The total area of the Danjiangkou Reservoir is 1,022 square kilometers, the total area of the Three Gorges Reservoir is 1,084 square kilometers, the total area of the Xiaolangdi Reservoir is 278 square kilometers, and the water surface area of the Sanmenxia Hydropower Station is 410 square kilometers. The capacity of the three reservoirs is 80 billion cubic meters. The four power stations cover an area of about 2,800 square kilometers, and their direct economic value is very low except for flood control and water conservancy.
Make full use of the reservoir capacity and allocate 100 billion tons of water resources to the North China Plain?
In the past three years, the flow of the Yellow River into the sea has exceeded 30 billion tons, and the annual flood discharge of the Danjiang Estuary is 40 billion. However, the North China Plain is severely short of water.
If we can store water dynamically in the three reservoirs of Danjiangkou, Sanmenxia and Xiaolangdi. In the non-flood season, water resources are discharged according to the downstream water consumption, and the storage capacity is poured out once a year (not completely emptyed). Here's how:
1): The Danjiangkou Reservoir is divided into two, with an investment of 25 billion yuan, 2 tunnels of 35 kilometers will be built, and two Hanjiang dams will be built using the excavated muck. As shown in the figure below
The two dams split the original Danjiangkou Reservoir, which can operate at a height of 165 meters to ensure that the head of water is sufficient, and the Hanjiang Reservoir can be used as a flood storage reservoir. It has a storage capacity of 14 billion cubic meters. In the non-flood season, pumped water storage is used to pump the Hanjiang Reservoir to the Danjiang Reservoir, and the Guishan Reservoir is used to generate power and recover pumped energy. Its pumping efficiency is 50%.
How to recover the cost of tunnel construction?
The 40 billion tons of water from the Danjiangkou reservoir can be fully diverted to the Yellow River basin. 0.1 yuan per ton of water, the cost can be recovered in 8 years. After the cost is recovered, the water transfer fee will be exempted. If the cost of tunnel construction is doubled to 50 billion, the cost can still be recovered within 15 years.
After the Danjiangkou Reservoir has enough water, the second step can be carried out, as follows:
2): The middle route of the South-to-North Water Diversion Project will be expanded, with an annual water diversion of at least 40 billion tons. Invest 100 billion.
The middle line of the South-to-North Water Diversion Project is expanded, and the maximum adjustable water volume is 60 billion cubic meters per year under the condition that the water head is sufficient, and the Danjiangkou Reservoir to Nanyang is transferred according to the existing South-to-North Water Diversion Line, and the tunnel is used to transfer water from Nanyang to Lushan. From the Guishan Reservoir to the Yellow River, an artesian nullah can be used to widen the existing irrigation channels, eliminating a large amount of land acquisition costs.
2): From the Yellow River Black Mountain Gorge to Juyan Sea, the weak water enters Lop Nur, and the weak water has 10 billion cubic meters and an investment of 80 billion yuan in the year
There is no longer a shortage of water in the lower reaches of the Yellow River and the North China Plain, and most of the water resources can be intercepted in the Heishan Gorge in the upper reaches of the Yellow River, and there are Qingtu Lake and Juyanhai. When there is a shortage of water downstream, a large amount of water can be released in dry years. More than 300 billion cubic meters of water are stored.
Divert water to Qingtu Lake route
After the restoration of Juyanhai and Qingtu Lake, more than 10 billion tons of water will flow into Lop Nur every year, which is equivalent to one-third of the Tarim River.
3) The Tongtian River was diverted to the Qaidam Basin, and after the ecological restoration in the basin, it flowed into Xinjiang. 130~50 billion tons of water from the Jinsha River are pumped and stored and flowed into the Taklamakan Desert. Every year, 60 billion tons of water are transferred from the weak water and Jinsha River to the desert of Xinjiang. Enough to develop all the deserts.
The direction of the tunnel from the Tongtian River to the Qaidam Basin is to take the route with the minimum buried depth.
The buried depth and the diameter of the tunnel are the factors that have the greatest impact on the construction cost, and the maximum buried depth of the project is 1182 meters, and the tunnel section exceeding 600 meters accounts for 45%. Choosing a burial depth of less than 150 meters in the water transfer design is expected to reduce the cost by half. The total investment of the project is 600 billion yuan, the total length of the tunnel is 193 kilometers, the diameter of the tunnel is 10 meters, and the maximum water diversion is 6.8 billion cubic meters. The cost per kilometer is 300 million. The charge for tons of water is 1 yuan.
Rebuild a Sichuan Basin, a real new Tianfu, with a new design buried depth of less than 150 meters, 200 kilometers, a diameter of 15 meters, and a water diversion of 13 billion. The investment is less than 50 billion. The fee for tons of water is 0.25 yuan, which will be charged for 25 years, and it will be free of charge after recovering the cost.
The diameter of the water diversion tunnel is usually 10~20 meters in diameter, and the maximum adjustable water volume of 10 meters is more than 6.8 billion cubic meters according to the conditions of diversion and replenishment of Han water, and the diameter of 20 meters can exceed 28 billion cubic meters. For details of the specific construction process, please refer to the article of the WeChat public account of the Great Power Science and Technology Academy.
In the whole line buried depth of no more than 120 meters of water diversion tunnel, it is possible to achieve a diameter of 20 meters of water diversion tunnel.
Another measure to achieve low costs for water diversion tunnels is to improve excavation techniques. Achieve zero muck transportation.
After the water is opened, the water flow is used to wash away the muck in the tunnel. Technological innovation to realize low-cost water diversion tunnel excavation. With a two-meter diameter excavator, a tunnel with a diameter of 10~20 meters can be dug to achieve zero muck transportation.