不同生育期倒伏胁迫下玉米叶面积指数高光谱响应解析

Analysis of Hyperspectral Response of Maize Leaf Area Index under Lodging Stress under Different Frowth Stages

为研究倒伏胁迫下不同生育期LAI高光谱响应模型,提高LAI高光谱响应模型精度,获取不同生育期倒伏玉米LAI与冠层光谱反射率,采用6种传统变换方式对高光谱反射率进行处理,构建不同生育期倒伏玉米LAI分期与统一响应模型。研究结果表明:LAI能够直接反映玉米受倒伏胁迫程度及自身恢复能力;传统光谱变换有利于提高光谱同LAI的敏感性及模型响应精度;不同生育期倒伏玉米LAI分期响应模型优于统一响应模型。该结果可有效诊断倒伏胁迫下的玉米叶面积指数,为实现不同生育期倒伏玉米长势精确监测提供理论依据和技术支撑,对玉米倒伏胁迫灾情监测可提供必要的先验知识。

In order to study the hyperspectral response model of LAI in different growth stages under lodging stress and improve the precision of LAI hyperspectral response model,LAI and canopy spectral reflectivity of lodging maize at different growth stages were obtained. Six traditional transformation methods were used to deal with hyperspectral reflectivity,and the LAI stages and unified response models of lodging maize at different growth stages were constructed. The traditional spectral transformation is beneficial to improve the sensitivity of spectrum and LAI and the precision of model response. The LAI stage response model of lodging maize at different growth stages was superior to the unified response model. LAI staging monitoring model of lodging in different growth stages is better than unified monitoring model. The results can effectively diagnose the maize leaf area index under lodging stress,provide theoretical basis and technical support for accurate monitoring of lodging growth in different growth stages,and provide necessary prior knowledge for maize lodging stress monitoring.