基于SPOT-VGT NDVI的恩施自治州地表植被覆盖变化分析

Change Analysis on Vegetation Coverage of Enshi Autonomous Prefecture Based on SPOT-VGT NDVI

利用1999-2008年SPOT—VGTNDVI时间序列数据集分析了10年间恩施州植被覆盖变化，研究结果表明：恩施州植被覆盖状况在10年内有较明显的改善，NDVI年平均值从1999年的0．564增长到了2008年的0．604，99％以上的区域植被指数趋向于正向增长；东部地区植被覆盖状况优于西部地区，在全州8个县市中鹤蜂县2008年NDVI年平均值最高，利川市最低；10年间恩施州西南部的来凤县与咸丰县地表植被变化率最大，西北部的利川市与东部的巴东县和鹤峰县地表植被变化率明显落后于其他县市。区域植被监测变化表明天然林保护工程与退耕还林工程等林业工程的实施，恩施州植被覆盖状况有了较明显的提高，有效地改善了恩施州区域生态环境，区域经济社会可持续发展能力在稳步提高。

Vegetation coverage change in Enshi autonomous prefecture in Hubei province was analyzed based on SPOT-VGT NDVI data for 10 years during 1999-2008, the research results showed that the region vegetation coverage had been significantly improved with annual average NDVI （Normalized Difference Vegeta- tion Index） increasing from 0. 564 in 1999 to 0. 604 in 2008, and the total area which annual average NDVI tended to positive increase during 1999-2008 accounted for 99%. The eastern part was better than the western region, the County with the highest annual average NDVI in 2008 was Hefeng and the lowest was Lichuan.The region Vegetation coverage change indicated that the counties with the most obviously change were Laifeng and Xianfeng located in southwest of Enshi autonomous prefecture, and the slightest change counties were Lichuan located in southeast and Badong and Hefeng located in east of Enshi autonomous prefecture. Regional vegetation change showed that the regional vegetation cover have being improved distinctly with the implementation of a series of forest project such as natural forest protection project and ＂Grain for Green＂ project, regional eco-environment had been improved effectively and the capacity of regional economic and social sustainable development is improving steadily.