.70DOY;SCMD:97.59/102.46DOY).Both zones show decreasing trends in SCD and SCMD,and an increasing trend in SCOD,with the debris flow-prone area exhibiting more pronounced changes,leading to a longer SCD.This study quantitatively analyzes the topographical and snowpack characteristics of debris flow-prone areas in the Yarkant River basin,providing a foundation for the prevention and management of debris flow disasters in Xinjiang's alpine mountains;Snowpack characteristics;Topographic variables.
debris flowsnowpack evolutionalpine regionsdigital elevation modelgeological zoningspatial and temporal patterns
NETL
NSTL
万方数据
