Abstract:
This study presents a comprehensive review of the land subsidence cause, mechanism, geohazard and methods to mitigate land subsidence and coastal protection works in the Yellow River Delta. The results demonstrate that the land subsidence in the Yellow River Delta has significant temporal and spatial heterogeneity of both subaerial and submarine areas due to influence of natural and anthropogenic factors. The anthropogenic factors affecting land subsidence in the delta region are groundwater extraction and oil and gas exploitation, but the land subsidence caused by them is regional. During the early stages of the development of the active deltaic lobe, the compaction of neritic sediments was the primary contributor to initial subsidence. Furthermore, combined with the relevant sedimentary age and environment determined by previous studies, we found that the spatial variation in compaction-induced subsidence in the subaerial deltaic area over time is closely related to the historical distributions of the river channels in the modern Yellow River Delta. Land subsidence will cause or aggravate the regional flood disaster of Yellow River Delta and its coastal areas, farmland and water pollution, land drainage difficulty, damaged infrastructure and coastal erosion and other environmental problems, needs to make effective protection of groundwater resources and remedy, building levees and other projects is the current effective mitigation measures. However, the environmental problems caused by the construction of coastal breakwater and other projects and their protective effects are still controversial. Therefore, it is of great importance to formulate effective coastal protection strategies to deal with the environmental disasters in coastal areas caused by the subsidence of the delta under the future of sea level rise.