Safety construction of Jingjiang flood diversion area

Jingjiang flood diversion and storage area is first used in flood diversion and storage area, with short forecast period, flood depth of 7 ~ 10m and long duration (1954 flood lasts about 3 months), while the other three areas have relatively long forecast period, shallow floods and abundant transfer time. Therefore, the investment in safety construction of Jingjiang flood diversion project is basically based on Jingjiang flood diversion area. Since 1963, the state and local governments have invested about 260 million yuan, mainly including resettlement projects, transfer projects and communication projects.

Resettlement measures for residents mainly include: emigration, local resettlement, flood diversion and temporary flood avoidance.

When Jingjiang flood diversion project is completed, its design life is 20 ~ 40 years. With the population growth and social and economic development in this area, the requirements for flood control are getting higher and higher, and the construction of flood diversion safety has gradually developed from temporary emergency measures to comprehensive planning and phased implementation. Because the safety construction is mainly temporary emergency projects, the construction standard is low, and with the passage of time, the efficiency of the project is gradually reduced, so it can not be used normally. The main problems are: the safety of the safety zone, the difficulty in resettling the evacuated population and the small resettlement capacity of the safety zone, the evacuation and transfer of residents, the protection of property, the compensation for flood diversion and post-disaster reconstruction, and the control of flood diversion gates.

(1) flood diversion gate control. In Jingjiang flood diversion area, there are 27.8km long dams at 1 1 in addition to flood intake sluice and control sluice. After the flood diversion area is put into use, except for the 22-kilometer-long southern levee, the 208-kilometer cofferdam is flooded inside and outside, which will make it very difficult to transport personnel and equipment. Whether the design depth and width can be reached in time and the design flow can not be effectively controlled, the flood diversion gate construction control project is imminent. In view of the low application probability, the width of the wrapping head and the depth of the protective floor can be controlled. In terms of engineering sequence, Wuliangan spillway and Lalinzhou sluice have priority, while others are suspended.

(2) Transfer roads and bridges. According to the current flood diversion scheme, the forecast period is 48 hours. Considering various unfavorable factors in operation, it is actually only about 24 hours. At present, the current situation of road and bridge construction in this area cannot meet the needs of rapid transfer and evacuation.

(3) Population resettlement and safe areas. Jingjiang flood diversion area has a population of more than 540,000, of which more than 206,000 people have settled in the safety zone and Taiwan Province. During the flood diversion period, 6.5438+0.28 million people will be transferred to other places, and more than 207,000 people will be placed in safe areas. The population density of the safety zone will reach 6.5438+0.94 million people /km2, and more than 60 safety zones cannot live below the design flood level. As far as the safety zone is concerned, the dike has not reached the design flood control standard, and the platform inside the dike, the deep pond inside the dike, the sand foundation treatment and the slope protection of the dike body have not been completed. The existing scaffolding open space in the area is only 5.3km2, and nearly 30% of the area in the area cannot be utilized, and the deep pond near 1.33 m2 has not been treated. Except for Douhu levee, most of the safe areas have poor drainage, serious water accumulation, impassable roads and weak infrastructure. 80% of the resettlement houses in the area of nearly 200,000 m2 are dangerous buildings and uninhabitable, and some safe areas can no longer play the role of resettling residents.

According to the survey in 2000, there are 305,000 residents and 2.7 billion yuan of property in Jingjiang flood storage area. If corresponding measures are not taken, flood diversion will cause great losses to people's property in this area and bring great pressure to society.