Study On Dam Canal Joint System And Density Flow Flush Sediment Of Kizil Rese Rvoir

Sediment deposition occupies the capacity of reservoir and reduces the effective storage capacity, thereby affecting flood control and power generation. Weigan river, where Kizil reservoir is located in, is a mountainous sandy river. Kizil reservoir’s sedimentation problem is particularly outstanding in the 20-year running, the actual amount of silt deposition amount is far more than designing. The main reason for Kizil reservoir sedimentation is that the sediment deposition near the Fish-mouth of Heizi River tributary formed the "Sediment Retention sill" to obstruct the Muzat river main stream. In order to solve this problem, the experiment program of embankment canal combined with artificial supplementary is put forward, and the optimum combination and optimal conditions is determined by the test, then applied to reservoir area. It’s actual effect shows that Dam canal joint system can effectively move the Heizi River tributary water from the right bank to the left bank, through the artificial discharge canal into the flood discharge and discharge open canal in front of the dam, effectively solve the tributary’s blocking action to the main stream.Density current desilting is very important way in the high sediment laden f low in the reservoir, especially in Kizil reservoir. Kizil reservoir can’t completely open free sediment discharging because of taking multiple scheduling tasks, and it can’t keep a low water level operation for long time, so backwater make use of the density current desilting become really important. The reservoir ’s incoming sediment and inflow are both big and distribute uneven, and Heizi River ’s reservoir inflow suspended load is mainly silt, easily carried by water. For better use of density current desilting, research and quantitative analys is the influence factor of density current in reservoir area. When the water level before the flood season is about 1141.3m and the water level at the end of the flood season is about 1147 m is the best sediment delivery time of density flow; when the flow into reservoir is more than 100m3/s and sediment concentration of reservoir inflow is more than 10kg/m3 density current is easy to happen. Take the density current happened on July 21, 2011 as an example, calculat e the movement process of density current, confirm its dive location data, propagation distance, time, etc, by comparing the calculated values and measured values, the result shows that the calculation results are accurate. The Kizil reservoir ’s carrying capacity equation of density flow and propagation time formula is deduced, to calculate the density current’s relevant data on July 28, 2007. The relevant data of this two density current above prove that the effect of density current desilting is gradually increase, further proves the impact of dam canal joint system built- in. Take Kizil reservoir as research object, to explore the dam canal joint system’s arrangement effect and the density current’s movement rule of high sediment laden flow, this research results can effectively reduce the reservoir sediment deposition and extend the life of the reservoir, and provide a reference to the reservoir manager.