126 / 2023-06-29 18:49:53

Food-Energy-Water nexus perspective: Beneficial reuse of dredged sediment in mine land reclamation towards supporting the regional Sustainable Development Goals in Eastern China

Mining subsidence; land reclamation; Yellow River sediment; Food-Energy-Water (FEW) nexus; Sustainable Development Goals (SDGs)

Food, energy, and water resources, as fundamental human needs, constitute the core contents to achieving the United Nations 2030 Sustainable Development Goals (SDGs). The primary motivation for coordinating the food-energy-water (FEW) nexus within the coal-grain composite area of the Huang-Huai-Hai alluvial plain in the lower Yellow River of China is the ongoing tension between farmland damage, coal mining subsidence, dredged sediments occupation in terms of the competition for land. The Yellow River sediment filling reclamation technology presents a win-win solution for coordinating FEW nexus by facilitating the mine land reclamation and dredged sediment resources utilization. Based on the theoretical foundations of sediment-based filling reclamation (SFR) in stable coal subsidence areas, geomorphology was used in the reclamation of highly disturbed unstable subsidence sites under repeated or multi-seam mining to engineering ecologically sustainable reclaimed farmland landscapes. Taking the Qiuji coal mine, in Shandong Province, China as an example, concurrent mining and reclamation (CMR) was implied to guarantee the quality and quantity of reclaimed farmland by pre-stripping the topsoil. An approximate subsidence contour (ASC) approach was proposed based on the probability integral method (PIM) for remodeling the dynamic micro-landform of reclaimed farmland. Combined with the GIS-based revised universal soil loss equation (RUSLE) model, the soil erosion rate of each reclamation stage was simulated and evaluated to help guide the dynamic adjustment of reclamation. The objectives of this study are to couple the CMR technology with the SFR technology, and to form the concurrent mining and filling reclamation (CMFR) technology suitable for mining subsidence areas with high groundwater table, multiple coal seams, and superimposed subsidence characteristics in eastern China, and to provide new ideas for promoting mine land reclamation. Meanwhile, offer new insights into integrating the FEW nexus to transform trade-offs into synergies to advance the implementation of the SDGs.