基于遥感技术的高寒草地覆盖度变化

Vegetation coverage changes of alpine grassland based on remote sensing technology

本研究在像元二分法模型的基础上,利用改进归一化植被指数的植被覆盖度定量模型,采用MODIS卫星8天合成地表反射率数据产品(MOD09A1),结合3S技术(GIS、RS、GPS)空间分析功能,以甘南州高寒草地为对象,分5个等级分别计算得到了甘南2000、2004和2008年的草地植被覆盖度,分析了甘南2000-2008年植被覆盖度变化的大致演变过程和趋势。结果表明,从2000-2008年,甘南植被覆盖度质量总体呈下降趋势,一级盖度植被退化比较严重,草地植被的演变情况主要由优等植被覆盖(一、二级)向低等植被覆盖(四、五级)演变。研究结果揭示了甘南州草地退化状况的动态趋势及严重程度,为相关政府和研究部门的草地管理决策提供了有效参考依据。

Based on the dimidiate pixel model and 3S technology（GIS,RS,GPS）,an improved vegetation coverage simulated model was built by using NDVI vegetation index.The MOD09A1 of MODIS data was used to estimate the cover of alpine grassland in the Gannan region by 5 levels in 2000,2004 and 2008.This study showed that the cover of alpine grassland in the Gannan region generally reduced from 2000 to 2008.The degradation of the first level vegetation is serious,and the main change of grassland vegetation cover indicated the better grassland with the first and second level cover turned into worse grassland with the fourth and fifth level cover.As a whole,this study showed that grassland in the Gannan region was in the status of degradation,which would provide valuable and effective advices for government for decision making.