基于ETM和图像融合的优势植被冠层叶面积指数和消光系数的遥感反演  

Retrieving Leaf Area Index and Extinction Coefficient of Dominated Vegetation Canopy Cover in Meijiang Watershed of China Using Image-fusion and Landsat ETM Data

作　　者：赖格英[1,2] 曾祥贵[1] 刘影[1,2] 张玲玲[1] 易发钊[1] 潘瑞鑫[1] 盛盈盈[1] 

机构地区：[1]江西师范大学地理与环境学院,江西南昌330022 [2]鄱阳湖湿地与流域研究教育部重点实验室,江西南昌330022

出　　处：《遥感技术与应用》2013年第4期697-706,共10页Remote Sensing Technology and Application

基　　金：国家自然科学基金面上项目"基于多植物生长模式的SWAT农林非点源污染模拟研究--以鄱阳湖流域为例"(40971266)和"基于SWAT的鄱阳湖流域岩溶地区非点源污染模拟研究"(41171393)资助

摘　　要：叶面积指数和消光系数是表征植被群体冠层结构及光能利用的地球表层下垫面参量,国内外对叶面积指数的遥感反演有较多的研究与应用,但对消光系数的遥感反演尚不多见。我国南方少见单一大面积的均匀植被分布。为更好地匹配叶面积指数和光合有效辐射(用于估算消光系数)的实测数据,反映植被混交和疏密不均的状态,以Landsat ETM作为遥感信息源,通过HSV、Brovey和Gram-Schmidt(GS)3种图像融合方法的比较,选取效果最佳的图像融合方法,将ETM融合成空间分辨率为15m的多光谱数据。以鄱阳湖源头梅江流域为研究区,在实测优势植被叶面积指数和光合有效辐射的基础上,利用植被指数法经验公式法反演流域的叶面积指数,并根据Beer-Lambert定律,建立了流域优势植被冠层消光系数的反演模型。在此基础上,反演了流域植被冠层叶面积指数和消光系数的空间分布,为SWAT植物生长模式的修正提供输入数据基础。Leaf Area Index （LAI） and Extinction Coefficient （EC） of vegetation canopy are parameters that represent vegetation canopy structure and the earth underlying surface of light energy utilization. There are lots of research and application about the retrieving of LAI at home and abroad,however,the study about the retrieving of EC is rare. The southern of china is located in the humid subtropical region with abundant rainfall,mixed vegetation and different density. In order to better match the measured data of LAI and Pho tosynthetic Available Radiation （PAR）, and better reflect the condition of mixed vegetation and different density,This paper used the Landsat ETM image as the remote sensing data,and compared the image-fu sion methods of H SV,Brovey and Gram-Schmidt（GS）to choose the most suitable image-fusion methods to fuse the ETM image into multi-spectral data with 15 m spatial resolution, This paper selected the Meijiang watershed which is the headstream of Poyang Lake as the study area, based on the measured data of LAI and PAR of dominant vegetation, used the empirical formula method of vegetation index to retrieve the LAI and based on the Beer-Lambert law,and establish the retrieving models of EC of dominant vegetation cano py in the watershed using four vegetation indices, namely NDVI, SAVI, RVI and TSAVI. The results show that the NDVI was the most robust index with an R2 value of 0.81 for the estimating of LAI,but with an R2 value of 0.68 for the estimating of EC. Moreover, the spatial distribution of the LAI and EC was re- trieved too, which can provide important input data for the SWAT model.

关 键 词：叶面积指数 消光系数 流域优势植被 图像融合 遥感反演 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]