基于Landsat时间序列的香格里拉市土地覆盖变化检测

Land Cover Change Detection in Shangri-La Based on Landsat Time Series

  • 摘要: 基于Google Earth Engine平台,使用Landsat Level遥感影像,利用归一化燃烧指数作为LandTrendr时间分割算法的光谱数值,对香格里拉市进行土地覆盖变化检测。结果表明:1986—2016年,林地、未利用地、永久性冰川雪地面积持续减少,草地、水体和建设用地面积持续增加;林地为香格里拉最主要的土地覆盖类型,总占比超过80%。香格里拉土地覆盖的变化动态度总体较低,土地覆盖变化过程较为平缓;大部分林地未发生变化,在31 a内以中度干扰和轻微恢复为主。但香格里拉林地总面积多年来持续减少,按干扰和恢复的持续时间来看,1986—2016年林地发生变化的主要类型为持续1~5 a的干扰和持续21~31 a的恢复。自然灾害与人为采伐的消耗速度远大于林分的自然增长速度,如果不健全林地保护的措施,林地资源将日益稀少。

     

    Abstract: Landsat remote sensing images are used in this study based on the Google Earth Engine platform. The Normalized Burn Ratio index is used as the spectral value of the LandTrendr time division algorithm to carry out land cover change detection in Shangri-La. The results show that: From 1986 to 2016, the area of forest, unused land, permanent glaciers, and snowfields are decreasing continuously. The area of grassland, water bodies and construction land are increasing. Forest is the most important land cover type in Shangri-La, accounting for more than 80% of the total. Shangri-La's land cover change dynamics are generally low, and the land cover change process is relatively stable. Most of the forest land in Shangri-La has not changed, with moderate disturbances and slight restorations in 31 years. The total area of forest land in Shangri-La is decreasing over the years. In terms of the duration of disturbance and restoration, the main types of forest land changes from 1986 to 2016 are disturbances lasting 1–5 years and restoration lasting 21–31 years. Natural disasters and man-made logging consume forest land at a much faster rate than the natural growth rate of forest stands. If forest land protection measures are not perfected, forest land resources will become increasingly scarce.

     

/

返回文章
返回