Flood control standard of Xidayang Reservoir

Hello! Geographical location Xidayang Reservoir is located at the downstream of Xidayang Village, Tangxian County, at the exit of Tanghe River in Daqing River system 1km. The reservoir controls a watershed area of 4420 km ㎡, with a total storage capacity of165438+37 million m3. It is a large-scale (1) reservoir which mainly focuses on flood control and gives consideration to the comprehensive utilization of urban water supply, irrigation and power generation. The engineering grade is Grade I. The Xidayang Reservoir is designed by the Design Institute of Hebei Provincial Water Resources Department. 1958, 1960. After 1963 flood, the experience shows that the flood control standard of the reservoir is too low to meet the flood control requirements. 1In April, 1970, Baoding District Revolutionary Committee began to continue the construction of Xiyang Reservoir, and the project was completed in June, 1972. After the continuation of the project, the dam protection standard has been raised to 654.38+10,000-year flood. However, the actual flood control standard of the reservoir is only once in 500 years, which is far below the standard required by the code. In addition, the downstream dam slope of the main dam is steep, which can not meet the requirements of the code under normal use and earthquake conditions. There are some problems in normal spillway, such as insufficient strength of embedded parts of gate and some components of gate. Therefore, 1992, according to the once-in-a-lifetime standard in 2000, the emergency reinforcement project focusing on the construction of emergency spillway and dam reinforcement was completed at the end of April 1994. On June 29th, 20001year, the dam safety appraisal of Xidayang Reservoir was carried out. The appraisal results show that there are some problems in the dam, such as low flood control and dam protection standards, and unsatisfactory anti-sliding stability of downstream dam slopes. According to the dam safety classification standard, the dam of Xidayang Reservoir is determined as the third-class dam. At present, the reservoir reinforcement project will be implemented soon. After reinforcement, the flood control standard of the reservoir will reach the design flood with a return period of 500 years and the check flood with a return period of 10000. 4. At present, the reservoir flood control standard is less than once in 2000. After more than 30 years of application, it has played a great role in flood control, irrigation, water supply and power generation. Major floods such as 1963, 1964, 1979 and 1994 were intercepted, and the reservoir water in the 1963 catastrophic flood began to rise rapidly on August 7, because the reservoir water level was far below the flood limit. At 20: 30 on August 8th, it rose to140.1m (dagu elevation, dagu elevation-1. 15 1=85 national elevation datum, the same below), with the maximum storage capacity of 7944. In addition, the West Ocean Reservoir also undertakes the task of supplying water for downstream cities, industry and agriculture. Under the current situation, it will supply 50 million m3 of water to Baoding's urban industry and life, and it is planned to supply 94.6 million m3 of water to 500,000 mu of farmland in Baoding and Tanghe Irrigation District. 1.500 million m3, and it is planned to supply 32 million m3 of water to Dingqu Power Plant. Technical index 1. Characteristics of the basin: Xidayang Reservoir is located at the downstream of Xidayang Village at the exit of Tanghe River in Tangxian County 1km, with a controlled basin area of 4420 km ㎡, accounting for 88.7% of the Tanghe River basin area. The total length of rivers in Tanghe River Basin is 273 km, of which mountain stream 182km, and the river slope is steep, and the longitudinal slope is generally 0.2% ~ 0.5%. The average rainfall of the basin for many years is 5 1 1mm, the average evaporation for many years is about 15 1 mm, and the historical maximum inflow peak flow is 7940 m3/s, which occurred on August 8th, 1963, and the historical maximum flood level is140. The main dam is a homogeneous earth dam, the upstream dam is provided with a masonry breakwater, the downstream dam foundation is covered with gravel, the upstream dam is provided with impervious blanket, the downstream dam is provided with cushion drainage, and the reverse filter ditch is provided for decompression. 3. Spillway: The normal spillway of Xidayang Reservoir is located at the east foot of Heifeng Mountain at the right end of the main dam. During the initial construction of 1958 to 1960 reservoir, the normal spillway was a wide-topped weir without gate control, and the reservoir project was extended from 1970 to 1973, and the normal spillway weir was transformed into a "Ke-Ao" type practical weir. On both sides of the lock chamber are open practical weirs. Spillway project consists of four parts: inlet diversion open channel, sluice chamber section, chute contraction section and chute narrow section. The emergency spillway is located at the southern end of the auxiliary dam on the slope. The structure type is fixed portal frame, and the dam self-destructs at the upper part. 4. Exit tunnel: Exit tunnel includes flood discharge tunnel and water conveyance tunnel. The spillway tunnel is located on the left side of the main dam. The tunnel is a circular pressure tunnel, and the water conveyance tunnel is located on the left bank of the main dam. Cross Liuqiaopo mountain bag and irrigation canal, and enter Tanghe River. The tunnel is a circular pressure tunnel. 5. Hydropower Station: The power station is located on the left bank of the river behind the main dam and is equipped with 4 units. 6. Reservoir inundation treatment: the land acquisition elevation of Xidayang Reservoir is 145m, the inundated farmland is 42,700 mu, the resettlement elevation is 143.95m, and the immigrant population is 32 199. 7. Irrigation and water supply: Xidayang Reservoir undertakes more water supply users downstream. Under the current situation, 50 million m3 of industrial and domestic water is provided to Baoding, and1500,000 m3 of water is provided to 500,000 mu of Tanghe irrigation area. It is planned to supply 94.6 million cubic meters to Baoding City and 32 million cubic meters to Dingqu Power Plant. State indicators of reservoir characteristic value: total storage capacity11370,000 m3, flood regulation storage capacity 758 million m3, beneficial storage capacity 5150,000 m3, dead storage capacity 79.9 million m3, dead water level 120.0m, and start-up water level134. The normal water level is 65,444 ... After reinforcement, the indicators are: total storage capacity is 65.438+258 million m3, flood control capacity is 879 million m3, Xingli storage capacity is 56.5438+500 million m3, dead storage capacity is 79.9 million m3, dead water level 1.20 m, starting water level 134.5 m,. Flood control standards When the Xidayang Reservoir was first built, the design flood control standards were 100 once-in-a-year flood design and 1000 once-in-a-year flood check. After 1963 flood, it was found that the flood control standard was low, which occurred once every 300 years, so 1970 continued construction, and the design standard was still 100 once, and 1000 once. After the review of "three inspections and three determinations", the reservoir project can only resist the flood once in 500 years. After the reinforcement of 1992 ~ 1994, the existing flood control standards are designed according to the 500-year return flood and checked according to the 2000 return flood. After the reservoir is reinforced, the flood control standard is 500-year return flood design, and 10000 return flood check. Downstream protection object and scope 1, towns and important industrial and mining areas: 5 counties and Huabei Oilfield; 2. Population: 3.4 million; 3. Cultivated land area: 4.6 million mu; 4. Railways: Beijing-Guangzhou Railway and Beijing-Kowloon Railway; 5. Highway: Beijing-Shenzhen Expressway, Jinbao Expressway and National Highway 107. Since the establishment of Xidayang Reservoir, the historical flood dispatching has never encountered a major flood except 1963, and the operation in flood season is basically in accordance with the operation mode approved by the superior. 1979 inflow peak is 2960m3/s, the maximum outflow peak is 360m3/s, the flood peak is reduced by 88.0%, the flood detention capacity is1320,000m3, and the highest water level of the reservoir is 138.37m, 1996 inflow peak/kloc-0. The water level of the reservoir began to rise rapidly, reaching 140.9m at 20: 30 on August 8, with a maximum storage capacity of 7940 m3/s. At the same time, the spillway and spillway tunnel are used for flood discharge, with a maximum discharge capacity of 1670m3.