Hard Coal Spoil Heaps as Complex Geosystems: A Conceptual Framework Based on Physical-Geographical Controls

Hard coal spoil heaps form distinctive anthropogenic landforms and highly dynamic geosystems within post-mining landscapes. Their extreme physical-geographical conditions arise from interactions between heterogeneous substrate properties, distinct geomorphic processes, specific hydrological regimes, microclimatic anomalies, and thermal activity. Although thermal activity and contamination have been widely studied due to their environmental relevance, research on spoil heaps remains fragmented and often focused on isolated components of the system. Integrated, holistic approaches that explicitly link individual subsystems are still largely lacking. This contribution presents a synthesis of current global knowledge and introduces a conceptual geosystem model demonstrating that morphometric variables (local relief, slope, and aspect) act as primary drivers of spoil heap dynamics. The model captures cascading interactions among geomorphological, hydrological, thermal, and microclimatic processes and provides a unifying framework for interpreting spoil heaps as complex anthropogenic geosystems. This approach provides a basis for future interdisciplinary research and supports a more systematic understanding of spoil heap evolution, their environmental impacts, and potential future landscape functions.