Incorporating ecological risk index in the multi-process MCRE model to optimize the ecological security pattern in a semi-arid area with intensive coal mining: A case study in northern China

High-intensity coal mining has resulted in numerous ecological and environmental problems, and seriously threatens ecological security in China. The identification and optimization of the ecological security pattern (ESP) can facilitate sustainable development while preserving the integrity and stability of ecosystems, which is important for improving ecological security in fragile ecosystems and areas of intensive coal mining. This paper presents an integrated framework for identifying, analyzing, and optimizing ESP in consideration of the core area extracted based on morphological spatial pattern analysis (MSPA), ecosystem services importance, and ecological risk index. The innovative method combines the model of linking different ecological source grades to multi-process minimum cumulative resistance (multi-process MCRE model) and kernel density analysis and includes the following steps: (1) ecological patches are delimited by assessing ecosystem services importance based on the contributions of water resources supply, soil conservation, gas regulation, and habitat maintenance; (2) ecological sources are identified by considering landscape connectivity along with the number and area of important ecological patches; (3) ecological resistance coefficient is determined based on the ecological risk index, which is constructed by coupling the surface drought index, landscape ecological risk index, and mine disaster risk index; (4) ecological corridors are extracted using the multi-process MCRE model, which is based on minimum cumulative resistance (MCR) theory, and the ecological potentials of ecological sources; and (5) the ESP is optimized via kernel density analysis, and regulation zones are defined based on the optimized ESP. Results demonstrate that the optimized ESP in study area included 3326 km² of ecological sources that primarily dominated by grassland, 58 ecological nodes, 827.92 km of group corridors and 308.21 km of landscape corridors; which distribution pattern was “three horizontal, two vertical, and two circles” to ensure continuity of ecological process within study area. The restrictive, protective and key development areas accounted for 17.36%, 59.81%, and 22.83%, respectively; and corresponding planning recommendations were raised. This study not only provides an effective framework to identify, construct, and optimize ESPs in ecologically fragile coal-mining areas, but also purposes the multi-process MCRE model and ecological sources quantification that suitable for global region to achieve the sustainability between resource exploitation, urban development, and ecological protection.