(1) The project has little impact on the surrounding environment.
According to the inspection and expert review by South Academy of Sciences and Institute of Natural Sciences, it is considered that the reclamation project has no obvious influence on flood control and drainage in Oujiang Estuary. It is beneficial to the stability of the middle channel of the main channel outside the port and the increase of the depth of the sandbar; It is beneficial to improve the berthing stability conditions of Qili deepwater port area; Whether the lower end of the north dike of Lingni is blocked (that is, around or "leaving a mouth") has no obvious adverse effect on the deep water resources of Zhuangyuan 'ao; The reclamation project has also eliminated the sand blowing and transporting in the southeast of Wenzhou Shoal, which has played a positive role in maintaining the water depth in the port area. It has no influence on the tidal current structure of the whole Oujiang estuary.
In June 2002, Zhejiang Ocean and Fisheries Bureau organized a review of the Demonstration Report on the Use of Sea Areas in Wenzhou Shoal Phase I Project, and concluded that the use of sea areas involved in Wenzhou Shoal Project met the requirements of large-scale marine functional zoning in Zhejiang Province and Wenzhou City. According to the results of special research, the project has little or no impact on the port channel, the development of biological resources and the marine ecological environment in the surrounding waters.
In the process of project implementation, we insist on the combination of short-term and medium-term, the combination of development management and resource protection, and the combination of reclamation and siltation promotion, so that resources can be updated and restored. At the same time, we should attach great importance to the impact on the surrounding natural environment, adhere to the concept of paying equal attention to development and protection, prevent development from exceeding the environmental capacity and the carrying capacity of resources themselves, make overall planning and comprehensive utilization, and strive to achieve the unity and coordination of social, economic and ecological benefits.
(2) The engineering technology is feasible
Wenzhou Shoal is a typical marine muddy soft foundation and strong tidal area in the East China Sea. The key of engineering design lies in soft foundation treatment and dam structure.
Shoal silt has the characteristics of high compressibility, high water content, high sensitivity and low strength, and the difficulty of foundation treatment is rare in China. At present, there are many methods for soft foundation treatment, such as preloading with drainage board, silt squeezing by blasting, pile foundation, etc. Among them, the most effective solution is to use the combination of plastic drainage board, geotextile and compaction layer to strengthen foundation treatment. By controlling the loading rate of riprap, the bearing strength of foundation soil can be improved and the construction progress can be accelerated. At the same time, the slope protection of the dam adopts the structure of pouring concrete blocks, which effectively protects the shape of the dam. Therefore, most coastal reclamation projects in Zhejiang adopt this technology.
In order to verify the reliability and applicability of the sandbar dam structure, a 1800-meter test dike was built in advance on the side of Niyu Island, and management experience was explored and accumulated in the design and construction. The test dike was successfully constructed and completed in February 2003. After the test of typhoon "Yunna" in 2004, the test dike still stands tall on Wenzhou Shoal. Practice has proved that the foundation treatment and embankment structure of the test embankment are reliable and the investment cost is low, which is basically adopted in Wenzhou Shoal Reclamation Project.
(3) The economic benefits of the project are remarkable.
After the completion of the shoal project, the economic benefits are very considerable. First, after the completion of the first phase of reclamation, the enclosed area is 23,700 mu. According to the current land acquisition cost of Wenzhou, which is 6.5438+0.3 million yuan per mu, the land value of the first-phase enclosed area will reach 36.5438+0 billion yuan. The land produced by land reclamation will greatly alleviate the land bottleneck restriction of Wenzhou's economic and social development, and its indirect benefits will be huge through development and utilization; Second, the transportation cost savings are obvious. After the first phase of the project was completed and opened to traffic, it created favorable conditions for collecting and distributing goods in Dongtou County, especially in Zhuangyuan 'ao deepwater port area, and greatly reduced the short-distance transportation cost and transit cost of goods. Third, the income induced by tourism is considerable. Statistics show that the tourist flow in Dongtou County has increased by 10% every year in recent years. After the completion of the Lingni seawall, it is estimated that the tourism industry in Dongtou County will attract 60,000 people every year. After the completion of the National Ocean Park in Dongtou, the average annual growth rate of tourism will not be less than 10%, and the direct income from tourism will be considerable.