2000-2013年江苏省不同植被类型NDVI时空变化特征

基于2000—2013年美国国家航空航天局（NASA）发布MODIS NDVI数据产品，运用最大值合成法、趋势分析法和稳定性分析法，对江苏省近14年来不同植被类型时空变化特征进行了分析。结果表明:（1）江苏省整体植被覆盖呈下降趋势，下降速率为0.000 8/a。水田、草地呈下降趋势，水田下降趋势明显，下降速率为0.002 1/a，旱地和林地呈上升趋势，旱地上升趋势较大，为0.001 5/a；（2）近14年江苏省植被退化面积占总面积的32.21%，主要集中在城市中心区和沿江沿海环湖地区。水田退化面积呈由南往北，由东往西逐渐递增的空间分布特征，旱地退化面积主要分布在苏北地区；（3）近14年江苏省植被表现出较好的稳定性，变异系数小于10%的面积占总面积的86.97%，林地、水田和旱地稳定性较好，草地稳定性最差；（4）近14年江苏省植被NDVI、植被变化趋势与植被稳定性在空间上表现出较好的耦合性，植被NDVI高、稳定性高的地区植被以轻微改善和中度改善为主，植被覆盖度低、稳定性较差地区以轻度退化和中度退化为主。

Spatiotemporal Changes of Different Vegetation Coverage in Jiangsu Province in the Period from 2000 to 2013

Based on the data products of MODIS NDVI, published by NASA, we has analyzed the spatiotemporal changes of different vegetation coverage in Jiangsu Province in the period from 2000 to 2013. The used methods include maximum value synthesis, trend analysis and variation coefficient. The results show that: (1) vegetation coverage in Jiangsu Province decreased with an average rate of 0.000 8 every year, paddy field and grassland decreased too, paddy field decreased obviously with the average rate of 0.002 1 every year, meantime, dry land and forestland were increasing, and dry land increased more quickly with the average rate of 0.001 5 per year; (2) in the past 14 years, 32.21% of vegetation coverage degraded, the areas involved mainly locate in the center of city, around the lake and along the coastal areas, the spatial distribution characteristic of paddy field degradation illustrates the trend that the degradation aggravated gradually from the south to the north or from the east to the west, degraded region of dry land mainly distributes in the north area of Jiangsu; (3) at the same time interval, the area where the NDVI shows lower variation coefficient, namely less than 10%, accounts for 86.97% of the total vegetation area, is mainly located in forestland, paddy field and dry land, except the grassland; (4) since 2000, vegetation coverage, vegetation variation trend and variation coefficient showed the good coupling character both spatially and temporally. The area with higher NDVI and lower variation coefficient experienced mild and moderate improvement, while the area with lower NVDI and higher variation coefficient was characterized as slight and moderate degradation.