林西县近30年植被覆盖率时空变化分析

Analysis on Temporal and Spatial Variation of Vegetation Coverage in Linxi County in Recent 30 Years

摘要: 林西县是内蒙古东部的重要组成部分，其植被的动态变化对林西县以及内蒙古东部地区的生态可持续发展有重要意义。本文基于Landsat-5与Landsat-8影像，通过Envi，Arcgis等软件处理林西县1990~2020年数据，提取NDVI和根据植被覆盖指数并进行分级，分析林西县近30年植被覆盖率时空变化特征和探讨其影响因素。结果显示：(1) 总体上看，林西县30内植被覆盖度剧烈减少，随时间变化幅度较大，在1990~2000年期间植被覆盖下降极其显著，仍有下降的趋势；2000~2010呈轻微上升，植被状况有所改善；2010~2020又轻微下降，且趋势明显。(2) 空间上林西县植被覆盖分布不均，北多南少，植被覆盖北部变化较大，南部变化较小。(3) 林西县植被覆盖的变化在空间分布特征上受到地形与气候的影响，年际数量变化上，受到经济发展、人口和政策的影响。

Abstract: Linxi County is an important part of eastern Inner Mongolia, and the dynamic change of its vegetation is of great significance to the ecological sustainable development of Linxi County and the eastern part of Inner Mongolia. In this paper, based on Landsat-5 and Landsat-8 images, the data of Linxi County from 1990 to 2020 are processed by Envi, Arcgis and other software, NDVI is extracted and classified according to vegetation cover index, the temporal and spatial variation characteristics of vegetation coverage in Linxi County in recent 30 years are analyzed and its influencing factors are discussed. The results showed that: (1) on the whole, the vegetation coverage decreased sharply in Linxi County, and changed greatly with time. From 1990 to 2000, the vegetation cover decreased extremely significantly, and there was still a downward trend; from 2000 to 2010, the vegetation increased slightly, and the vegetation condition decreased slightly from 2010 to 2000, and the trend was obvious. (2) The spatial distribution of vegetation cover in Linxi County is uneven, which is more in the north and less in the south. The vegetation cover changes greatly in the north and little in the south. (3) The change of vegetation cover in Linxi County is affected by topography and climate in spatial distribution characteristics, and by economic development, population and policy in interannual quantity change.