Abstract:

The heavy metal elements contents in stream sediments provide the evidences for evaluating the soil-contaminated degree in the mining area. And they are also used to predict the potential of the mines. Based on adsorption mechanism of hydroxyl groups in the stream sediments and free positive ions, in-situ hyperspectral measurements are analyzed to make sure that the best relevance between the soil spectral variables and soil heavy elements concentrates is on the wavelength of 500-780 nm and 2 100-2 300 nm. Thus the regression equations for the field spectral features and metal element concentrations are determined to estimate the heavy metal element contents. The inverse distance weighting method is employed to retrieve the heavy metal contents, Cu and Zn, in stream sediments successfully. And the R² of Cu is 0.618 and the R² of Zn is 0.636. The results show that the heavy metal elements contents in the mountain and forest regions are lower than what in the middle reaches of the streams and the content has a rising trend along the river flowing direction. Furthermore, there exists a high-value anomaly zone in the middle and lower reaches, which provides the evidence for future investigation.

Key words: hyperspectra, river sediments, soil heavy metal, spectral feature, inversion