定西市安定区植被覆盖动态监测分析

Dynamic Observation and Measurement of Vegetation Coverage in Anding Region of Dingxi City

植被覆盖度是衡量地表植被覆盖的一个重要指标,在水土流失、生态环境等领域作为重要参数输入。利用定西市安定区的1993、2005和2009年3个时期TM遥感影像,对遥感影像进行了归一化植被指数的提取。并根据像元二分模型原理求得研究区域的植被覆盖度,对该区的植被覆盖的变化情况进行遥感监测和定量分析。结果表明:由于定西安定区从2000年开始的退耕还林工程长久机制,该区的植被覆盖度由1993年的24.96%增加为2009年的55.19%,植被增加的总面积为1 099.73 km2,为该地区的水土流失治理提供了可靠的依据。

Vegetation fraction is a very important index to measure the vegetation coverage on land surface and can also be used as one of the important input parameters in such fields as soil erosion,ecological environment and so on.This paper collected the normalized different vegetation index by using the remote sensing images of TM in 1993,2005 and 2009 in Anding district of Dingxi city.According to the dimidiate pixel model,the vegetation fraction of the researched district was calculated,which has laid a foundation for remote sensing observation and quantitative analysis of vegetation coverage changes in this district.The results showed that due to the long-term mechanism for returning farmland to forest project since 2000,vegetation fraction increased from 24.96% in 1993 to 55.19% in 2009 and the total increased area of vegetation coverage was 1 099.73 km2,which directly provide a reliable basis for the management of soil erosion in this region.