滨海盐土重金属含量高光谱遥感研究

高光谱遥感凭借其极高的光谱分辨率在获取有机质、矿物质等土壤组分定量信息的研究中表现出非凡的潜力。以如东县洋口镇为研究区,通过对土壤反射光谱的测量和同步的土壤化学分析,研究了土壤重金属Cr、Cu、Ni与土壤粘土矿物、铁锰氧化物以及碳酸盐之间的赋存关系。利用光谱一阶微分、倒数对数和连续统去除法对土壤光谱的处理,获得了土壤成分的特征波段,通过土壤重金属与土壤光谱变量的相关分析,并利用逐步回归分析方法,确立了3种重金属元素的最佳遥感模型。结果表明,研究区3种重金属与波长429 nm、470 nm、490 nm、1 430 nm、2 398 nm、2 455 nm处光谱变量具有很好的相关性,在所建立的逐步回归模型中,以一阶微分处理的模型精度最高。研究结果可以为高光谱遥感技术反演土壤重金属含量,进一步应用空间或航空遥感进行大尺度环境污染遥感、遥测信息提取和反演提供技术支撑。

Study on Heavy Metal Element Content in the Coastal Saline Soil by Hyperspectral Remote Sensing

With its high spectral resolution,hyperspectral remote sensing has a great potential in obtaining quantitative information of soil components,such as organic matter,mineral substance.Taking Yangkou town Rudong county as a research area,the coherence between soil heavy metal elements Cr,Cu and Ni and soil clay mineral,iron-manganese oxide and carbonate is studied after soil reflectance spectrums are measured and soil components are analyzed by chemistry methods.Soil spectrums are processed by first derivative,inverse-log and continuum removed methods,then the characteristic spectral wavelengths of soil heavy metal elements are obtained.Given that the best quantitative remote sensing models for 3 heavy metal elements are deduced by stepwise regression after the correlation analysis of soil heavy metal elements content and spectral variables.The results show that 3 heavy metal elements have good correlations with spectral variables at wavelength 429 nm,470 nm,490 nm,1 430 nm,2 398 nm and 2 455 nm,the accuracy of the model for first derivative spectral variable is the highest among the models.The study aims that the content of heavy metal elements in the soils can potentially be quantitatively deduced by remote sensing,and would provide a basis for the evaluation and interpretation of heavy metal and environment pollution on a large scale by the hyperspectral remote sensing.