ANALYSIS OF UPSTREAM WATER-SEDIMENT VARIATION AND SCOUR-SILTING ON NINGXIA-INNER MONGOLIA REACH OF YELLOW RIVER

摘要

This paper analyzes the relation between the reservoir operation of Upper Yellow River and the scour-silting of Ningxia to Inner Mongolia reach. The impoundment of the upstream reservoirs is one reason for the scour-silting of Ningxia to Inner Mongolia reach. The downstream channel is scoured while sand is retained in the upstream reservoirs. The reach is deposited while inflow is reduced. The above 80% coarse sand large than 0.1mm is deposited on the Shizuishan-Hekou course from Ningxia to Inner Mongolia reach. This part of sand originates mainly from wind-blown sand of Kubuqi desert. The analysis of typical years and long duration of water-sand flowing process indicates that deposition of sand large than 0.1mm in this reach is not closely related with the amount of flowing sand. The main way to decrease silting is the harness of the desert and the reduction of wind-blown sand from ten tributaries into the Yellow River.