Sediment Plumes Arising from Dredging Operations Are Perceived by Many Stakeholders In

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Sediment Plumes Arising from Dredging Operations Are Perceived by Many Stakeholders In

C:\windows\TEMP\dpcarticle2.doc though considerable progress has been made on the mathematical modelling of sediment plumes and plumes sediment of modelling mathematical the on made been has progress considerable though Al monitoring. and investigation require that effects environmental cause to environment coastal and marine the in stakeholders many by perceived are operations dredging from arising plumes Sediment Background DREDGINGSCOPINGOF ARISING SEDIMENT ASSESSMENT PLUMES FROM THE Stuart Meakins ChallinorSteve Authors L: AE/ / AE0911 DPCarticle2.doc periencefrom HongKongand Europe,States. the United ex Steering and expertise brought who subject the in experts The acknowledged and funders of up made was group project. the guide and advise to Group Steering international an appointed also CIRIA and the beneficial disposaluse of and dredged materialwere the project.beyond the scope of waterways inland of dredging the from arising plumes Sediment areas. estuarine plumes and coastal marine, sediment in of dredging maintenance assessment and capital the and aggregate marine on both for report operations dredging from scoping arising a producing with tasked was team research The Science). Aquaculture and Fisheries Environment, for Centre (the CEFAS and Wallingford HR Environment, Duvivier Posford comprising tender competitive by team research a appointed CIRIA Sea Directorate,theNetherlands tractors (FDC), MAFF and Worksof the MinistryTransport,Public Water NorthManagement and Marine ProducersAggregate EnglishAssociation (BMAPA),Federationof DredgingNature, Con Funding forprojectthewasfrom Waste DETR obtained and Division PlanningMinerals , British       addressing following theobjectives: by issues these considered project The dredging. from arising plumes sediment of effects the of ment assess the to approach structured a for need the found also CIRIA dredging. of effects plume the of assessment the improve to order in regulators and industry dredging the by use concurrent for gether to bringing needed and disparate was plumes sediment on knowledge current that view the reflected need This stakeholders. other and regulators industry, dredging the with consultation the through project for need the identified CIRIA effects. their and operations sedi dredging of during nature arising the plumes ment on knowledge of state current the review to 600 (RP) Project Research tablished es Association) Information and Research Industry Construction (the CIRIA background, this With on-site by (supported environmentaltheeffects sediment of plumes. techniques optical of and knowledge of lack a and acoustic techniques predictive verified of lack a using is there calibration), and sampling plumes of measurement field the on dredging plumes. with associated effects environmental the of assessment the for framework comprehensive a velop de and techniques, modelling review guidance, produce to required work further recommend to toproduce a report comprehensiveon current understanding gapstoidentifyincurrent knowledge and them to address research initiatives relevancetoreviewthe ofrelating legislation plumesto sediment toexamine current environmentaltheimpacts knowledge plumes on sediment arising from from marine aggregate and dredgingand capital maintenance arising plumes sediment on overseas) and UK the (in studies case relevant and research review to CIRIA(Construction Research Information Industry Association) and PosfordDuvivier Environment ------C:\windows\TEMP\dpcarticle2.doc Since aggregate, capital and maintenance dredging entail the use of different dredging methods, in the in methods, differences exhibit they dredging sediment, of types different different of dredging the of and environments different use the entail dredging maintenance and capital aggregate, Since place. takes dredging the which in conditions hydrodynamic the and material, the the operation, plumes: dredging sediment of generation the on influences primary three are There operation. dredging a during occur that otherwise, and deliberate losses, the essentially are plumes sediment of sources The the hydrodynamic environment the strength and of (mainly the current). direction by extent greater a to controlled is movement plume phase, passive the In is water. it the how into placed and material the of concentration and nature the by determined mainly is behaviour plume phase(where, moves broadly, toother the plume phase,due it).acting influences In upon the dynamic passive the and volition) own its under moves plume the (where phase dynamic the phases; or types, two are there which of plume, sediment a forming column, water the into sediment releases Dredging Sources of Sediment Plumes L: AE/ / AE0911 DPCarticle2.doc   sediment of extent the mitigating for plumes,focusing two on fundamental of areasmitigation: options with concerned work recent reviews also project The of set how identifies any and dynamic plumesand sediment affectwatercolumn passivethe and ways.seabed in different dredgers, and in types plume arise types, sediment could environmental projects, relates dredging impact different project to The effects any predictable. almost are reason, impacts potential Within most hydrodynamic however, of circumstances; variability space. the and and time habitats across and sediments conditions of nature site-specific the of because derive to difficult are impact particular a and operation dredging single a between relationships Direct ecology, marine quality, water on fisheries and shellfisheries. focussing by effects), cumulative (including plumes sediment of a with is effects associated environmental resource the on knowledge effects available environmental reviews project The environmental its be. not need and the plumes sediment seabed dredging, the of of consequence loss unavoidable the and While fundamental seabed. of loss direct associated the those to with secondary often are plumes sediment with associated effects environmental The Effects Environment theMarineMitigating Effects Environmental on and mud fluid models; flow models;holistic models;passive models;and processmodels. waterqualityplume plume dynamic models; process dredging categories: broad following the in 600 RP of by reviewed is state Modelling detail. the in 600 RP and by addressed is identified processes these are regarding knowledge plumes sediment of dispersion and advection the physical affecting main The processes environment. aquatic the on impact may they how understanding to view a with plumes sediment of modelling and dynamics the on research available the reviews project CIRIA The ProcessesPlume Modellingand is data limited and potentially unreliable. reported the of applicability general the that warns specifically 600 RP techniques. dredging various the for given are obtained results the of examples of number A situation. operational adverse the and phenomena the of character transient and dynamic the of because difficulties with fraught are these yet measurements, on rely to necessary is it sources the of significance relative the determine To ofproduce.type theyplumes that dredging environmentalto effects).avoid adverse restricting by mitigation provide that zones times essentially are which ( windows environmental choice operationofdredging and (relating ofto plumes)plant the sourcessediment C:\windows\TEMP\dpcarticle2.doc      that environment a of assessment framework following theis based steps: on Such types different indicative An steps. it. the within operate the that dredger of types the accommodate different the and inform zone maritime the to inform characterise to flexible to required sufficiently required be steps actions must the and framework is, information the That and process plumes. decision-making dredging from the assessing arising for framework effects structured a environmental of components necessary the indicates report project The Towards Assessment an Framework L: AE/ / AE0911 DPCarticle2.doc 88891 7222 (+44)(0)20 Telephone [email protected] 3AU. SW1P London, Gate, Storey's 6 CIRIA, from obtained be can report the purchase to how on Details 2000. Summer in published be to due is report project The of effectiveness and use ideas furtherwithin are developed the report. the improve significantly These proposed. be not should however, standards, Absolute would future. the in collected data monitoring protocols monitoring of adoption and agreement the that apparent also is It effects. environmental of predictions and models the inform to required are studies generic detailed that clear is it Therefore, monitoring. effects environmental and plumedetailed undertake to operation dredging every expect to unrealistic is it that stresses report The   as are this achieving towards  steps assessment key accepted the widely short, In comprehensive, follows: a transfer. achieve knowledge better to and necessary framework research future to and the knowledge current in provide gaps the address to aim out set project the from recommendations The a DevelopingFramework Comprehensive Assessment of consequences physical the be to plume becausegeneration, effectsfrom the biological thephysical flow change. has however, research, for priority The result. that changes the our knowledge of and the ‘functioning’ of of ariseplume the actual that the sediment impactsfrom can inform both to essential are data field validated consistent, that clear is It framework. assessment an inform to required tools and data the describes 600 RP knowledge, our in gaps still are there Although determiningenvironmentalwhethertheeffects are acceptable. predicting the environmental effects definingthenature of the environment definingthenature of the plume dredgingdescribingthe project should be based on the draft framework, and the outcome of which will be a comprehensive a be will which of outcome the and assessment fielddata. system validated based on framework, draft the on based which of be structure the should plumes; sediment of assessment the on guidelines practice good produce and monitoring development research, through process assessment the in gaps technology and knowledge the fill assessment an and the information required to inform the decisions make to required steps method the indicates that framework assessment an adopt

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