Changes in vegetation cover, moisture properties and surface temperature of a brown coal dump from 1984 to 2009 using satellite data analysis

Abstract

This paper presents an evaluation of changes in the performance of the surface of the Velká Podkrušnohorská dump, a brown coal waste dump, over a period of 25 years from 1984 to 2009, on the basis of satellite data collected by the Landsat satellite. The changes in vegetation cover, surface moisture and surface temperature were evaluated on the basis of the NDVI index (Normalized Difference Vegetation Index), the NDMI index (Normalized Difference Moisture Index) and the Landsat satellite thermal band. Due to the intense piling up of extracted material and the removal of vegetation cover, there was a significant increase in surface temperature and a decline in NDVI and NDMI after the study of the dump territory began. The maximum surface temperatures and the minimum values of both indices were established in 2000. The trend of the changes in these values has reversed since 2000, due to intensive reclamation works as well as natural succession. The results indicate a significant role of vegetation cover in the formation of the surface temperature and moisture parameters, and the transformation of solar energy at the surface. We consider that the removal of vegetation cover over vast areas can have an impact on the regional climate and hydrological regime. Moreover, we recommend that emphasis be placed on this effect when planning structures for mining purposes.