Identifying the reuse patterns of coal mining subsidence areas: A case-study of Jixi City (China)

Abandoned coal mine subsidence areas not only result in land resources wastage and ecological destruction but also disturb the order of space within the urban and rural areas, making it crucial to rehabilitate them. How to identify the best procedures for subsidence areas, which are scattered on a variety of lands rather than a single location? Our research proposes a new 'evaluation + clustering' methodology and took 95 subsidence areas in Jixi as an example. LANDSAT-8 images and modified normalized difference water index (MNDWI) were used to identify the status of collapsed area water bodies. Reuse suitability evaluations were done in terms of ecological protection, urban construction, and agricultural production using a multi-criteria evaluation (MCE) based on a geographic information system (GIS). Then k-means clustering was used to classify the areas to identify their reuse pattern and model. The results show that the degree of subsidence is low with 78.25% of land scarcely wet. The suitability assessment values for rehabilitation as construction and agriculture are high, indicating the lands are suitable for reuse. 619.12 hm² of subsidence areas located in a convenient place and surrounded by different kinds of lands are suitable for multiple uses, 1000.48 hm² of those are appropriate for ecological reuse, namely water, land or forestry, their subsidence being severe and most of them located on mountains or near to the edge of built-up areas. An estimated 630.18 hm² located near the main road and inside the planning land boundary are suitable for parks, industrial land, and other construction lands. A further 11,176.94 hm² could be used for farmland and other agricultural lands.