The Study On Sedimentation Of Main Channels In DengKou YangShui Irrigation District Of Inner Mongolia

The DengKou YangShui is a larger Irrigation District in Inner Mongolia,It is an important food production base.The backbone project of YangShui Irrigation was built in the last century.After many years of service,the channels silte up heavily.In recent years,due to the drastic reduction in the volume of water from the Yellow River and the national regulation for the use of water along the Yellow River and the water and sediment conditions of the Yellow River changing,the inlet of the pumping station siltes up heavily and the depth of the river channels is smaller than before.As a result,the operation of the pumping station enters into a vicious cycle mode,the channel silting up causes higher water level and smaller flow,the higher water level and smaller flow causes silting up more heavily.for the long-term development of the irrigation district,it is of great significance to analyzing the factors influencing sediment deposition in the channel,proposing measures for managing the siltation of the channel,improving the efficiency of water utilization in the irrigation area,and fully playing important role of the irrigation district.The main conclusions of this article are:1.bigger sand in which diameter is more than 50?m takes about twenty percent in the sand flowing into the main channel.This part of sediment is one of the causes of sediment deposition in the main channel.2.Supposing the condition of the incoming sand and the incoming water is unchanging,the accretion thickness is positively related to the length of period of out of service of the pump,the thickness is also affected by the stopped time of the pump.3.As the the pumping station operates,there is a certain amount water flow that leads to the thickness of the accretion of sand.4.From the Tuheqi Bridge to the Wudanggou section and From the outlet of pump station to the Dongfu Bridge section,the section of the Tuheqi Bridge to Wudanggou is silted up most heavily,where the slope water factor and the lower flow of water cause accretion more heavily.Therefore,the bottom and the slope of the section need to be renewed.5.by means of installing beam gate in front of the water inlet of the pumping station and sweeping sand at the inlet of the pumping station before the pump started,can effectively prevent sediment from entering the channel;improving the serface of channel,enhancing the slope of channel,improving the operation of the pump,can improve the flowing of sand,play a full role of the Irrigation project.