摘要
当曲作为长江正源,其流域内覆盖着成片的高寒湿地。由于早年在江源定位上存在的争议及自然环境恶劣科考困难,当曲流域未能受到广泛关注,湿地研究工作薄弱,在高分辨率湿地分类研究上仍处于空白。基于2020年8月19日的Sentinel-2B影像(10 m分辨率多光谱数据),采用面向对象特征的分层分类法,对当曲流域各类别高寒湿地的信息进行提取,结合研究区地表形态、质地等对湿地的水平及垂直分布规律进行总结。结果表明:1)当曲流域高寒湿地共分为3个一级类和9个二级类,总面积为3 364.74 km^(2)。其中主体部分为沼泽湿地,分布面积达2 908.94 km^(2),占湿地总面积的86.45%,河流湿地和湖泊湿地面积相近,分别为269.28 km^(2)和186.52 km^(2)。除高寒湿地外,流域内覆盖有永久冰川积雪,分布面积为107.17 km^(2)。2)当曲流域内湿地在水平分布上总体呈现东南多西北少的特点,主要集中于丘陵环绕的平滩或地势低缓、排水不畅的汇流地带,以及阴坡山脚地区。3)高寒湿地在垂直方向上的分布以海拔4 650~5 100 m为主,随着地势升高湿地资源逐渐减少,海拔5 400 m以上为冰川积雪集中覆盖区,几乎无高寒湿地分布。
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 3364.74 km^(2),of which the main part is marsh wetlands,with an area of 2908.94 km^(2),accounting for 86.45%of the total area of wetlands.The areas of river wetlands and lake wetlands are similar,at 269.28 km^(2) and 186.52 km^(2),respectively.In addition to alpine wetlands,there are permanent glaciers and snow in the watershed,with an area of 107.17 km^(2).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 4650-5100 m above sea level.As the terrain rises,wetland resources gradually decrease.Areas above 5400 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.
作者
谢婉蓉
刘少创
吴运佳
张烁
XIE Wanrong;LIU Shaochuang;WU Yunjia;ZHANG Shuo(CAS Key Laboratory of Digital Earth Science,Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100094,China;International Research Center of Big Data for Sustainable Development Goals,Beijing 100094,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《中国科学院大学学报（中英文）》
CAS
CSCD
北大核心
2024年第5期625-635,共11页
Journal of University of Chinese Academy of Sciences
基金
可持续发展大数据国际研究中心创新研究计划(CBAS2022IRP03)资助。
关键词
长江正源
当曲流域
高寒湿地
面向对象特征
分层分类
the source of the Yangtze River
Dam Qu Watershed
alpine wetland
object-oriented features
hierarchical classification
