The comparison of quality control standards for land reclamation between China and the USA: A case study of grassland surface coal mines

Mineral resource extraction causes serious damage to land ecology and environment, therefore a perfect reclamation quality standard is crucial to the construction of ecological civilization in mined area. It is important to optimize the land reclamation quality control standards by revealing the differences in their methods and contents between China and the USA. This study systematically compared the quality control standards for land reclamation in the northern grassland region of China and Wyoming, in terms of reconstruction of landform, soil, vegetation, and hydrology. The result shows that the geomorphological reconstruction does not focus enough on the restoration of pre-mining landscape and landscape coordination, the soil reconstruction index system is comparatively weak, the control of vegetation reconstruction is limited to quantitative values of measurable indicators and does not considering the pre-mining plant growth, and there is a lack of control standards for hydrological restoration quality. The study proposes the following improvement through a point-by-point approach: (1) adjusting the parameter range of terrain indicators to control the terrain restoration to approximate the pre-mining landscape; (2) enriching the soil quality control index system according to the mining species and reclamation direction; (3) improving the control standards of vegetation type and reconstruction time frame, setting the pre-mining reference area and using mathematical statistics to verify the reclamation quality; (4) increasing the control standards of water resources restoration according to the pre-mining information; (5) promoting the standards to the national level. The results of the study can provide a theoretical basis for scientific guidance on quality control of land reclamation and improvement of indicating reclamation success.