Identifying the spatio-temporal evolution and driving mechanisms of ecosystem service value in high groundwater table coal mining areas

In coal mining areas with high groundwater tables, surface subsidence has emerged as a non-negligible phenomenon, stemming from long-term coal mining activities. Employing the Huainan mining area as an exemplar, this research meticulously examines the temporal and spatial attributes of ecosystem service value (ESV) across distinct timeframes of 2005, 2010, 2015, and 2020, utilizing the refined equivalent factor approach in conjunction with spatial analysis methodologies. To delve into the primary forces driving the observed changes, the optimal parameter-based geographical detector (OPGD) model is subsequently utilized as a tool for analysis. Lastly, the study delves into the trade-offs and synergies existing between four exemplary services at the grid level, utilizing Spearman correlation coefficient and bivariate spatial autocorrelation. The findings suggest that: (1) From 2005 to 2020, the total ESV in the Huainan mining area demonstrated a general increasing tendency, primarily attributed to the increase in waters. (2) Throughout the research period, the ecosystem service functions in the coal mining area all exhibited relatively significant hydrological regulation and waste treatment capabilities. (3) Vegetation factors significantly influenced the ESV in the Huainan mining area. (4) The Huainan mining area predominantly exhibited synergistic effects among ecosystem services, with the most pronounced synergy occurring between cultural services (CS) and regulating services (RS). All services were transitioning towards an enhanced trend of synergistic effects. (5) Significant spatial variations are present in the observed trade-offs and synergies among diverse ecosystem services. The aforementioned research findings will provide scientific theoretical guidance for rational mining activities and ecological environmental governance in coal mining areas.