Peter W. French ROUTLEDGE ENV1RONM.ENTAL MANAGEMENT S E R I E S

Transcription

1 COASTAL AND ESTUARINE MANAGEMENT Peter W. French ROUTLEDGE ENV1RONM.ENTAL MANAGEMENT S E R I E S

2 Contents List of piales vii List of figures vni List oftables x List ofboxes xii Preface xiii Acknowtedgements xv 1 Introduction to estuarine and coastal systems 1 Introduction 2 Types of estuarine and coastal environments 8 Human impacts on coasts and estilarles 14 Summary of Chapter The physical regime of coasts and estuaries 25 Introduction 26 Wave-dominated coasts 26 Tide-dominated coasts 41 Coral reefs 49 Wind-dominated (aeolian) coasts 50 Deltaic coastlincs 51 Summary of Chapter Land claim and coastal defence 55 Introduction 56 History of land cíaim 57

3 COXTENTS Environmental implications of land claim 58 Coastaí protection 71 Coastal defence managcment and planning 104 Managcd realignment: a universal solution in soft engineering? 110 Summary of Chapter The industrial use of coasts and estuarics 117 Introduction 118 Historical trends in \vaste disposal 121 Effccts of pollution on estuaries and coasts 130 Effects of power generación 137 Summary of Chapter Coastal development for-tourism 147 Introduction 148 Problems of tourist development at the coast 150 Demands of the tourist industry 160 Examples of tourist impact on coastlines 165 Summary of Chapter Causes of indirect impacts on the coast 171 Introduction 172 Inland causes 172 Offshore causes 177 Summary of Chapter Management frameworks for coastal and estuarine systems 187 Introduction 188 The concept of coastal zonc management 191 The future of the coastline 208 The way forward 217 Summary of Chapter The final word 221 Referentes 223 Location índex 245 Subject Índex 248

4 Plates 2.1 Beach cusps formed as a rcsult of a combination of shore-normal and shore-parallel currents to form rips The combination of high tidal range and rapid narro\ving and shallowing of an estuarine channel resulting in the formation of a tidal bore wave A wide intcrtidal sandflat fronting a dune complex Largc borrov pit fronting a sea bank Tvpical earth embankment protecting land claim from tidal inundation The use of brushwood groynesío increase sedimentación in the intertidal zone A simple trample prevention management measure in sand dunes Wooden bridge allowing bcach access across large sea defence blocks 161

5 Figures 1.1 Dcvelopment of the coast as scen from a human perspectiva Development of the coast as seen from an environmentai perspective Generalised trends of coastal erosión and accretion in the USA and the UK ó 1.4 Simplified process diagram ío show the intcraction of main components of coasta! processes Delineation of coastal cell boundaries for the UK The coastal system Environmentai controls of scdiment deposition and erosión in a wave-dominated beach system Effects of foreshore shallowing on the wave form Effects of sea floor rnorphology on wave front refraction, and the subsequent concentration of waves at headlands Wave impact on beaches dominated by shore-parallel currents, and the impacts on the rcsulting morphology of groynes Interaction of shore-normal and shore-parailel currents to produce rip currents Typical cbncordant and discordant coastlines Effect.of different relationships of resístant and Icss resistant rocks in clíff morphology Controiling factors in cliff stabüky Effect of frcquency of tidal inundatíon on the vertical accretion rates of receñí: salt marshes Relationshíp of current velocitv to intertidal depositional environments Variation of salt marsh types in a range of tidally dorninant environments 46

6 3 1 Impact of land clairn on the intertidal área of the Tees, north-east England Impact of land claim and sea wall construction on the intertidal área oían estuary 61 i 3 Effect of sea wall construction on intertidal habitáis Impact of dredging on an estuarinc deep water channcl Áreas of unprotected erodíng cliffs in England Impact of cliff protection along a coastline Díagramrnatic representation of typical heavy metal concentration v. depth trends from polluted salt marsh sequcnces The Scvern esruary and Bristo! Channcl system as an example of the causes of estuarine and coastal pollution, and the various transport pathways Point sources of pollution input in the Severn estuary and Bristol Channcl Age distribution for the occurrence of rnajor pollutants in sedimentary deposits Accumulation of DDT up an esuiarine food chain Simplified section of the impounded water behind the Tawe barrage, south Wales Number of proposed marina and mooring developrnents, by county, in England Hypothetical storm hydrographs for rural and urban catchments Framework for the integration of the various management plans into an overall coastal strategy 208 FIGURES

7 Tables 1.1 The time scale of coastal changes in relation to both absolute and human time scales The contrastmg forms of agent dominance at the coast and their resulting landforms The potential human impacts on coastal environments, and their significance with respect to change The extent of land claim in some UK estuaries The loss of coastal habítats as a result of land claim in a range of coastal environments Practical considerations in the decisión as to whether or not to construct sea defences Some examples of beach renourishment studies from around the world The relationship between salt marslr width and the required height and cost of the sea wall The relevance of coastal and estuarine sites for industrial developments The relative importance of different transport media in the supply of metal pollution in the Sevcrn estuary A comparison between natural and anthropogenic rates of heavy metal input The costs of developing and utiíising tidal power in some UK estuaries Oil tanker accidents since 1967, and their impacts on the coast The increased environmental information avaiíable to the coastal planner as a resuít of increasíng the área of coastline used for data-gathering The relationships of statutory and non-statutory management initiatives at national, regional, and local levéis 191

8 7 } Sclect bibliography of coaslal zonc management initiatives in different countries Select bibliography of sea level rise studies from djfferent countries 211 T A B L E S

9 Boxes 3.1 Loss and predicted loss of intertidal habitats along the coast of England Coastal protection and its impaces along che Fylde coast, north-west England The relationship of windiness to marsh erosion/accretion cycles in the Scvern estuary Removal of marsh clay in the Medway estuary for brick-making The relationship of nuclear instaliations and coastal stabííity in the UK Disposal of the Brent Spar: arguments for and against land-based salvase 181