Spatial-Temporal patterns of vagetation damage and recovery after the wenchuan earthquake

Spatial heterogeneity is a universal phenomenon that exits in ecological systems. In addition, it is one structural feature of ecological systems. Hence, quantification of spatial heterogeneity can examine structure of ecological systems. The Wenchuan earthquake triggered cascading disasters of landslides and debris flows that caused severe vegetation damage. Besides detecting the change, the magnitude of such change is also need to be examined. Remote sensing and geographic information system techniques were used to produce landscape maps before and after the earthquake and analyze the spatial-temporal change of vegetation pattern. Landscape metrics were selected to quantify spatial heterogeneity in categorical map in both class-level and landscape-level. Results reveal that the Wenchuan earthquake increased the heterogeneity seriously in the study area; it is obviously embodied in forests, which got the most fragmentation among all the landscape component types.