利用多时相遥感影像分析密云县植被动态变化

Vegetation Dynamic Changes of Miyun County with Multi-Temporal Remote Sensing Image

利用多时相遥感影像对密云县植被动态变化发展过程进行分析,为当地气候变化和水土保持提供科学依据。研究中以3幅TM/ETM、密云县大比例尺地形图为基础。应用相关的遥感软件对3幅影像进行归一化植被指数(NDVI)及像元植被盖度的提取,结合假彩色合成原理,将提取后的NDVI影像及植被盖度影像分别进行假彩色(RGB)合成,将密云县植被的变化分为8种类别。密云县植被稳定的区域占18.26%,面积为40 902.21 hm2,其中高植被覆盖区域占12.25%,面积为27 439.65;植被不稳定的区域占81.74%,面积为183 150.54 hm2;水域面积减少44.44%,减少面积为9 947.942 4 hm2;在这17 a中,密云县地表植被没有遭到严重的破坏,但一些区域植被盖度发生了明显的变化,水域面积明显减少。

We used multi-temporal remote sensing images to analyze the vegetation dynamic change in Miyun County to provide scientific basis for the local climate,soil and water conservation. Based on three TM / ETM images and large-scale topographic map of Miyun County,we extracted NDVI and vegetation cover pixels of the imagines. Then,combining with the false color composite principle,we used false color（ RGB） synthesis for the normalized differential vegetation index（ NDVI） and vegetation cover imagines to divide the vegetation into eight categories. The stable vegetation of Miyun County accounts for 18. 26%,40 902. 21 hm2,and the high vegetation coverage area accounts for 12. 25%,27 439. 65 hm2. Unstable vegetation area accounts for 81. 74%,183 150. 54 hm2. The water area reduces by 4. 44%,9 947. 942 4 hm2. During 17 years,the vegetation in Miyun County was not seriously damaged,but some regional vegetation coverage changed seriously and the water area reduced significantly.