Remote sensing classification and extraction of alpine wetlands information in summer in Dam Qu Watershed,the source of Yangtze River
As the real source of the Yangtze River,Dam Qu Watershed is covered with a large number of alpine wetlands.Due to the dispute on the determination of the source of the Yangtze River in early years and difficulties in scientific research caused by the harsh natural environment,Dam Qu Watershed has not received widespread attention.Consequently,research on wetlands in this area is limited,particularly in high-resolution wetland classification,leaving a significant gap in the literature.Based on Sentinel-2B images from August 19,2020,the information on each category of alpine wetlands in Dam Qu Watershed was extracted by using the hierarchical classification method of object-oriented features,and the horizontal and vertical distribution characteristics of wetlands were summarized in combination with the surface morphology and texture of the study area.The results show that the alpine wetlands in Dam Qu Watershed are divided into three first-level categories and nine second-level categories,with a total area of 3 364.74 km2,of which the main part is marsh wetlands,with an area of 2 908.94 km2,accounting for 86.45％of the total area of wetlands.The areas of river wetlands and lake wetlands are similar,at 269.28 km2 and 186.52 km2,respectively.In addition to alpine wetlands,there are permanent glaciers and snow in the watershed,with an area of 107.17 km2.The horizontal distribution of wetlands in the watershed is generally characterized by more wetlands in the southeast and fewer in the northwest.These wetlands are mainly concentrated in the flat beach surrounded by hills or the catchment area with low terrain and poor drainage,as well as the foot of shady slope.In the vertical direction,alpine wetlands are mainly distributed in the range of 4 650-5 100 m above sea level.As the terrain rises,wetland resources gradually decrease.Areas above 5 400 m are mainly covered by glaciers and snow,with almost no alpine wetland.This study provides a scientific basis for the effective protection and rational utilization of wetland resources in the source of the Yangtze River.
the source of the Yangtze RiverDam Qu Watershedalpine wetlandobject-oriented featureshierarchical classification
万方数据
维普
