小麦叶面积指数与冠层反射光谱的定量关系  

Quantitative relationships between leaf area index and canopy reflectance spectra of wheat.

作　　者：李映雪[1] 朱艳[1] 戴廷波[1] 田永超[1] 曹卫星[1] 

机构地区：[1]南京农业大学江苏省信息农业高技术研究重点实验室农业部作物生长调控重点开放实验室,南京210095

出　　处：《应用生态学报》2006年第8期1443-1447,共5页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(30400278);江苏省自然科学基金项目(BK2003079;BK2005212);高校博士点基金资助项目(20030307017).

摘　　要：在分析不同氮素水平下小麦叶面积指数（I棚）和冠层光谱反射率随生育期变化模式的基础上，确立了LAI与冠层光谱反射率及光谱参数的相关关系，提出了小麦LAI的敏感光谱参数及预测方程．结果表明，小麦LAI和近红外短波段（760—1220nm）反射率都随施氮量的增加呈上升趋势，可见光波段反射率则相反；从拔节期到成熟期，LAI和近红外短波段反射率均表现为先上升后下降的趋势，而可见光波段（460—710nm）反射率随生育期的推进先降低后升高，以孕穗期反射率最低，近红外长波段区域（1480-1650nm）反射率的变化与可见光部分相同．LAI与可见光波段反射率呈负相关，与近红外短波段反射率呈极显著正相关，其中以810nm相关性最好．可以选择RVI（810，510）和DVI（810，560）作为反演小麦LAI的光谱参数．另外，在证明垂直植被指数PVI和转换型土壤调整指数TSAVI对LAI预测能力的同时，发现利用RVI（810，510）、DVI（810，560）和PVI3个植被指数共同推算小麦LAI的准确度更高．Based on the change patterns of leaf area index （LAI） and canopy spectral reflectance of wheat at different growth stages and nitrogen application rates, this paper investigated the relationships of LAI with canopy reflectance and spectral parameters, and brought forward the sensitive spectral parameters and quantitative equation for predicting wheat LAI. The results showed that with increasing nitrogen application rate, wheat LAI and its canopy reflectance at near infrared （760 - 1 220 nm） increased, whereas the reflectance at visible band （460 -710 nm） decreased. From jointing to maturity, the LAI and the reflectance of short hands in near infrared increased initially and decreased then, whereas the reflectance of visible light and long bands in near infrared was in adverse, with the lowest value appeared at booting stage. Wheat LAI was negatively correlated with the reflectance of visible light, but positively with that of short bands in near infrared, with the highest correlation coefficient at 810 nm. It was proposed that wheat LAI could be well monitored by vegetation indices RVI （810, 510） and DVI （810, 560）. PVI and TSAVI were proved to be the spectral indices in monitoring wheat LAI, and higher accuracy was obtained with combined RVI （810,510）, DVI （810,560） and PVI.

关 键 词：小麦 叶面积指数 冠层反射光谱 光谱指数 定量关系 

分 类 号：S512.1[农业科学—作物学]