Agricultural suitability assessment and rehabilitation of subsided coal mines: a case study of the Dawu coal mine in Jiangsu, Eastern China

Land-use suitability assessment crucial is for coal mine rehabilitation planning, especially for the coal mines that have undergone varying degrees of mining subsidence. In this study, we present an assessment on the suitability of crop cultivation in the Dawu coal mining district in NW Jiangsu province, Eastern China. Distribution of local land subsidence is delineated with topographic analysis, and the weight-of-evidence (WoE) suitability assessment has encompassed various factors including the conditions of soil (e.g., acidity and porosity), groundwater level, irrigation and drainage, terrain slope, and land pollution. Consequently, the Dawu district is divided into four categories (high, moderate, low, very-low) of agricultural suitability. Collaborating with the local government agencies (e.g., Land and Resources Bureau and Agriculture Bureau), a land-use plan is proposed. In the plan, the highly suitable areas for agriculture (and the surrounding moderately suitable areas) are allocated as farmlands, whilst the other moderately to lowly suitable areas are allocated as ecological zones for restoring the ecosystem and ecological diversity. The barely suitable areas with severe subsidence are allocated as artificial lakes, which also serve as reservoirs for farmland irrigation and drainage. To protect these new farmlands from soil erosion, infrastructure such as embankment and windbreak are also included in our rehabilitation plan. Our study highlights the necessity of forward planning in coal mine rehabilitation.