Analysis on the Characteristics of Runoff and Sediment and the Outlook of their Tendency in the Future in the Upper and Middle Yellow River

This paper analyses the characteristics of runoff and sediment changes since 1950 in the Upper and Middle Yellow River. The results show that the runoff and sediment have a tendency of decreasing each decade as a whole, especially in 1980s and 1990s it decreased most obviously. The total runoff in 1990s is the least since 1950, but compared with 1980s, the sediment in 1990s increased a little. This paper simply analyses that the climate change, water consumption of industry and agriculture and engineering of conservancy and water and soil conservation influence on variety of runoff and sediment. Based on these, the outlook of the tendency of runoff and sediment variety in the future in the upper area from Sanmenxia is put forward.