| Water transport enjoys a long history coz it boasts a number of advantages such as large capacity,low cost,environmental protection,etc.Channel is the area which guarantees safe navigation,since normally,streams alone can not meet sailing requirements,thus engineering measures such as navigation projects have to be adopted.Ever since the founding of the new China,navigation channel constructions have enjoyed tremendous development.Improvements on water transport efficiency and flood control capacity have exerted positive impacts on stability of ecological environment outside river wall.However,channel regulation constructions also have negative effects on environment,including destruction and reduction on habitat of flora and fauna,sound pollution,etc,which should be given high attention.The ecological environmental impact evaluation research of navigation channel regulation project in China is still in the phase of exploring,which is not mature enough and need to be improved in evaluation theory,methods and systems.With study of beneficial experience on ecological environment impact assessment about navigation channel regulation project at home and abroad,the article introduce theoretical basis,technical methods of waterway regulation project separately use the "Environmental Impact Assessment Technical Guidelines For The Ecological Impact(HJ 19-2011)" as the standard.On the bases,we take the Hu guang to Luo huzhou reach training works as an example and evaluate the terrestrial and aquatic ecosystem of the region around the characteristics of the waterway regulation project ecological impact evaluation,then come to the conclution by using a variety of methods,finally put forward targeted measures to reduce and avoid its negative effects on the ecological environment.In the aspect of terrestrial ecosystems:The impact of high beach guardian works on terrestrial plants is mainly caused by land slope of slope excavation and backfill slope,beach protection zone and the roots of beach protection project occupied land led to the destruction of vegetation,and the area above are permanent.Reinforcement project of revetment works using underwater riprap or throwing permeable framework forms,it does not occupy land and therefore does not influence terrestrial plants.Although temporary construction jobs occupied land with damaged vegetation,it accounts for a small proportion of total project area,ecological slope protection and vegetation restoration measures can gradually reduce the negative impact of temporary covers after the end of construction.Paved beach protection with soft mattress,revetment excavation and cutting the slope in training works damage and narrow the wildlife habitat,block some of its active channels.Human activities such as ripraping revetment works,dumping permeable framework generate noise impacts on animals,but animals will find the nearest place to instead of they are habitats,and the construction time is limited,the noise impact will not be long-lasting.In the period of operation,the number of ships in the assessable area is greatly increased,so animals will be relocated to the habitats which less affected by the ship's noise and light.On the other hand,the operation of the project will improve flood control capacity and have good ecological effects on stabilizing the terrestrial plant and animal habitats,it is also play a positive role in maintaining regional ecological diversity.In the aspect of aquatic ecology:Sinking mattress,ripraping slope compensation of restoration project and ripraping revetment works,dumping pervious frame of bank protection works will stir the water,resulting in suspended solids,inhibiting the growth of phytoplankton,so zooplankton and fish are effected.Layout of construction will directly ballast benthic sediment bed,stones and permeable framework taken into water in the engineering of bank protection will also occupy benthic habitats,resulting in the loss of the biomass.Buildings occupied by the river will also reduce the number of fish migration or migration of the channel,their habitats,breeding migration and migratory activities have some impact.The project without blasting sudden injury construction technology,ripraping and sinking the type of D consructions derectly impact fish which produces a noise influence on fish in the project area and its adjacent waters downstream,and other aquatic animals are driven.Implementation of the project will destroy the spawning grounds spawning conditions for a period of time,fish breeding of production of heavy,sticky eggs also have some effect.Overall,water disturbance,construction noise impact on the aquatic ecosystem is relatively short during the construction period of navigation channel regulation projects,and it will disappear with the completion.But engineering ballast riverbed cause the habitats and migration channels are occupied,local river environment,water flow patterns,flow rate,meandering of the river morphology are also changed,all of these will have effects on aquatic ecosystems which are most important and long-term.So,when we achieve the aim of improving fairway conditions we should also take effective measures to reduce its impact.Ecological environmental impact assessment of the navigation channel regulation project and other construction projects have something in common,but it also has its own professional characteristic.The professional characteristics of navigation channel regulation project environmental impact assessment mainly displays in the aspects of evaluation basis and standards,forecasts and analysis combined with engineering,corresponding environmental protection countermeasures and measuresThe theories and methods for navigation channel regulation project of eco-environmental impact assessment is supplemented,summarized and improved in this paper for the first time,and the actual scientific case is cited to predict and evaluate the environmental impact of channel regulation.Hope these can offer reference for ecological environment assessment of other waterway regulation projects. |
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