The study on the method of monitoring the restoration effect of heavy metals in mine based on the background value of vegetation

Abstract

In order to monitoring the soil heavy metal pollution, and evaluate the effect of mine ecological environment restoration. This paper use Manganese Mine in Xiangtan as study area, and the image is divided into study area, whole map and control area, statistical and analysis the three regions farmland Vegetation index, get some parameters like Mean Value Difference ratio, STD, STD/MEAM. Based on those data, growth status and heavy metal stress condition of farmland vegetation in Manganese Mining from 1996 to 2016 were analyzed, and the ecological restoration effect in Manganese Mining was analyzed and evaluated by using different years data. The study shows; (1)The Mean of NDVI in the whore map, the study area and the contrast area Mean of NDVI decreased from 0.7906, 0.7978 and 0.7900 to 0.6322, 0.6443 and 0.6181, the difference ratio between the study area and the whole map increased from 0.902% to 1.878%, the study area and the contrast area increased from 0.902% to 1.878%, the STD/MEAN between study area, the whole map and contrast area were increased from 6.543%, 6.906% and 6.582%to 13.503%, 15.755% and 15.839%; (2)The growth of three areas was decreased year by year; the growth of vegetation in study area is better than contrast area and whole area, and the gap was increased year by year, but the increase trend slowed down, and the vegetation growth status in study area is more stable more balance than the contrast area and whole area; (3) Through above study, the effect of ecological restoration in the study area is better than the effect of natural restoration in other area, the ecological restoration project of the Manganese Mine got a good result. The study shows analyst Vegetation index background can monitor the mine ecological restoration effect quickly, and provide reference for mine ecological restoration project.