生态恢复背景下喀斯特地区植被覆盖的时空变化——以黔中地区为例

为了揭示退耕还林(草)、封山育林和石漠化综合治理等生态恢复工程驱动下喀斯特地区的植被覆盖度的时空变化情况,以黔中为研究区,利用2000年、2005年和2010年三期的MODIS影像数据,通过NDVI像元二分模型法,对研究区植被覆盖进行了动态变化评估。结果表明:2000年到2010年,极高植被覆盖度面积持续增长,高植被覆盖度面积持续减少,极低植被覆盖度、低植被覆盖度和中等植被覆盖度面积先增后减,植被覆盖总体呈现转好趋势;此外,植被覆盖景观斑块数减小,平均斑块面积增大,香农多样性指数减小,表明这一时期内植被覆盖景观的破碎化程度逐渐降低,生态恢复工程取得良好实效。

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, 2005 and 2010 to evaluate the vegetation dynamic change in the central area of Guizhou by the method of NDVI dimidiate pixel model. the results showed that from 2000 to 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 2000 to 2010.