摘要
基于遥感数据 M ODIS NDVI ，利用像元二分模型定量估算了三峡库区重庆段不同时期（2000－2003年，2004－2007年，2008－2011年）植被覆盖度的变化。将植被覆盖度划分为4个等级：I级（0％～40％）、II级（40％～60％）、III级（60％～80％）、IV级（80％～100％），结合景观生态学理论分析了植被覆盖景观格局随时间的动态变化。结果表明：2000－2011年，III ，IV级所占面积比例之和达到90％以上，是研究区植被覆盖景观的基质。植被覆盖变化的总体趋势为低覆盖度类型向高覆盖度类型转变，整体呈现正向演替的良性发展。近12年来，研究区内植被覆盖景观中各斑块类型在优势度、破碎度、形状、连通性等方面变化差异明显。整体植被覆盖景观格局的镶嵌程度增加，形状趋于复杂，多样性和异质性不断增强，对植被覆盖景观格局起支配作用的优势斑块类型由III级逐渐转变为IV级，各斑块类型在空间上的分布趋向均衡化，结构趋于复杂化，其中III ，IV级特征的变化对植被覆盖景观格局动态起决定性作用。三峡库区植被覆盖景观格局积极变化的主要原因极有可能是近年来由政府主导开展的生态建设和生态恢复。
Using a dimidiate pixel model ,the vegetation coverage of different periods （2000-2003 ,2004-2007 and 2008-2011） in Chongqing Section of the Three Gorges Reservoir Region was quantitatively esti‐mated based on the MODIS NDVI remote sensing data .The vegetation coverage was classified into four levels ：I （0% ~ 40% ） ,II （40% ~ 60% ） ,III （60% ~ 80% ） and IV （80% ~ 100% ） ,and the dynamic change in landscape pattern of vegetation coverage in this region from 2000 to 2011 was analyzed with the theory of landscape ecology .The results showed that levels III and IV constituted the major landscape types over the 12 years ,accounting for more than 90% of the study area .As a whole ,the variation trend of vegetation coverage was that low coverage level was transformed into high coverage level ,indicating a positive evolution succession of vegetation coverage .The dominance ,fragmentation ,shape complexity and cohesion among different vegetation coverage levels were obviously different .The landscape level index in‐dicated that patch mean area and contagion index decreased continuously ,in contrast to an increase of the landscape shape index ,Shannon＆#39;s diversity index and Shannon＆#39;s evenness index .The fragmentation and shape complexity of the landscape pattern increased ,and the landscape pattern development exhibited to‐wards a diversifying and balancing trend ,and the dominant landscape type gradually shifted from level III to level IV .The results above suggested that levels III and IV had significant effect on landscape pattern dynamic change of the w hole study area .T he anthropogenic factors such as government‐guided ecological construction and restoration measures were the main causes leading to the vegetation coverage landscape pattern change .
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2014年第12期141-147,共7页
Journal of Southwest University(Natural Science Edition)
基金
国家自然科学基金(3170404)
国家科技部国际合作专项(2011DFG32780)
国家林业公益性行业科研专项(201004039)
重庆市自然科学基金重点项目(CSTC2013JJB00004)
留学回国人员科研启动基金项目(教外司留[2010-1561])
中央高校基本科研业务费专项资金(XDJK2013A011)
关键词
植被覆盖度
景观格局
三峡库区重庆段
MODIS
NDVI
vegetation coverage
landscape pattern
Chongqing Section of the Three Gorges Reservoir Re-gion
MODIS NDVI
