Analysis of Fractional Vegetation Coverage and its Dynamic Change in the Yalong River Basin based on Dimidiate Pixel Model

Abstract

Fractional vegetation coverage (FVC) and its spatio-temporal variations are critical indicators of regional ecological changes, which are of great significance to study the laws of surface variation and analyze regional ecosystem. Under the development of RS and GIS technology, this analysis employs Landsat satellite images in 1994, 2008, 2013 and 2016 to estimate FVC in Yalong River Basin based on the Dimidiate Pixel Model. With consideration of the vegetation coverage condition and land surface law in the study area, the research further analyzes the Spatio-temporal variations as well as the influencing factors of FVC in terms of topography and land use types respectively. The results show that since 1994, FVC in Yalong River Basin has experienced a downward trend yet displaying an uptick from 2013. Moreover, different land use types indicate the versatility of land covers in Yalong River Basin, with grassland and forest performing probably the most important factors that can induce changes to the stability of FVC in whole basin. Overall, the research reflects the impact of human activities on vegetation in Yalong River Basin, and provides available data and theoretical basis for ecological assessment, ecological restoration and environmental protection.