基于线性光谱混合模型的荒漠草地覆盖度估测  

Assessing vegetation coverage of desert grassland based on linear spectral mixture model

作　　者：杨峰[1] 李建龙[2] 杨文钰[1] 钱育蓉[3] 杨齐[4] 杜自强[5] 

机构地区：[1]四川农业大学农学院农业部西南作物生理生态与耕作重点实验室,成都611130 [2]南京大学生命科学学院,南京210093 [3]新疆大学软件学院,乌鲁木齐830046 [4]中国环境监测总站,北京100012 [5]甘肃农业大学资源与环境学院,兰州730030

出　　处：《农业工程学报》2012年第7期243-247,F0003,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点基础研究发展计划项目(973项目)(2010CB950702);国家高技术(863计划)专题资助项目(2007AA10Z231);四川省博士后基金资助项目(04310624).

摘　　要：为了解决草地混合像元对草地植被覆盖度监测的影响,该研究以Landsat TM为数据源,探讨线性光谱混合模型进行混合像元分解的关键问题,分析混合光谱模型获得的不同组分分量与植被覆盖度之间的关系,以期建立适合天山北坡荒漠草地覆盖度监测模型。结果表明:通过光谱混合模型获得植被、沙丘以及盐碱化土壤3个基本组分,其中植被组分与覆盖度拟合效果较好(R2=0.62),与植被指数法估测草地覆盖度相比,决定系数R2均高于比值植被指数、归一化植被指数、土壤调节植被指数及修正土壤调整植被指数MSAVI。通过对所获模型精度检验,均方根误差RMSE为1.28,结果较为理想。因此,利用线性光谱混合模型解析混合像元估测天山北坡荒漠草地覆盖度具有可行性。Remote sensing offers a scientific,accurate,rapid technique for predicting plant coverage,but a pixel in remote sensing image includes more information,which will affect grassland classification accuracy and the quantitative development of remote sensing techniques.In this study,Landsat Thematic Mapper（TM）data was used to discuss the key problem of mixed pixel decomposition by using spectral mixture analysis in grassland of the Northern Tianshan Mountains.Four vegetation indexes and fractions derived from spectral mixture analysis,i.e.,green vegetation,dune,and saline alkali soil,were calculated and compared with field grassland measures.The results showed that green vegetation had higher correlations with the grass coverage than dune and saline alkali soil.In addition,green vegetation also had higher correlation（R2=0.62）than the ratio vegetation index（RVI）,the normalized difference vegetation index（NDVI）,the soil-Adjusted vegetation index（SAVI）and the modified soil-adjusted vegetation index（MSAVI）.The results imply that it is feasible for assessing desert grassland coverage in the Northern Tianshan Mountains by using mixture pixel decomposition based on linear spectral mixture model.

关 键 词：模型 遥感 监测 荒漠草地 植被覆盖度 天山北坡 

分 类 号：P237[天文地球—摄影测量与遥感]