A New Classification of Open Pits and their Remaining Gaps in Terms of Hydrogeological Conditions

Abstract

As open-pits occupy the land only temporarily, post-mining planning for sustainable land reuse represents an important stage and it can be done since the pre-exploitation stage. There are more possibilities to reuse former open pits depending on the nature and location of ore deposits. Coal open-pits are often reused as artificial lakes. Depending on local hydrology and hydrogeology the flooding process of former open-pits may be done naturally or artificially (combined). Reuse of the remaining gaps of open-pits requires a good evaluation of possibilities and limitations specific to the area. The classification of open pits and their remaining gaps in terms of hydrogeological conditions is necessary for a better post-mining planning of the area. This paper proposes a multicriterial classification of open pits and their remaining gaps taking into account the hydrogeological conditions and the action of some hydrogeological parameters that have an important contribution in establishing the approach to their flooding process. The most important hydrogeological conditions of the region are investigated (the hydrogeological structure, types and number of aquifers, nature of aquifer rocks, hydrodynamic characteristics of the region) and the results are processed for the development of a multicriteria classification. Depending on the results of hydrogeological classification of open pits and their remaining gaps, the possibility of natural and/or artificial flooding can be established or, contrary, the need to consider a different reuse direction, other than flooding. The proposed classification is useful as in literature no multicriteria classification exist, most of them being focused on single criterion classification. In this paper, more open-pits and their remaining gaps were analyzed from a hydrogeological point of view and classified based on the proposed classification which takes into account more evaluation criteria.