Analysis On Sedimentation Of Wuqiangxi Reservoir And Impacts On Its Operation Based On ArcMAP

The sediment in the reservoir area deposits not only in the dead storage area but also in the active storage area,which changes the storage capacity and has an important impact on the operation and management of the reservoir.However,directly detecting and estimating the sedimentation and its distribution in the reservoir area is not only timeconsuming and laborious,but also expensive,and it is also difficult to guarantee the measurement accuracy.So far,for a long time,most reservoirs still use the storage capacity characteristics used in the design stage to operate and manage the reservoirs,and the research on sedimentation and its impacts on the management of reservoirs is rare.In fact,the advance of geographic information acquisition and its processing technology has provided the technical convenience for the analysis of sedimentation characteristics in the reservoir area.Based on Arc MAP geographic information processing technology and reservoir image data of Wuqiangxi Reservoir from 2005 to 2015,this paper estimates the sediment deposition and its changes,and updates the reservoir storage capacity curve,which is then used to analyze the impacts of sediment deposition on reservoir flood control and power generation scheduling.The main works and innovations of this paper are summarized as follows:(1)The siltation in the reservoir area is analyzed by introducing the Arc MAP technology,where the script files written with Python is run,and this provides a more efficient and time-saving way to verify the reservoir capacity curve.(2)Based on the analysis of the digital elevation image of Wuqiangxi Reservoir in the past ten years,the sediment distribution and the variation characteristics of the storage capacity curve in the reservoir area indicate that the sediment deposition in the Wuqiangxi reservoir area accounts for 2.73% of the total storage capacity,generally low in low elevations and small in high elevation zones.(3)Based on the storage capacity curves before and after the verification,the flood control operation is simulated using the 100th-year flood.The comparative analysis shows that the flood limiting level of Wuqiangxi should be lowered by 0.27(m)in order not to lower the designed flood control standard.(4)A medium and long-term hydropower reservoir operation problem is formulated and solved.And with three(dry,ordinary and wet)typical monthly runoffs of Wuqiangxi Reservoir,the influence of storage capacity change on the hydropower station's power generation is analyzed.The results show that based on annual average values for the dry,ordinary and wet scenarios,the annual power generation benefit reduced by 0.6 thousand and 0.44 thousand yuan caused by the reservoir sedimentation to 2005 and 2015 compared to the original design reservoir.