Ecological space optimization of plain coal mine county based on ecological suitability analysis

Abstract: In the process of rapid urbanization of mine areas，the ecological space around these city is being constantly swallowed up. The collapse of coal mine area as a difficult ecological problem has become an important factor restricting the social, economic and ecological sustainable development of the coal mine area in the plain. However, quite a few coal mine areas tend to focus only on the ecological restoration of the subsidence area, resulting in a good ecological restoration in the subsidence area and a poor ecological construction in the non-collapsed area. There are few studies on the ecological suitability of the coal mine areas, and the evaluation system is constructed one-sided. In this paper, 10 indicators were selected from the 3 aspects of natural ecology, feature limitation and human disturbance by the analytic hierarchy process (AHP) to construct an ecological suitability analysis system, based on the characteristics of the coal mine area in the plain. Taking Yuncheng County, Shandong Province as the studg area, and the ecological factor superposition method was used to calculate the ecological suitability of the studg area. The studg area was divided into 5 divisions according to the Natural Breaks (Jenks). Meanwhile, in order to avoid the fragmentation of ecological zones, the minimal cumulative resistance (MCR) model in landscape pattern analysis was introduced to construct the ecological network of the studg area: the largest ecological suitability patch of each township was selected as the ecological source site, the reciprocal of ecological suitability comprehensive index was taken as the ecological cost and the ecological corridor was calculated. By implementing different construction strategies for different important zoning to provide targeted optimization suggestions in choosing the direction for ecological restoration construction and ecological protection construction of Yuncheng County. The results were as follows: The most unsuitable area, the unsuitable area, the barely suitable area, the suitable area and the most suitable area were 90.66, 274.99, 643.42, 530.64 and 103.66 km2 respectively. The most suitable area was mainly concentrated in the northwestern part of the county and the most unsuitable area was concentrated in the area of collapsed waters or high level of urbanization. According to the selection principle, a total of 14 ecological source points were selected to construct 43 ecological corridors in the county. The county had established an ecological network framework of “point-line-face”. The current ecological spatial structure of the study area was unevenly distributed: the ecological structure was complex in the northwest, sparse in the south and deficient in the middle. The most unsuitable area should be as the core of ecological restoration and the most suitable area should be as the core of ecological protection to create a complex networked ecological support system. Optimize all grades by ecological measures such as constructed wetland construction, green space construction, and ecological river construction. And improve the stability of ecological network structure through the protection of ecological source areas, the construction of small ecological blocks, the construction of ecological corridor buffers, and the optimization of ecological matrix area, thus providing a basis for regional ecological space optimization. The study results will provide a reference for the ecological space optimization in the county of plain coal mine.