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The land subsidence caused by underground mining results in the transformation of water relations in the catchment. The purpose of the research is to determine the impact of the subsidence basin on changes in the water cycle. Detailed research was carried out in the city of Bytom, in the Karb district where one of the most spectacular subsidence basins on the Silesian Upland (southern Poland) emerged. As part of the study, the geological structure of the area was examined and a detailed geomorphological and hydrological mapping was conducted. Cartometric measurements were carried out based on the cartographic material collected. The underground extraction of coal in the study area resulted in far-reaching changes in land forms and in the water cycle. The area has subsided by more than 25 metres compared to the level prior to the commencement of underground coal mining. The subsidence basin caused transformations in the water cycle, primarily local ones. The changes concern all elements of vertical and horizontal water exchange. The resulting depression is an endorheic basin to which water is supplied in a concentric pattern as a result of runoff after atmospheric precipitation. The local flow of shallow groundwater has been clearly disrupted and new pathways for their circulation have formed. [ABSTRACT FROM AUTHOR]

The land subsidence caused by underground mining results in the transformation of water relations in the Silesian Upland, which is located in southern Poland. Detailed studies were conducted in 25 water bodies formed in subsidence basins located on the Silesian Upland. The purpose of the study was to determine the temporal and spatial variability of electrolytic conductivity of the limnic waters retained in the water bodies studied. As part of field work, 12 specific electrical conductivity measurements were conducted using the YSI 6600 V2 multi-parameter sonde. The measurements were conducted once a month in hydrological year 2013. Laboratory tests using the 850 Professional IC ion chromatograph from Metrohm included chemical analyses of the water samples retained in the water bodies formed in subsidence basins. The tests conducted revealed considerable variation in the parameter analysed, both spatial and temporal. Average specific electrolytic conductivity values varied from 157 µS/cm to 2785 µS/cm, minimum values from 100 µS/cm to 1483 µS/cm, and the highest values measured ranged from 187 µS/cm to 4089 µS/cm. Water bodies functions in areas with different anthropogenic influences. The hydrochemical diversity of these water bodies is determined by the nature of their catchment areas. The significant variation in this parameter results from the different ways in which water body catchments are used; the values accurately reflect the diverse impact of human pressure on the aquatic environment of the Silesian Upland. [ABSTRACT FROM AUTHOR]

The Silesian Upland (southern Poland) is an area where underground coal deposits as well as zinc and lead ores are mined (in the past, iron ores were exploited there as well). Subsidence basins form in places where minerals are mined below the ground surface. Purposes of the study included assessing the impact of underground mining on the rate of surface subsidence, examining the conditions in which water bodies form in subsidence basins and determining the role of such basins in shaping habitat conditions and biodiversity. Within the framework of field work, detailed geomorphological and hydrological mapping was carried out, floristic composition was determined and the animals present in the area were characterised. Cartometric analyses were carried out based on the cartographic material collected. Laboratory tests were also conducted with respect to both water (using the potentiometric, spectrophotometric, turbidimetric and flame photometry methods) and sediments (using sieve analysis, the combined areometric-sieve method, INAA and ICP). The study revealed that in the region, a total area of more than 1000 km² is threatened with ground deformation and the depth of some basins exceeds 30 meters. Water bodies at the bottom of subsidence basins exhibit morphometric parameters that depend on the size of the subsidence and their shorelines are most often oval in shape. Very small and small water bodies prevail. A vast majority of them have areas which do not exceed 10 hectares. They are also fairly shallow (usually up to 2-3 metres) and greater depths are very rare. Water bodies in subsidence basins alter the local water cycle significantly. These hydrographic phenomena are undoubtedly a new element that contributes to changes in the direction of water migration in the area in question. The water bodies examined were subject to transformations at each stage of the development of the subsidence zone. It has been found that they set a new erosion base level and act as local sedimentary basins. The bottom sediments accumulated in such water bodies are significantly contaminated, particularly with heavy metals such as lead, zinc and cadmium. The studies conducted have demonstrated that these water bodies may fulfil functions similar to natural lakes. The changes triggered by land subsidence affect the evolution of vegetation, and in the final stage, aquatic and land vegetation ecosystems are shaped. In the wake of these changes, many new animal species, both vertebrates and invertebrates, migrate into the area. [ABSTRACT FROM AUTHOR]