The Influence On Marine Ecologic Environment By Dredging And Protection Countermeasures

With the economic globalization nowadays, maritime traffic is very important for economic development and international trade. Generally speaking, few littoral ports and sea-routes are in the natural deep-water area, so the water depth must be maintained by dredging. Confined to the dredging machines and technology, heave sand concentration will be caused in the construction area. Affected by the dynamic factor such as tide, the heave concentration water will diffuse, and will result in the increase of adjacent seawater's turbidity. Meanwhile, poisonous and harmful substances included in the sand will reduce the seawater quality. All of these will pollute the marine ecology. Along with the fast development of littoral economy and nautical transport in our country, the number of the construction and maintenance of the port,sea-route,oceanic and coastal projects increases rapidly. If without control, the marine ecology will be destroyed to a certain degree. Now people have realized the limitation of the marine's efficacy, if only demand without conservation, the ocean could supply fewer resources to human, till the resources exhausted. So protecting the marine ecology environment against pollution is beneficial to our descendants, and it is human's historical responsibility. It is necessary to control the pollution of dredging suspended substance strictly, and it is the trend of the times.The study of the paper includes two parts: forecast of environmental pollution and countermeasures of pollution protection:(1) Correct pollution infection forest can provide gist to pollution protection and environmental management, it is the precondition to control the construction pollution effectively. Numerical model is effective means of forest. Comparing with measure at site, numerical model can save a great deal of manpower,material resources and financial resources. According to the characteristics of dredging construction, this paper selects a typical project, analyzes the technical characteristics of dredging and overflowing which are main technics. General work conditions of dredging and overflowing are designed, tidal current field and consistence field of suspend contamination near the project are simulated with 2-D mathematical model. According to the environment request of the construction sea area, on the base of computing environmental influence of using different types of dredgers and setting different overflow gates, satisfying construction technics and reasonable overflow place are brought forward.