Boundary demarcation of the damaged cultivated land caused by coal mining subsidence

Due to the subsidence caused by coal mining activities, the cultivated land in the eastern plain of China has suffered serious damage. Currently, there is no criterion for demarcating damaged cultivated land for crop compensation, land requisition, and/or land reclamation. This paper describes the development of a new method and assessment criterion for determining the boundaries of damaged cultivated land caused by coal mining subsidence. A damage evaluation indicator system is proposed, based on the analysis of the subsidence influence and land damage types. The establishment of demarcation criterion is achieved by comprehensively analyzing the influence of the groundwater depth, surface inclination, chemical pollution, and the visual cultivated land sensitivity (VCLS). To assist the practicality of using this system, a digital elevation model (DEM) and additional information about the surface slopes of the Yanzhou coal mining area are generated; this enables the damaged cultivated land to be classified into three grades. The results reveal that the most important mild-damage boundary for Yanzhou coal mining area can be determined by the 45-mm sinking line, or additional slope greater than 0.5A degrees (inclination is equal to 9 mm m(-1)), or the VCLS value at 0.6; it is feasible for the criterion to be the reference basis for the boundary demarcation.