Monitoring the vegetation deterioration and recovery of serious disaster area in Wenchuan Earthquake based on remote sensing

The devastating Wenchuan Earthquake with a magnitude of 8.0 occurred in Sichuan Province, Southwest China, on May 12, 2008, which had seriously interfered with the ecosystem in the disaster regions, resulting in large areas of vegetation deterioration and soil erosion. This study monitored the vegetation deterioration and recovery in three serious disaster regions, which were Wenchuan Count, Yingxiu Town and Zipingpu Reservoir separately, by using NDVI-based quantitative indexes coupled with multi-temporal Landsat/TM and EO-1/ALI images and digital elevation model (DEM). The results indicated that vegetation destruction in these regions after earthquake was very serious, and the areas of destroyed vegetation in Yingxiu Town, which as the earthquake center, had accounted for 51%. The average vegetation recovery ratio in the three regions reached 75.8%, 55.4% and 41.5% on August 28, 2011, 3 years after the earthquake under natural vegetation succession, and the vegetation recovery was still ongoing from the trend of vegetation activities. Vegetation deterioration and recovery had a close relationship with the slope that vegetation was most likely to recover in the slope between 35 to 45. The study results provide very useful information for ecological reconstruction and recovery in the disaster areas.