Hyperspectral Remote Sensing Monitoring Of Heavy Metals Pb And Cd Pollution In Water

Aiming at the problems of low spectral reflectance and unobvious characteristic response band in remote sensing monitoring of heavy metal pollution in water,this paper takes Shizhuyuan mining area as an example to carry out hyperspectral remote sensing monitoring of heavy metal pollution in indoor and outdoor water.The specific research contents and conclusions are as follows:Firstly,the multi-concentration pollution standard solution of single heavy metal lead(Pb)and cadmium(Cd)was prepared.On the basis of spectral mathematical transformation,the pollution characteristic bands of heavy metals Pb and Cd in water were obtained by correlation analysis,and the single-band nonlinear and multi-band partial least squares inversion models were constructed to realize the inversion of heavy metals Pb and Cd in water.The results show that the first-order differential and envelope removal can effectively improve the extraction accuracy of characteristic bands of heavy metal pollution in water.The characteristic bands of Pb pollution in water are 554 nm and 748 nm,and the characteristic bands of Cd pollution are 1102 nm and 1137 nm.The multiband inversion model is better than the single-band model.Secondly,this paper selects Shizhuyuan mining area as the research target area,collects 41 groups of water samples,and detects the pollution contents of heavy metals Pb,Cd,Zn,Cu and Fe.The mathematical transformation method and inversion method obtained from indoor experiments are used to obtain the pollution characteristic bands and inversion models of heavy metals Pb and Cd in field water,and verify the accuracy of indoor experimental results and methods.Then,the models and methods are applied to the inversion of the pollution contents of heavy metals Zn,Cu and Fe in the water of the study area,and the heavy metal pollution of water in Shizhuyuan nonferrous metal mining area is obtained and analyzed.The results showed that no Cd pollution was found in Shizhuyuan mining area.The characteristic bands(748 nm and 554 nm)and strong correlation bands(535 nm and 667 nm)of heavy metal Pb pollution obtained from the spectral curve of water samples in the study area after first-order differential transformation confirmed the results of laboratory experiments.The characteristic bands of Zn,Cu and Fe pollution in mining area water are 533 nm,445 nm and 1324 nm,which realizes the inversion of heavy metal content in polluted water samples of Shizhuyuan mining area by indoor experiment inversion model and strengthens the persuasion of indoor experiment.To sum up,this paper proves the applicability of indoor method and model in outdoor by extracting characteristic bands of Pb and Cd pollution in indoor and outdoor water and inversion experiment of pollution content.It is extended to the extraction and content inversion of Zn,Cu and Fe pollution characteristic bands in Shizhuyuan mining area,which provides effective data and model reference for hyperspectral remote sensing field inversion of heavy metal pollution in water and lays a foundation for space remote sensing monitoring.