基于遥感的近20年黄河乌兰布和沙漠段生态环境状况变化分析

Analysis of eco-environmental changes in Ulan Buh Desert section of Yellow River in the nearly 20 years based on remote sensing

本文通过遥感技术,从土地利用/覆盖、植被覆盖和生态功能三个方面对黄河乌兰布和沙漠段2000-2020年间的生态环境状况变化趋势进行分析。结果表明(:1)土地利用与覆盖类型中林地、水域湿地、建设用地、耕地面积呈增加趋势,未利用地(沙地)和草地(灌丛草地)面积呈减少趋势。(2)植被覆盖度较低,植被覆盖指数均值为15,绝大部分为植被稀疏荒漠地。近20年植被覆盖度整体上呈上升趋势,局部呈明显好转或严重退化。(3)防风固沙生态功能状况一般,生态功能脆弱,生态类型结构单一。近20年防风固沙生态功能状况总体稳定,虽略有好转趋势,变化幅度总体属于“无明显变化”。总体上,近20年由于人工“变绿”面积增加明显,黄河乌兰布和沙漠段生态环境状况整体呈好转趋势,但生态环境质量整体仍脆弱,局部生态问题依然存在。

Based b on the remote sensing technology,this paper analyzes the changing trend of eco-environment condition from 2000 to 2020 in Ulan Buh Desert section of the Yellow River from three aspects:land utilization\cover,vegetation cover and ecological function.The Remote sensing datas suggest that:(1)The area of forest land,water wetland,construction land and cultivated land increased,while the area of unused land(sandy land)and grassland(shrub grassland)decreased.(2)The vegetation coverage is low,with an average vegetation coverage index of 15,and most of them are desert lands with sparse vegetation.In the past 20 years,the overall vegetation coverage showed an upward trend with obvious improvement or serious degeneration in some parts.(3)The ecological function of windbreak and sand fixation was in general,the ecological function was fragile,and the ecological type structure was unitary.In the past 20 years,the ecological function of wind-break and sand-fixation has been stable in general,with a slight increasing trend.As a whole,the ecological environment of Ulan Buh Desert section of the Yellow River shows an improvement trend,but the quality of the ecological environment is still fragile,and the local ecological problems still exist.