Soil Eco-Hydrological Responses to Mining-Induced Ground Fissures and Vegetation Types in a Semi-Arid Coalfield

Ground fissures induced by coal mining severely disrupt eco-hydrological processes in semi-arid regions. To elucidate the underlying coupling mechanisms between fissure physical disturbances and plant–soil system regulation, this study conducted in situ soil infiltration measurements and daytime micro-lysimeter water-loss observations across four distance gradients (20, 50, 100, and 200 cm) from fissures under four surface cover types in the Shendong coalfield. Vertical soil moisture profiles (0–180 cm) and microscopic pore architectures were also reconstructed. Under the summer sunny-day conditions examined, steady infiltration and daytime micro-lysimeter water loss generally increased toward the fissure, indicating a spatially localized enhancement of water entry and atmospheric water loss. The observed transition occurred between 100 and 200 cm, although the current distance design does not permit a universal threshold to be defined. Deep soil moisture beneath A. desertorum was lower at 150–180 cm near the fissure; this pattern may reflect the combined effects of fissure-facilitated drainage and root water uptake. BSC-covered surfaces exhibited relatively low infiltration and daytime water loss, consistent with a surface-sealing and moisture-buffering effect reported in previous studies. These findings provide preliminary field-based evidence for spatially differentiated restoration around mining-induced fissures, although the proposed management implications require validation through long-term and multi-season field monitoring.