Typical characteristics of geological hazards and ecological environment of coal base in the bends area of the Yellow River

“The ecological protection and high-quality development of the Yellow River Basin” has now been upgraded to a major national strategy. The bends area (the “几” shaped area, also known as the Jiziwan area) is an important part of the Yellow River Basin, and it is also an important gathering area of China’s coal energy. Now the region has six large modern coal bases, coal production accounts for about 40% of the country, in China’s energy security supply security occupies the “ballast” position. However, the region is located in the western arid-semi-arid region, with fragile ecological environment and poor anti-disturbance ability, which is prone to induce various geological disasters during coal mining and generate ecological and environmental problems such as water level decline, soil erosion, and land sanding, which become the core constraints for the high-quality development of the coal industry in the region. Based on a large amount of previous literature, reports and official statistical data, the geological and environmental characteristics of six national coal bases in the bends area are analyzed, and the main geological hazards and ecological and environmental problems faced by the coal bases in the region are summarized, and their respective development types and typical characteristics are condensed, which show that: (1) The main coal-bearing strata in the bends area are Jurassic and Carboniferous-Permian strata. The regional geological structure is relatively simple, and most of the coal seams are shallow, thick and stable, which is suitable for large-scale industrial mining. (2) The geological hazards of the six coal bases in the bends area are highly susceptible, and the geological hazard development characteristics are closely related to the geomorphological type, mining process and human engineering activities. The ecological hazards of each coal base in the region are mainly ground collapse, landslide and mudslide. (3) There are some differences in the ecological environment problems and the degree of impact among the coal bases in the region, among which, the Shendong and Shaanbei coal bases have the most prominent problems of underground ecological water table caused by coal mining activities; the Ningdong and Shendong coal bases have serious problems of land desertification; while the Shaanbei, Huanglong, Jinzhong and Jinbei coal bases are mainly facing the problem of soil erosion. The study aims to provide fundamental reference to promote the sustainable development of the coal resource bases in the bends area of the Yellow River and realize the ecological protection and high-quality sustainable development of the Yellow River Basin.