基于植被降水利用效率和NDVI的黄河上游地区生态退化研究  

Analysis of ecosystem degradation and recovery using precipitation use efficiency and NDVI in the headwater catchment of the Yellow River basin

作　　者：杜加强[1,2] 舒俭民[1,2] 张林波[1,2] 

机构地区：[1]中国环境科学研究院,北京100012 [2]国家环境保护区域生态过程与功能评估重点实验室,北京100012

出　　处：《生态学报》2012年第11期3404-3413,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(41001055);中国环境科学研究院中央级公益性科研院所基本科研业务专项资助项目(2009KYYW10)

摘　　要：提出了一种植被降水利用效率和NDVI变化趋势分析相结合识别生态退化、生态恢复区域的方法。利用黄河上游地区1982—2006年的AVHRR NDVI数据及同期16个气象站的降水量数据为基础数据源,计算每个像元的降水利用效率及其变化趋势,结合NDVI变化辨识生态退化和生态恢复的区域范围。结果表明,研究区域80%处于生态恢复阶段,恢复现象较为明显的区域主要位于东南部;生态退化显著的区域主要集中在玛多县县城,扎陵湖、鄂陵湖附近和龙羊峡库区周边。该结果与黄河上游地区草地退化的现状基本吻合,表明该方法可靠性较强,可以作为评估区域生态退化或生态恢复的方法。植被降水利用效率与NDVI变化趋势相结合的方法可以避免仅使用降水利用效率可能产生的误判。研究可为黄河上游地区开展生态恢复工程,合理规划和调整生态建设布局提供科学依据。The accurate identification of areas of ecosystem degradation and an objective evaluation of the effects of ecological restoration projects is necessary for ecological management and planning at the landscape scale. Ecological degradation and ecological restoration are dynamic equilibrium processes, while degradation must be considered relative to the pristine state of the ecosystem, and need to be analyzed from a time series perspective. Satellite remote sensing is widely used in ecological monitoring and assessment, as it provides extensive coverage, good spatial and temporal continuity and a long time-series dataset. This paper proposes a method for the identification of areas of ecosystem degradation and ecosystem recovery using long time-series satellite remote sensing and precipitation data, which are integrated into trend analyses of the precipitation use efficiency （PUE） and a normalized difference vegetation index （NDVI）. The PUE is calculated as the ratio of cumulative NDVI to precipitation. Significantly reduced PUE and NDVI values indicate that ecological degradation is occurring, while increasing PUE and NDVI values indicate ecological recovery. This method was applied to the headwater catchment of the Yellow River basin in China using Advanced Very High Resolution Radiometer NDVI data from 1982 to 2006 and meteorological data from the same time period. The annual PUE value was calculated using the cumulative NDVI and precipitation in the growing season for each pixel. A comparative analysis of the trends in PUE and NDVI was undertaken to detect areas of ecosystem degradation and restoration. The results show that： （i） The average PUE and NDVI values across the region increased slightly, and the area undergoing ecosystem rehabilitation during 1982-2006 comprised more than 80% of the study area. （ii） The degraded area, with significantly negative trends in the PUE and NDVI values, mainly occurred in the region surrounding Maduo County, Zaling and Eling lakes and Longyangxia Reservoir

关 键 词：降水利用效率 归一化植被指数(NDVI) 生态退化 生态恢复 识别 黄河上游地区 

分 类 号：X171[环境科学与工程—环境科学]