不同地类春小麦拔节期冠层光谱与叶绿素差异研究

为实现对不同地类春小麦叶绿素含量的无损估测，通过分析春小麦冠层光谱与叶绿素含量的相关性，以及对其红边拐点位置与叶绿素含量做回归分析，分别建立了水浇地和旱地春小麦叶绿素含量估测模型并检验了模型精度。结果表明: (1) 拔节期水浇地和旱地春小麦叶绿素含量差异较大，且前者明显大于后者。虽然各地类春小麦光谱反射率与叶绿素含量均有很好的相关性，但旱地春小麦的相关性在可见光和近红外波段均低于水浇地。(2)在可见光范围，旱地春小麦冠层光谱反射率高于水浇地，而在近红外区则相反。阴坡地由于土壤水分高，春小麦长势较好，冠层光谱特点与水浇地差异不大。(3)建立的不同地类春小麦反射光谱红边拐点位置与叶绿素含量的监测模型表明，水浇地春小麦叶绿素含量的监测可用线性模型，预测精度达94.06%。而旱地则宜用二项式模型，预测精度为97.15%，比其线性模型高10.48%。

Study on the Difference in Canopy Spectral Reflectance and Chlorophyll Content of Spring Wheat at Jointing Stage in Different Land

Taking chlorophyll content, seedling height, blade width and canopy spectral reflectance of spring wheat at jointing stage in different lands as data source, by analyzing the correlations between canopy spectral reflectance and chlorophyll content, making regression analysis for red edge inflection points of canopy spectral reflectance and chlorophyll content of spring wheat, the chlorophyll content monitor models of irrigated and dry land were established respectively. The results showed that there is a significant difference in chlorophyll content of spring wheat, with chlorophyll content of irrigated land much higher. Although there is a good correlation between wheat canopy spectral reflectance and chlorophyll content in the two lands, the correlation of dry spring wheat is lower than irrigated land in visible light and near infrared band. In the visible region, dry spring wheat canopy spectral reflectance is higher, inverse in near-infrared region. Due to high soil moisture, the dry-land spring wheat grows well and there is little difference from irrigated land. The monitor model of red-edge inflection points of canopy spectral reflectance and chlorophyll content of spring wheat at different lands showed that irrigated land wheat is available for linear model, The estimated precision is 94.06%, but dry land is suitable for binomial model, The estimated precision is 97.15%, 10.48% higher than linear model.