| In recent years,soil heavy metal pollution in mountainous farmland and mines in China has become more and more serious,most of which are based on the unreasonable exploitation of metals in mines.Large quantities of mining lead to the accelerated accumulation of mine residuum and the acceleration of soil erosion,which leads to the increasingly serious soil pollution in mining areas in China.Especially in the background of pursuing ecological civilization and high environmental quality development,large area soil pollution is still an urgent environmental problem,so it is particularly necessary to analyze and monitor the mining area pollution environment.With the development of remote sensing technology,remote sensing monitoring can open up a new way for the rapid and accurate interpretation of the spectral changes of plants under stress caused by heavy metal pollution.In this paper,changbai larix plants and vegetation in the background area of Hongtoushan-Shishigou mining area in Eastern Liaoning were taken as the research objects to obtain vegetation information data in the study area through remote sensing image interpretation.By means of remote sensing monitoring and the large area pollution and abnormal dynamic monitoring of vegetation,use the easy access to such as Landsat-8 series of multi-spectral remote sensing data,the system research from April to November,different phenological phase of reflection spectrum change rule and the soil pollution of the coupling relationship between mineralization area,for abnormal plant monitoring using remote sensing image is a kind of effective technical means,not only can solve the problem of large area pollution plant monitoring,and analysis of abnormal plants of spectral variation law with time can be contoured on the land surface of concealed pollution area,to solve the problem of soil pollution,pressing method provides a new idea for mineral resources exploration.The results showed that :(1)A series of sampling points were arranged on the no.4,no.12 and no.20 survey lines in shujigou mining area.Under the influence of copper(zinc)concealed ore bodies,there was a good coincidence between the copper content in the surface soil of the three survey lines and the variation degree of Larix olgensis Henry reflection spectrum.Many characteristic bands of larch,such as red edge,green peak,showed good regularity;(2)In the multi-spectral images,NDVI threshold method and density segmentation method were used to identify the cu-contaminated plants and normal plants in the background area of the mining area in the study area,and actual ore points were used for verification.It was believed that the most favorable method for delineation of contaminated plants was the combination of NDVI threshold method and density segmentation;(3)The multi-spectral images in multiple periods from April to November are the data sources.After screening,it is believed that the multi-spectral images in early June are the best period for reflectance spectrum detection and classification of plant pollution degree.Band 1～ Band 7 well reflects the law that the reflectance of mineralized area is lower than or almost close to the background area from April to November;(4)The optimal Band combination was selected to define copper-stressed plants in the study area,and it was believed that Band 3,Band 5 and Band 6 had great differences and good spectral information independence,and it was easy to obtain the pure end elements of contaminated plants,so the amount of pollution information was relatively large;(5)Four common vegetation indices are selected and analyzed to delineate the vegetation in the background area and mineralized area,it is found to be feasible;(6)The sentinel-2A image was used as the data source.The sentinel-2A image had a good anastomosing relationship with the delineation of abnormal plant areas and mineralized soil areas,and landsat-8 image had a good anastomosing relationship with the delineation of abnormal plant areas and mineralized soil areas. |
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