The Bohai Sea is an important inland sea on the mainland, with an area of about 80,000 square kilometers and an average water depth of 18 meters, rich in fishery, oil and natural gas resources.
In addition, now that nuclear sewage is approaching the Bohai Sea step by step, some people have asked whether it is possible to build a super dam at the mouth of the Bohai Sea and turn the Bohai Sea into an inland lake in China.
Is it really feasible to build a Bohai dam, and can it stop the contamination of nuclear wastewater?
Advantages of building a dam in the Bohai Sea
The Bohai Sea has a flat seabed and abundant bait, which is a large-scale marine aquaculture base in China, rich in shrimp and yellow croaker. There are many salt pans along the coast, and the Changlu salt field on the west bank is the most famous, with good natural geographical conditions.
The port has a high distribution density, many large ports and energy export ports, and is an important sea passage for foreign trade in northern China, with a coastline of 5,800 kilometers and more than 100 ports that have been built and should be built.
The Bohai Economic Circle, which is built around the Bohai Sea, includes a land area of 521,000 square kilometers and a population of 242 million, consisting of 3 provinces of Hebei, Shandong, Liaoning, Beijing and Tianjin, and 13 cities around the Bohai Sea.
As the two wings of the Bohai Economic Circle, Shandong Province's GDP in 2023 will be 9.2 trillion yuan, with an average annual growth rate of more than 6% in the past three years, with a population of more than 100 million, and the GDP of Liaoning Province will be 3 trillion yuan, an increase of 5.3% over the previous year, with a population of more than 42 million, and the regional development imbalance is obvious.
If a dam can be built in Bohai Bay, the Shandong Peninsula and the Liaoning Peninsula will be directly connected, from Liaoning Lushun to Shandong Penglai, the journey will be shortened from more than 1,400 kilometers to more than 100 kilometers, and the previous 6 and a half hours will become 40 minutes, and it used to take 12 hours to drive, but now it only takes 1-2 hours.
Coal, iron ore, molybdenum ore and magnesite from the Liaodong Peninsula can quickly reach the Shandong Peninsula, and the oil, iron ore, bauxite and potash of the Shandong Peninsula can also be transported to Liaodong quickly.
Once the dam is completed, the sea water in the Bohai Sea will be gradually desalined and will become the largest freshwater lake in the mainland, and although the implementation of the South-to-North Water Diversion Project has alleviated the problem of water shortage in the north to a certain extent, it is still a symptom rather than a root cause, and the implementation of the Bohai Sea freshwater lake plan will completely solve the problem of water use in the north.
In addition, the westward diversion of seawater is no longer a utopia, the Bohai Sea is only more than 400 kilometers away from the Hunshandak Sandy Land of the Inner Mongolia Autonomous Region, the introduction of Bohai seawater, the formation of artificial lakes, the expansion of wetland area, through the natural evaporation of seawater, provide humid climate conditions in the northwest region, increase rainfall, eradicate sandstorms, drive the development of agriculture, animal husbandry and fishery along the river, and increase economic income.
Further to the distance, flowing through the north of Yanshan and Yinshan, out of the Wolf Mountain to the west into Xinjiang, introduced into Turpan, Hami Basin, Lop Nur Desert, not only to improve the local ecological environment, but also to completely change the poor ecological environment of the entire northwest region, and fresh water will not affect the inland soil structure, will not cause ecological problems, the Bohai Sea water purification cycle will be shortened, the water quality will be changed for the better, which is conducive to the local environment.
Comprehensive consideration of the Bohai dam construction project
The Shandong Peninsula is dominated by plains and hills, and the Liaodong Peninsula is dominated by steep mountains, and a dam is built between the Liaodong and Shandong Peninsula to completely enclose the Bohai Sea, which needs to be repaired from Penglai in Yantai to Dalian, Liaoning, with a total length of more than 100 kilometers.
In contrast, the Three Gorges Dam is 2.3 kilometers long, took 36 years, and cost 135.266 billion yuan, and the Hong Kong-Zhuhai-Macao Bridge is 55 kilometers long, taking 10 years, with a total investment of 126.9 billion yuan.
The Bohai Sea is under the "wrapping" of two peninsulas, the evaporation of seawater is low, and now the greenhouse effect has caused the global sea level to rise slowly, if the Bohai Sea is enclosed, the Bohai Sea recharge remains unchanged, and the circulation of surrounding seawater slows down, and its sea level will rise year by year, inundating the coastal land, and the gains outweigh the losses.
The self-purification capacity of the Bohai Sea has been weakened, and the exchange of its own water bodies is extremely slow, and the current cycle of the entire Bohai Sea seawater cycle takes about 40-200 years, and the already serious seawater pollution problem along the coast will be further amplified. In addition, the destruction of its unique marine ecosystem will affect marine biodiversity and cause a series of ecological problems.
Changes in the environment of the Bohai Sea will also lead to a decline in the number of aquatic organisms such as fish, affecting the aquaculture industry in the Bohai Sea, and the continuous desalination of seawater will also affect the development of the salt industry.
In addition, the Bohai freshwater lake plan could also spark geopolitical and international controversy. The Bohai Sea is one of the most important waterways between China and South Korea, Japan and other countries, and its transformation into a freshwater lake will have a significant impact on the shipping and port economies of other countries.
Therefore, the construction of the Bohai Dam still needs to be treated with caution, and it is currently only a private and spontaneous project, and there is no official plan.
Will damming the Bohai Sea really turn the Bohai Sea into a freshwater lake?
In the last century, the Dutch built a 90-metre-wide barrage 7 metres above sea level to completely isolate the Zuiderzee from the open sea, and after decades of change, the Zuiderzee became the largest freshwater lake in the Netherlands.
However, the area of IJssel Lake is only 1,100 square kilometers, while the Bohai Sea has nearly 80,000 square kilometers, and the volume of seawater in the Bohai Sea is about 1.6 trillion cubic meters, the total annual runoff is about 80 billion cubic meters, and the annual evaporation is about 30 billion cubic meters.
Even if we do not consider the influence of water use in the middle and lower reaches of the river, evaporation loss, and drought and interruption in recent years, the annual inflow is about 50 billion cubic meters, and the salinity in the Bohai Sea is 30‰.
According to the general standard of freshwater lake salinity less than 0.3‰, the salt content of seawater remains unchanged, and the dilution water consumption is 160 trillion cubic meters, even taking into account the amount of precipitation, it will take at least thousands of years to complete the transformation of the Bohai Sea into a freshwater lake.
Japan's Fukushima nuclear sewage is expected to arrive in Zhejiang on April 20, 2024, Shanghai on April 25, and spread all the way north to Shandong, Liaoning and other coastal provinces.
Even if it is built, the seawater will evaporate to form rainfall, and pollution in the Bohai Sea will still be inevitable, and even the situation will be made worse because the seawater cannot flow, affecting the self-purification of the seawater.
epilogue
The construction of a dam in the Bohai Sea can not only promote the development of the Bohai Rim Economic Belt and completely solve the dilemma of water shortage in the north, but it will also cause changes in the coastal environment and cause ecological problems, in addition to geopolitical and international disputes, and it will take thousands of years for seawater to become a freshwater lake, and it is even more impractical to resist nuclear wastewater, so we should take a more cautious attitude towards whether the project is implemented.
Bibliography:
NetEase News.Is the feasibility of the Bohai freshwater lake plan beneficial or wishful thinking?
In order to block nuclear sewage, the Bohai Sea dam was sealed, is this reliable?