A study of natural recovery of vegetation in Wenchuan Earthquake affected zone via remotesensing

Based on multi-temporal remote sensing data and spatial analysis of GIS, this paper analyzes the characteristics of the ecological destruction and recovery in the seriously damaged areas of Wenchuan Earthquake. By employing the TM, MODIS NDVI multi-temporal data, it analyzes the changes in vegetation and using the Vegetation recovery rate to evaluate the recovery characteristics. The result shows that the forest and grassland areas declined significantly. The multi-temporal NDVI data also shows the fluctuation before and after the earthquake. The average VRR was 37.4% until September 2009. The areas located on the slope base which had been corroded by flowing water and the steep mountain ridges are in undesirable situation. There are drought resistance shrub and grass growth beside the roads and dried vallies, and now they are spreading to the collapsed and landslide areas. The soil, climatic, and water-thermal-fertility conditions are the important factors for vegetation recovery.