水稻镉污染胁迫遥感诊断方法与试验

    Experimental research on remote sensing diagnosis method of Cd pollution stress in rice

    • 摘要: 农田重金属污染是当今世界面临的重大生态环境问题,是普遍关注的重要课题之一。该文通过研究受镉污染胁迫水稻生理生态参数变化的高光谱响应特征来揭示作物污染胁迫遥感信息机理,从而选择水稻镉污染胁迫诊断光谱指数。采用水稻生长季节多个时相的ASD实测高光谱数据和同步获取的作物参数与农田土壤镉含量数据,分析镉污染胁迫水稻生理生态参数如叶片色素含量、水分含量、细胞结构和叶面积指数等与潜在敏感光谱遥感指数的响应关系,确定MCARI、NDWI、RVSI 和RVI为相应的诊断光谱指数。在此基础上建立多级诊断光谱指数空间,用于表达和判别水稻镉胁迫程度。试验结果表明,该方法能有效地诊断水稻镉污染胁迫,但定量估算精度还有待提高。

       

      Abstract: As one of the important topics to universal attention, heavy metal pollution is the significant ecological environment problem around the world. In this paper diagnosis spectral indices for Cd pollution stress in rice were selected, thorough research of hyperspectral response features of physiological ecology parameters change of rice in Cd pollution stress to reveal the remote sensing information mechanism of crops pollution stress. Taking advantage of measured ASD hyperspectral data, we synchronized obtained crop parameters data and Cd content data of farm soil in several time phase of growing season of rice. The response relationships between potential sensitive spectrum remote sensing indices and physiological ecology parameters in Cd pollution stress were analyzed, such as leaf pigment concentration, water content, cell structure and leaf area index(LAI). Then the corresponding diagnosis spectral indices were determined, including Modified Chlorophyll Absorption in Reflectance Index (MCARI), Normalized Difference Water Index (NDWI), Red-Edge Vegetation Stress Index (RVSI) and Ratio vegetation index (RVI). Based on them, multi-level diagnosis spectral indices space was established to represent and distinguish Cd pollution degree in rice. The experiment indicated that this method could diagnose Cd pollution stress in rice effectively, but quantitative estimation precision also waited for enhancing.

       

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