Water Resources and Industry (Dec 2021)
Comprehensive method of assessing the flood threat of artificially drained mine subsidence areas for identification and sustainable repair of mining damage to the aquatic environment
Abstract
The effects of mining, apart from surface subsidences and deformations, are forced flows of surface and underground waters, lasting many decades in the mining areas. Natural water flows should be restored by mining entities and/or their legal successors in the process of the mine closures. Such action is tantamount to a restoration of the previous state in the sense of repair of damage to the environment and surface infrastructure. Then, under natural water flows conditions, such mining areas may become flooded, often quite extensively. This paper describes a comprehensive method for flood threat assessment of artificially drained mining and post-mining areas after the restoration of natural water flows. The subject of this research is the surface of a single mine subsidence area. The term mine subsidence area (MSA) is defined as that part of the rock mass containing solid mineral deposits and the above surface affected by continuous and discountinuous deformation (as currently legally defined in terms of range and intensity). This method, together with simultaneous measurements of water levels at outflow places at the MSA boundary allows for an useful way of mapping the MSA surface. This has been developed to fully identify the true extent of mining-induced damage to the MSA aquatic environment. It introduces innovative hydromorphological elements of the MSA. These allow zoning of the MSA surface while taking into consideration future drainage works and/or projected mining subsidences inside the MSA. These spatial hydromorphological maps of the MSA identify the framework of permanent and occasional flooding and constitute the final result of this method. It is an universal tool for sustainable water management and quantitative evaluation for extraction of minerals.
