Land subsidence in the modern Yellow River Delta and its impacts upon its evolvement
现代黄河三角洲地面沉降对洲体演变的影响

The causes for the evolvement of the modern Yellow River Delta have been a main topic for a long time. Recent studies have shown that the entire modern Yellow River Delta has experienced complicated patterns of land subsidence. Our study analyzed the characteristics and impacts of the land subsidence, and particularly discussed the effect to the development of the delta. Factors including structural geology, the sediment consolidation, and human activity have simultaneously affected the pattern of land subsidence over the highly developed Modern Yellow River Deltaic area but with various degrees of effect as a function of region and time. Subsidence has induced marked environmental geologic changes, including coastal erosion, storm surge disaster enhanced, and salt water incursion. Its impact is particularly critical because of the flat low-lying topography and the presence of a thick soft silt layer at the ground surface. The accumulating land subsidence can change the surface slope, consequently influencing the riverbed and estuary evolution. Additionally accumulating land subsidence has increased the rise of the relative sea level, changed the models of coastal erosion, forced the coastline retreat landward, and narrowed the tidal flats at an accelerating rate with the strengthened hydrodynamic action. The land subsidence in the Yellow River Delta will continue owing to the time-dependent consolidation behavior of the soft silt layer and anthropic activity; therefore, the further research on the land subsidence is urgently needed to be actualized.