Hyperspectral characteristics of chlorophyll content in summer maize under different water irrigation conditions and its inversion

植物叶绿素含量直接影响其光合作用，并与植物的光谱特征密切相关。以夏玉米为研究对象，采用人工控水方法研究了夏玉米七叶期不同灌溉量下冠层叶绿素含量特征及其与光谱特征之间的关系。结果表明：灌溉量越少，夏玉米叶片叶绿素含量越低，冠层光谱反射率越高，绿峰位置"红移"，而红边位置"蓝移"。叶绿素含量与光谱特征参数、植被光谱指数之间存在极显著相关关系，据此建立了冠层叶绿素含量高光谱估算模型，且基于植被指数模型较基于单一光谱特征参数模型模拟效果更好。研究结果可为夏玉米叶绿素含量的快速无损测定以及夏玉米干旱监测提供依据。;Plant chlorophyll content directly affects its photosynthesis and is closely related to the spectral characteristics of plants. In this study, summer maize was used as the research object, and the characteristics of chlorophyll content and its spectral characteristics under different water irrigations of summer maize at seven-leaf stage were studied by the water control method. The results showed that with the decrease of water irrigation, the chlorophyll content of the summer maize canopy leaves decreased and the spectral reflectance of the canopy increased. At the same time, the green peak position was red shifted, but the red edge position was blue shifted. There was a significant relationship of chlorophyll content with spectral characteristic parameters and vegetation spectral index. Based on these relationships, several hyperspectral inversion models of canopy chlorophyll content were established. The model validations indicated that canopy chlorophyll content was simulated better by vegetation index than single spectral characteristic parameter. The results provide the basis for rapid non-destructive determination of chlorophyll content in summer maize and drought monitoring of summer maize production.