大坞河流域重金属污染与五节芒光谱效应关系研究

The relationships between heavy metals pollution and spectral characteristics of Miscanthus floridulus in Dawu River basin

以大坞河流域五节芒(Miscanthusfloridulus)可见-近红外光谱以及叶片样本Cu、Zn、Fe元素质量分数监测数据为基础,对研究区内五节芒中重金属质量分数特征、光谱特征及两者的相关性进行了探讨。结果表明:五节芒叶片中3种金属元素的质量分数都较高;从上游到下游,五节芒叶片中Cu质量分数整体呈逐渐降低的趋势,五节芒光谱反射率在可见光区和近红外区均增加,红边“红移”(向长波方向飘移)强度逐渐减小;同时,五节芒叶片中Cu质量分数与五节芒可见光区、近红外区光谱反射率积分值呈负相关性,与红边“红移”强度、土壤中Cu质量分数呈正相关。并由此得出五节芒光谱特征中A1、A2、S等3项指标能够较好反映土壤的Cu污染程度,经进一步深入研究,可以将五节芒作为监测矿区土壤Cu污染的指示植物。

The visible-near infrared spectrum of Miscanthus floridulus were measured and the contents of Cu, Zn and Fe in the leaves were analyzed. In the paper, the concentration of Cu, Zn and Fe in Miscanthusfloridulus, the spectral characteristics of them and the relationships between both are discussed. The results indicate that the contents of three heavy metals are high in Miscanthus floridulus. Along the Dawu River Velly, the Cu content of Miscanthus floridulus leaves decreases and the spectral characteristics of the leaves show the disciplinary diversification that the spectral reflectivity ascends and the range of red edge shift decreases. The Cu content of the leaves is correlated negatively with the reflectivity integral and it is correlated positively with the range of red edge shift and the Cu concentration of the surface soil. The three spectrum indices A~, A2 and S of Miscanthus floridulus leaves are correlated significantly with the Cu content of soil. With further study, Miscanthus floridulus can be the plant indicator of Cu contamination in the mine area,