Spatial and Temporal Variations of Vegetation Coverage in Karst Areas under the Background of Ecological Recovery:A Case Study in the Central Area of Guizhou Province

In order to reveal spatial and temporal variations of vegetation coverage in the karst areas under the driving force of ecological restoration projects such as the project of Convert Cultivated Land into Forest and Grass,the project of Afforestation and the project of comprehensive treatment of Karst Rocky Desertification.By using the MODIS image data in the years of 2000,2005and 2010to evaluate the vegetation dynamic change in the central area of Guizhou by the method of NDVI dimidiate pixel model.the results showed that from 2000to 2010,extremely high vegetation coverage sustainably grew;high vegetation coverage gradually declined;extremely low vegetation coverage,low vegetation coverage and secondary vegetation coverage showed an increasement and then were followed by a decline.Vegetation coverage seems to be better in general.Moreover,the landscape patch number of vegetation reduction,the average patch area grew and the Shannon diversity index number decreased,which reflected that the landscape fragmentation degree was gradually reduced and there was an achievement of ecological restoration projects in the study area from 2000to 2010.