Research on FBM characters of watershed vegetation feature based on NDVI

摘要

It is an important research direction that quantifies and expresses the spatial distribution complexity of vegetation cover at the time of studying the relationship between vegetation and matter migration on the watershed. In this paper, fractal dimensions of FBM for watershed vegetation cover are calculated on the basis of GIS, FBM theory and spatial distribution of NDVI. The results showed that the spatial distribution of vegetation on the watershed possesses a strong self-similarity and can be described by FBM theory. Fractal dimensions of FBM for watershed vegetation cover is ranging from 2.5 to 3. When it is getting close to 2.5 the spatial distribution of vegetation is more complicated.. There are no direct relationships between fractal dimension of FBM for watershed vegetation cover and the averaged NDVI of watershed or coefficient variation of NDVI for pixel. There exists nagtive relationships between fractal dimension of FBM for watershed vegetation cover and the numbers of different NDVI per square kilometer. Fractal dimension of FBM for watershed vegetation cover increases with an rise of watershed area and is toward quasi-steady state when watershed area reaches to a given scale. Compared with the traditional quantified parameter of vegetation cover, fractal dimension of FBM takes advantage of conquering the effect of singular value of NDVE and being used widely.