THE UK MARINE AGGREGATE REGIONAL ENVIRONMENTAL ASSESSMENT - AN EFFECTIVE MODEL FOR REGIONALISED DREDGING AREAS WORLDWIDE?

摘要

Where multiple dredging operations occur within a spatially limited area there is the potential for cumulative impacts on sensitive receptors, both at a local and regional scale. In the UK, the potential impact of cumulative dredging activities has been investigated in a series of Marine Aggregate Regional Environmental Assessments (MAREAs) undertaken for regional blocks off the South Coast, the Thames, East Anglia and the Humber. The MAREAs assess the cumulative impacts of dredging using the outputs of regional-scale numerical models (which predict the effects of aggregate extraction on hydrodynamics), linked to regional scale mapping of sensitive receptors. GIS is used to map effect and receptor footprints to determine the degree of interaction. The purpose of this step is to establish whether a receptor is likely to occur within the footprint of an effect and so be potentially susceptible to the effects of dredging. Where the effects of dredging co-occur with receptors, the area of overlap is considered indicative of an 'effect-receptor interaction'. The MAREA characterises and establishes the context of a region in terms of its physical, biological, human (heritage and socio-economic) value and future dredging activities and delivers a range of regional datasets which will aid the progression of dredging operations. This paper will describe the MAREA methodology in a UK context, and suggests that similar regional data gathering could provide valuable information on the effects and impacts of multiple dredging operations, as well as the interaction with other users of the marine environment, in other regions of the world e.g. Western Europe, Australia and the USA.