Characteristics of catchments disturbed by lignite mining—case study of Schlabendorf/Seese (Germany)

Abstract

In the Lower Lusatian lignite mining district, large areas have been mined and recultivated. An even larger area has been affected by groundwater lowering. The specific characteristics of catchments disturbed by lignite mining are presented for the Schlabendorf/Seese region, where a close relation between water issues and open-cast lignite mining exists. In general, this relationship starts prior to mining and persists even after the land is reclaimed. The most obvious feature of this post-mining landscape is the large number of forming post-mining lakes. A further feature is the recovery of the groundwater table. Dry streams and springs now are starting to flow again, and areas with a formerly deep groundwater table are now directly influenced by rising groundwater. The disturbance causes various acidification phenomena. The aeration of pyrite-bearing material leads to a drastic deterioration of the groundwater quality, which affects receiving streams and lakes. Thus there is the tendency for some parts of post-mining lakes to become acid. Additionally, in the marginal areas of the groundwater recovery, acidification of streams occurs, causing water quality problems in ponds and lakes located downstream. The development of each individual water body with respect to water quantity and quality depends on its specific hydrogeological and hydrological setting. The region is experiencing dynamic changes, and shows that the future development of the post-mining catchments is difficult to predict.