江苏沿海地区NDVI的演变特征及其对区域气候变化的响应

以江苏沿海地区为研究对象,利用1998—2008年从SPOT VEGETATION中提取的归一化植被指数(NDVI)资料,分析江苏沿海地区植被覆盖的时空变化规律。结果表明:(1)江苏沿海地区的NDVI有明显的季节变化,春季3、4月份及夏季7、8月份NDVI指数上升明显;近10年来,江苏沿海地区植被覆盖率呈增加趋势,植被状况有所改善。(2)1999年江苏沿海地区NDVI具有明显的区域差异,其表现为盐城较高、连云港次之、南通较低;到2007年连云港、南通地区NDVI明显增加,盐城地区总体增加,但区域差异较大,部分地区还出现了明显的下降趋势。(3)江苏沿海地区气候(气温、降水)因素对NDVI影响作用明显,二者均对NDVI有显著的正相关性,其中气温是主导因素。

The spatio-temporal evolution characteristics and response of regional climate change of NDVI at Jiangsu coastal areas

Based on the research area of Jiangsu coastal areas,taking advantages of NDVI information which extracted from SPOT VEGETATION from 1998 to 2008,we explored the tempo-spatial changes of vegetation coverage over Jiangsu coastal areas.The results showed that:(1) There are significant seasonal changes of the NDVI index at Jiangsu coastal areas.NDVI index rise evidently at March and April in spring,July and August in summer;the proportion of vegetation-coverage increased within the latest 10 years of Jiangsu coastal areas and the vegetation conditions are improved at the same time.(2) The NDVI varies distinctly on areas among Jiangsu coastal areas in the year of 1999: that is Yancheng>Lianyungang>Nantong.However,till 2007,the NDVI indexes of Lianyungang and Nantong areas continuously increased.The NDVI indexes within Yancheng area varies,the overall index increased during 1999 to 2007,however,some parts showed decline.(3) Climate factors(temperature,precipitation) had remarkable effects on NDVI at Jiangsu coastal areas.Both temperature and precipitation had positive effect on NDVI while temperature is the dominant factors.