Construction of landscape ecological network based on landscape ecological risk assessment in a large-scale opencast coal mine area

The comprehensive effect of multi-source factors changes the landscape structure and reduces the quality of landscape ecology in large-scale opencast coal mine area, resulting in an ecologically fragile environment. Landscape ecological quality directly affects the flow and transmission of ecological functions, which is an important factor in the construction of landscape ecological network. In the study, based on the Landsat remote sensing images of 1986, 1996, 2000, 2009, and 2015 in the Pingshuo opencast coal mine area of the Loess plateau in Shanxi Province of China, the landscape loss index and ecological sensitivity index were selected to establish the landscape ecological risk assessment model, and the spatial and temporal characteristics of the landscape ecological risks from 1986 to 2015 were analyzed. Considering the impact of landscape ecological quality on ecological resistance, the Minimum Cumulative Resistance model (MCR) was applied to build a landscape ecological network based on the landscape ecological risk assessment in 2015 to identify the important ecological elements, and the complex network method was used to analyze the structure of landscape ecological network. The local risk level of the study area reduced with opencast coal mining; however, the overall risk level was improved with conducting land reclamation. The high-risk area showed a trend of spreading from southwest to northeast; the risk of the peripheral areas of urban construction land and mining land was relatively high, while that of the forest and grassland area was relatively low. The risk change of the study area was mainly affected by the mining scale, urban expansion, conversion of farm land to forest and grassland, land reclamation, and village relocation. Through the complex network method, the energy flow fluency and the relationship between nodes were enhanced after the optimization of the landscape ecological network, and the ecological elements for specific land use protection were identified. The research results can provide scientific basis for the optimization of landscape pattern and the construction of ecological security pattern in Pingshuo opencast coal mine area.