| Land resources are fundamental to the growth of all things. It is the foundation of agricultural production. As the most important part of the land resources, the soil is an indispensable natural resource for human beings. The environment of the soil is closely related to the human production and life, carrying a large number of production materials and the most direct. At present, variety of reasons lead to the phenomenon of heavy metal pollution has seriously damaged the soil environment and soil heavy metal pollution compared to other such as water pollution, air pollution has strong concealment, and not from the outside is very intuitive and pollution mechanism of complex. In many previous studies, the heavy metal pollution in coal mine area is more common. On the one hand, coal mining has greatly promoted the local economic development; on the other hand, because of accumulation of coal mining process, a large number of coal gangue, coal washing wastewater discharge and other reasons, Bring the heavy metals below the surface to the surface, resulting in abnormal migration of heavy metals in soil.In this paper, we took coal mining area as the study area north of Longkou. Under the support of the National Natural Science Fund Project “Sewage irrigation farmland ecological security based on remote sensing monitoring of surface parameters”, Shandong Province Science Foundation of Shandong province “Shandong Province Jiao Jiajin remote sensing survey of environmental geology into the mining area and the surrounding area”, Shandong Province Science Foundation “Research on remote sensing monitoring of Longkou mining area and the surrounding coastal zone”, Shandong Province Science Fund “the Yellow River delta Efficient Ecological Economic Zone sea salt water intrusion investigation and monitoring and early warning system construction”, “Construction project of remote sensing spectral database of land and resources in Shandong Province” and Shandong Normal University master of scientific research and Innovation Fund “ Study on detection of heavy metal content and ecological risk assessment of soil in coal mine area ”. Based on the data of the field soil hyperspectral and the heavy metal content, study on hyperspectral monitoring and pollution assessment of heavy metal content in soil.The main research contents and results are as follows:(1)Taking coal mining area as the study area north of Longkou, 36 soil samples were collected, field spectrum of the field were measured. At the same time, the soil spectral characteristic information was extracted by a variety of spectral transformation methods. Based on the laboratory data of heavy metal content, the model of remote sensing estimation was established. In order to solve multicollinearity among variables, partial least square method wes selected and pricinpal component regression as well as stepwise regression algorithm were abandoned in this study. Results show that Ni, Mn, Pb, Zn, Cr and optimal estimation model using the spectral indices were: second order differential, first-order differential, reflectivity, reflectivity, second order differential and removal of the envelope; also found spectral differential treatment to remove baseline drift and improve the accuracy of the model.(2)Combined with geostatistics and GIS spatial analysis method, the five kinds of biological toxicity significant heavy metal Ni, Pb, as, Zn and Cr in the soil space distribution characteristics of were studied, and according to the result of the analysis of the semi variogram, Kriging interpolation model of optimal point to face dimension expansion, realizes the spatial distribution of the heavy metals in visualization. The results showed that the spatial distribution characteristics of different heavy metals were different, and the spatial variability of Cd and As were greatly influenced by the factors of spatial variation.(3)Based on the correlation analysis of 5 kinds of heavy metals Ni, Pb, As, Zn and Cr, combined with the principal component analysis and spatial distribution map, the five kinds of heavy metal pollution sources were briefly explored by means of the field survey results. Principal component analysis of two principal component factors, due to heavy metal content exceed the national soil environmental quality secondary standard more samples, the basic can rule out into the effects of soil parent material, the first principal component reflects the mainly factors of coal mining, the second principal component reflects the is excessive use of sewage irrigation, pesticides, metallurgical industry production and automobile exhaust.(4)The single factor pollution index method based on Evaluation and weighted average comprehensive pollution method of Longkou Coal Mine 5 heavy metal toxicity significant to evaluate the pollution degree and comprehensive ecological risk assessment, it was found that contaminantion levels of 5 heavy metals followed the order of Cr>Cd>Pb>Ni>As; the analysis of the comprehensive pollution degree show that: 4 soil samples were not contaminated, 14 samples were light pollution, 14 samples were moderately contaminated, 4 samples were severe pollution; heavy pollution areas are mainly distributed in most areas of Longkou Coal Mine Central found the interpolated comprehensive pollution level map, less polluted areas are mainly distributed in Longkou Coal Mining Area in eastern and western part area, and moderately polluted area> lightly polluted area> severe polluted area> uncontaminated area. |
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