铀矿区植物生物地球化学效应特征及波谱响应机制研究

The shielding effect of vegetation is the difficulty for remote sensing information extraction and application in vegetation coverage area . Our previous research showed that Plants growing in the soil with high heavy metal element content, such as pinus massoniana 、eucalyptus 、 poison sumac and liriodendron, the heavy metal element content, pigment content, reflectance spectra characteristics and cellular structure mutation is different from the Plants growing in the normal soil, and has a certain corresponding relationship between each other. Based on this findings, the project select the advantage plant as the research object in GuangDong XiaZhuan Uranium mining area, combined the experiment research and mathematical modeling, through the combination of rock-soil-plant (roots, stems, leaves) system sampling and spectrum synchronous test, combined with field heavy metal plant stress test and laboratory analysis, research the synergistic effect and plant spectral response fine features of the Uranium mineralization related U and associated heavy metal element combination plant stress, explore the corresponding relations between Uranium area geochemical anomaly - biogeochemical effect - plant spectral variation characteristics; Through the many factors and many parameters of nonlinear fitting, establish the high spectrum biological geochemical anomaly information identification model and related to the Uranium mineralization in high vegetation coverage area, it provide theoretical and technical support fot hyperspectral remote sensing mineralizing anomaly information extraction and has the important theory and application value.

植被的屏蔽效应是植被覆盖区遥感信息提取与应用的难点。我们前期研究发现，重金属异常土壤上生长的马尾松、桉树、盐肤木和鹅掌楸等植物叶片重金属元素含量、色素含量、细胞结构和反射波谱特征等出现一定程度变异，并且相互之间有一定对应关系。在此基础上，本项目以广东下庄铀矿区优势植物为研究对象，实验研究、数学模拟相结合，通过岩石—土壤—植物系统采样和波谱同步测试，结合野外重金属植物胁迫实验和室内分析模拟，研究与铀矿化相关的重金属多元素组合植物胁迫生物地球化学效应特征及植物波谱响应机制，探索铀矿（化）区地球化学异常→生物地球化学效应→植物波谱变异特征的对应关系；通过多元素、多参数非线性拟合，建立与铀矿化相关的高光谱生物地球化学异常信息识别模型，为高植被覆盖区遥感地质、环境信息提取提供理论和技术支撑，具有重要的理论和应用价值。

植被覆盖区，植被的屏蔽效应是遥感地质信息提取与应用的关键。本项目以广东下庄铀矿和云南马场菁铜矿为研究区，系统采集矿区和背景区土壤、植物样品，分析重金属元素、生化参数和波谱特征，统计分析和数学模拟结合，研究重金属异常区植物生物地球化学效应特征及波谱响应机制，服务于植被覆盖区遥感地质信息提取。研究发现：矿区主要植物对重金属具有一定富集作用，植物叶片中重金属含量与色素含量具有相关性，重金属异常会导致叶片细胞产生变异；提出了基于EEMD分解植物波谱特征参数增强提取方法，结合PROSPECT+SAIL模型获取了植物冠层波谱模型；采用环境卫星HIS数据，运用上述方法成功提取了马场菁矿区Cu、Mo、Pb和Ca异常。项目研究将遥感技术和植物地球化学结合，丰富和完善遥感生物地球化学理论和方法，具有较高的科学意义和实际应用价值。