关键词: 遥感, 归一化植被指数, 植被覆盖度

Abstract:

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 entironment and so on. This paper collected normalized difference 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 research 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 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 increasing area of vegetation coverage is 1099.73km², which directly provide a reliable basis for the management of soil erosion in this region.

Key words: remote sensing, Normalized Difference Vegetation Index, Vegetation fraction