Research On The Method Of Dredging Vessels Selection Based On Aquatic Organisms Biomass Loss

With the rapid development of water transport in our country, coastal engineering construction such as port and waterway construction is more and more frequent. As a necessary activity to guarantee the construction of port and waterway, the volume of dredging engineering is increasing in recent years. However, marine environmental pollution problems caused by dredger’s dredging operation are increasingly prominent. The suspended substance (SS), oil, waste water, solid waste and so on produced in construction process directly affect the water environment and marine ecological environment in the surrounding sea. and threaten the growth, habitat and survival of all kinds of aquatic organisms. This will result in damage to marine biological resources and degeneration of ecological environment.With regard to the effect of SS on marine environment, this paper studies the relationship between type and dredging efficiency of dredgers and SS concentration increment in the operation center, and proposes an aquatic organism biomass loss calculation method. Then dredger selection evaluation model based on aquatic organism biomass loss is build. A dredging engineering is taken as an example to describe the application of the dredger selection method.When building the selection evaluation model, this paper references available research on the relation between SS and aquatic organism biomass loss, and proposes the calculation method of aquatic organism biomass loss. After learning about dredging construction characteristics and dredging specialty of all kinds of dredger in detail, the fuzzy comprehensive evaluation method based on norm grey relational grade is applied to dredger selection, in which the ecological and technical factors affecting dredger selection is considered. In the example, a two-dimensional model of transport and diffusion of SS is established, and diffusion range of SS caused by dredging operation of bucket dredger, cutter suction dredger and drag suction dredger is calculated. Then, through applying this research method, this paper analyzes the variation relationship of plankton and fish biomass loss caused by these dredgers’ dredging operation under the different dredging efficiency. Based on the above research, the fuzzy comprehensive evaluation and priority order of six alternative dredgers under the background of this project is given, to provide a scientific way for the application of dredger selection evaluation model.The research of dredger selection evaluation model based on aquatic organism biomass loss put forward a quantitative method to analysis the effect of dredging engineering on aquatic organism biomass and dredger selection. This method can provide scientific basis for selecting dredging vessel, protecting the marine environment and establishing ecological port.