Geoecological monitoring of dangerous local geochemical objects in urban environment by remote sensing

Abstract

For historical reasons the city of Donetsk happened to be the territory of intensive mining and beneficiation of coal territory, so it acquired a unique townscape which organically combines urban developments and giant dumps (more than 50) – most of them are man-made relics of the early industrial era and coal mine construction.

The authors examine the correlation between the salinity of refuse dumps of mining industry with their vegetation dynamics and its metamorphosis based on remote sensing data. In this paper data from the satellite system LandSat 5 TM are used for the summer and autumn periods. 11 refuse dumps were selected for the research. The use of satellite data of LandSat 5 TM for estimating landscape-geochemical characteristics of refuse dumps rocks and processing plants in Donetsk has showed the perspective of this scientific method in relation to other objects that undergo complicated processes of landscape-geochemical transformations. The effectiveness of index calculation Normalized Difference Salinity Index (NDSI) and Salinity Index (SI) was confirmed by calibrated digital images of refuse dumps undergoing geochemical transformations.

Moisture Stress Index (MSI) and Normalized Difference Vegetation Index (NDVI) turned out to be effective. Comparison of indices NDVI, which was calculated for particular refuse dumps on different dates of the summer-autumn period within 15 years, gave an opportunity to establish the trends of overgrowing the refuse dumps with natural vegetation, including those which may indicate the geochemical activity of rocks.

The analysis has showed that refuse dumps with a relatively-reduced salinity are characterized by partial overgrowing, whereby, according to observers, an air-water regime of the substrate is changing, and its moisture content is one of the main conditions for the further development of the vegetation.