| The construction of pumped storage power station changes the flood section of the river channel,flow pattern,the effect of local equilibrium between scouring and deposition,raising water level in flood season and decreasing flow rate,the flow force of water and sand carrying capacity dramatically decreases,deposited sediments in the reservoir,rising the bottom of the bank,etc,it can further affect the stability of the river regime.In view of the above mentioned many reasons,it is extremely necessary to evaluate flood control for construction projects in river management.This paper takes the project of Fukang pumped storage power station in Xinjiang as an example,which discusses the question of affecting the flood control in project construction.According to the gist and main content of flood control evaluation,this paper widely collects hydrological,topographic and geological information in the river section of the project,compare two methods,hydrological analogy method and stormwater convergence method,finally,the results of the safer stormwater convergence method are used to push the flood peak flow of the lower reservoir dam site,and obtain the following conclusion:(1)According to the "Atlas of the Biggest Rainstorm in Xinjiang Uygur Autonomous Region",it can be determined when the design frequency of the lower reservoir of the Fukang pumped storage power station is 0.1%,0.5%,1.0%,2%,5%,10%,20%,the 24h design surface rainfall is 180mm,145 mm,130 mm,115 mm,94.5 mm,78.9 mm,63.0 mm;when the design frequency of the upper reservoir is 0.1%,0.5%,1.0%,2%,5%,10%,20%,the 1h design surface rainfall is 72.0mm,55.0 mm,47.8mm,40.6 mm,31.3mm,24.4 mm,17.8mm.(2)The hydrological comparison method can be used to determine when the design frequency of the lower reservoir dam site of the Fukang pumped storage power station is 0.1%,0.5%,1.0%,2%,5%,10%,20%,the design peak flow rates are 306m3/s,269 m3/s,220 m3/s,184m3/s,149m3/s,106 m3/s,74.9 m3/s,48.4 m3/s.(3)Using the storage experience unit line method,it can be determined when the design frequency of the lower reservoir dam site of the Fukang pumped storage power station is 0.1%,0.5%,1.0%,2%,5%,10%,20%,the design peak flow rates are 315 m3/s,274 m3/s,228 m3/s,194 m3/s,158 m3/s,109 m3/s,78.7m3/s,52.2 m3/s.(4)Using the inference formula method,it can be determined when the design frequency of the upper reservoir dam site of the Fukang pumped storage power station is 0.1%,0.5%,1.0%,2%,5%,10%,20%,the design peak flow rates are 106m3/s,89.6m3/s,69.8 m3/s,56.8 m3/s,44.2 m3/s,30.4 m3/s,21.0 m3/s,13.6 m3/s.(5)According to the sediment data of the Baiyang river hydrological station,using the Baiyang river sediment transport modulus method,it can be known that the average suspended mass of the upper and lower reservoirs of the Fukang station is 0.138 million tons and 2.53 million tons.(6)According to the relationship between the water level and discharge of the flood discharge and drainage hole,it is known that in order to avoid floods with large sediment concentration,it is necessary to replenish water as soon as possible,and the highest normal operating water level when replenishing water is 1806m;when the water is replenished,the water level upstream of the sand barrier is controlled between 1803m and 1806m;the water level in front of the flood discharge dam in the past 5 years is 1803.7m.For safety,the highest hydration level in the non-flood period may be 1806m,which is pushed upwards as the As the backwater level of the interception dam reservoir.The length of the reservoir backwater is about 0.1km.(7)According to the sedimentation calculation of sediments,there is almost no sediment storage in the lower reservoir section(sediment storage dam to retaining dam),the upper reservoir has no need to consider sediment deposition due to the small amount of sediment into the reservoir.(8)the sedimentation of the reservoir in the reservoir area has a relatively small influence on the river potential.Smaller,the river’s ability to flood has not changed much. |
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