基于高光谱植被指数的叶片净光合速率Pn反演  

Net Photosynthetic Rate Inversion Based on Hyperspectral Vegetation Indices

作　　者：王娣[1] 佃袁勇[2] 乐源[1] 黄春波[2] 

机构地区：[1]武汉大学遥感信息工程学院,湖北武汉430079 [2]华中农业大学园艺林学学院,湖北武汉430070

出　　处：《地理与地理信息科学》2016年第4期42-48,共7页Geography and Geo-Information Science

基　　金：国家863项目"作物生长信息的数字化获取与解析技术"(2013AA102401);国家自然科学基金项目"基于叶面积指数的城市绿地固碳释养与降温增湿功能反演"(31270744);国家自然科学基金项目"基于体素特征的森林冠层叶绿素反演研究"(41501365)

摘　　要：植物净光合速率是衡量植被生产力、体现植物整体长势的重要指标。该文在分析植被光谱指数VI、光合有效辐射PAR与净光合速率Pn关系的基础上,建立了基于高光谱遥感数据的净光合速率反演模型。采集武汉市4种常见植被叶片共124个样本作为研究对象,在分析比较9种不同光谱指数与SPAD相关性的基础上选择3种相关性较高的植被指数对不同的植被类型进行净光合速率反演模型建立。结果表明:实验中CIrededge、NDVI705和RVI7003种植被指数与SPAD相关性较高,R2值均在0.7以上,最高达到0.88;在建立净光合速率反演模型时,若仅考虑叶片净光合速率(Pn)与植被指数的关系,其相关性较差;而将植被光谱指数、光合有效辐射(PAR)乘积后再与净光合速率(Pn)分析时,发现其相关性显著提高;以上3种植被指数中CIrededge*PAR vs.Pn反演效果最优,但农作物与园林植物净光合速率反演最优模型存在差异。因此,利用高光谱遥感技术可以了解和掌握植物叶片的光合效应,以此评价植物固碳释氧能力以及估测农作物产量是完全可行的。In this paper,we analyzed the correlation between the 9vegetation indices of the plant and the chlorophyll SPAD values,and then select the better ones to study the correlation between them and the net photosynthetic rate respectively.The results showed that compared with the other six vegetation indices,the CIrededge,NDVI705 and RVI700have obvious advantages.They have higher correlation R2 with SPAD,the R2 value were above 0.7,the highest one reached 0.88;when only considering the relationship between the net photosynthetic rate（Pn）and spectral vegetation index（VI）,the result was not good;but when use the product PAR＊VI（the vegetation index was multiplied by the photosynthetic active radiation）instead of VI,the correlation with Pn was significantly improved.The results showed that CIrededge＊ PAR vs.Pn model has high fit results with R2 values all up to 0.6.CIrededgebehaved better than the other two vegetation indices in the Pn inversion,but different in the crop and landscape plant,the optimal model is y=3.422＊lnx-8.123（R2=0.64,RMSE=3.1825）in the crop,y=2.118＊lnx-5.250（R2=0.66,RMSE=2.238）in the landscape plant respectively,and y=0.02＊x＋2.13（R2=0.62,RMSE=2.814）when ignoring the difference between vegetation types.This method makes up the defect of the traditional research methods which are time consuming and laborious in a certain extent,it meets the need of ecological environment monitoring,and it has the potential application value in the estimation research of releasing oxygen and crop yield.

关 键 词：高光谱 净光合速率 叶绿素SPAD 红边指数CIrededge 光合有效辐射 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置] Q945.11[自动化与计算机技术—控制科学与工程]