Analysis on Hydrologic Regime of Yellow River in Flood Season of 2004

Abstrcat During the whole flood season of 2004(from July to October), the precipitation in all regions of the Yellow River basin is less than or near to the ordinary year, except that the precipitation in the Yiluo River region is more by 10.3% and the precipitation in the Dawenhe River is more by 54.6%. The water and sediment quantities through the main stations are all less than the same period of ordinary year. For example, the peak flood of Longmen and Tongguan Station are only 2 100 m~3/s and 2 140 m~3/s, and they all are the least in history. For maintaining the healthy life of the Yellow River, the third flow and sediment regulation experiment and the first operation in the Yellow River have been completed in this year. On August 22-23, during the first flow and sediment regulation operation, the peak flood occurred in the down-reach of the Yellow River since this flood season, and the peak discharge is 4100 m~3/s in Huayuankou Station, 3 190 m~3/s in Lijin Station. They are all the max discharges since 1998. Meanwhile the discharge in five stations down Gaocun is the max discharge since 1996.