摘要
南水北调中线工程是我国大规模跨流域调水工程的一部分,开展该区域植被覆盖度变化的研究与分析,对于保护该区域的生态环境及水质具有重要意义。该文以2000年和2009年两期遥感图像为本底数据,利用基于NDVI的像元二分模型对南水北调中线水源区的植被覆盖度进行了估算,并分析了该区植被覆盖度的时空变化特征。结果表明:2000年该水源区植被覆盖度的平均值为67.5%,2009年的平均值达到72%,植被覆盖度总体呈增长趋势;植被覆盖度增幅的空间特征表现为水源区中部地区高,东西部地区相对较低;在不同植被类型中,落叶针叶林的覆盖度平均值增幅最大,草地覆盖度增幅最小;位于水源区的大多数县(市)的植被覆盖度在近十年来都有不同程度的增加,其中柞水县的植被覆盖度平均值增长幅度最大,这与国家实施退耕还林、封山育林、基本农田建设等政策有关。
The middle route of the projects to divert water from the south to the north is a part of the large-scale inter-basin water transfer projects in China.It is important to carry out the study and analysis of changes of regional fractional vegetation cover for the protection of ecological environment and water quality.In this paper,based on the data of the remote sensing images obtained in 2000 and 2009,the authors estimated fractional vegetation cover of the water source area by using the method of dimidiate pixel model from normalized difference vegetation index(NDVI),and analyzed the temporal and spatial variation characteristics of the fractional vegetation cover.The main conclusions are as follows: The average fractional vegetation cover in the water source area was 67.5% in 2000,and reached 72% in 2009,with the average fractional vegetation cover being increased in the whole area.The spatial characteristics of increased fractional vegetation cover show that the increase in central region is relatively higher than that in the eastern and western regions;in different kinds of vegetation types,the deciduous conifer forest shows the largest average increase of the fractional vegetation cover,while the grassland shows the smallest increase;fractional vegetation cover has increased in different degrees in most towns of the water source area in the past 10 years,with the increase in Zhashui County being most apparent.This is attributed to the Chinese Government's policies such as quitting cultivation and returning to forest,closing hillside to facilitate afforestation and farmland construction.
出处
《国土资源遥感》
CSCD
北大核心
2012年第1期70-76,共7页
Remote Sensing for Land & Resources
基金
中国科学院战略性先导科技专项(编号:XDA05050108)
国务院南水北调项目"利用遥感技术对南水北调中线水源区生态环境变化的监测研究"共同资助
关键词
植被覆盖度
南水北调中线水源区
遥感监测
fractional vegetation cover
water source area of the middle route of projects to divert water from the south to the north
remote sensing monitoring