Estimating Sediment Moving into the Yellow River Based on Moving Process Analysis

The sediment moving into the Yellow River has decreased in recent years. For instance, the measured annual mean sediment amount at Tongguan station showed a sharp decreasing trend from 15.9 x 10(8) t/a during 1919-1960 to only 2.5 x 10(8) t/a during 2000-2015, a change of 84%. This led to an increased interest in the movement of sediments into the Yellow River. However, the results and conclusions were quite different due to different data and methods used in different studies. Consequently, no widely acceptable understanding existed regarding the sediment movement into the Yellow River. In this study, firstly the main process of sediment moving into the Yellow River was analyzed in the area where the sediments mainly yielded due to hydraulic erosion, gravitational erosion, and sediment transport by water flow in the riverbed. Then, referring to soil erosion as the "three lines of defense", the effects of water and soil conservation projects were discussed to estimate the amount of sediment moving into the Yellow River. Considering the effects of water and soil conservation projects, climate change, and human activities, the sediment in the Yellow River used in engineering design should be between 8 x 10(8) and 12 x 10(8) t/a for safety purpose, and at least 10 x 10(8) t/a for suggestion.