Classification of Coasts
The classification of coasts is based on their formation and features. Coasts can be categorized as primary or secondary, based on their origin. Primary coasts are formed by geological processes, while secondary coasts are shaped by factors such as erosion and deposition. Additionally, coasts can be classified as emergent or submergent, depending on whether they are rising or sinking relative to sea level.
5 Key excerpts on "Classification of Coasts"
- Gerd Masselink, Michael Hughes, Jasper Knight(Authors)
- 2014(Publication Date)
- Routledge(Publisher)
...Most early classification schemes are based on the role of sea-level variations, and so distinguish between submerged and emerged coasts (Johnson, 1919). Submerged coasts include drowned river and glacial valleys, termed rias/fjards and fjords, respectively. Coastal plains are characteristic of emerged coasts where sea level has fallen. Shepard (1963) identified primary and secondary coasts. Primary coasts result mainly from non-marine processes and include drowned river valleys, rocky and deltaic coasts. Secondary coasts result mainly from marine processes or organisms and include barrier coasts, coral reefs and mangroves. Coasts can also be classified with respect to their tectonic position (Inman and Nordstrom, 1971). Leading edge coasts, also termed collision coasts, are located adjacent to subducting plate margins such as along the Pacific coasts of South America, Japan and New Zealand. Here, tectonic processes have formed mountain belts that have steep, erosive and rocky coastlines, boulder beaches, and falling relative sea levels. Trailing edge coasts, however, are located away from subducting plate margins, are tectonically benign, older and of lower elevation. Examples are coasts of Africa, Australia and Atlantic coasts of North and South America. These coasts are typically sediment-rich, progradational, with large deltas and sandy beaches. The main shortcoming of these classifications is that they emphasise geological inheritance rather than hydrodynamic processes that shape coastal land-forms. Davies (1980) identified coastal types based solely on wave height and tidal range. Because waves are generated by wind, the distribution of wave environments varies by latitude, reflecting global climate zones (Figure 1.4). Coastlines dominated by storm waves are located in higher temperate and arctic latitudes, whereas swell-dominated coasts are located in lower temperate and tropical latitudes where cyclones (hurricanes) are also important...
eBook - ePub- John Roff, John Roff(Authors)
- 2013(Publication Date)
- Routledge(Publisher)
...locations Temperature and salinity variations Seasonal stratification Land drainage Annual, seasonal productivity regime, dominance of pelagic or benthic realm HUMAN Fishing gears Engineering construction/shoreline stabilization Eutrophication nutrients Water supply/elimination Waste disposal Resource use: sand gravel extraction fisheries mangrove use coral use Drainage modification, saline intrusion into aquifers Tourism Wetland degradation and reclamation Wildlife exploitation Climate change effects Erosion/deposition Table 11.2 Types of coasts Coastal types: collision coasts trailing edge coasts marginal coasts Mountain coast Narrow shelf: headlands and bays coastal plain Wide shelf: headlands and bays coastal plain Deltaic coast Reef coast Glaciated coast Ria coast Fjord coast Unglaciated lowland coast Note: The type of coast significantly determines sources, sinks and types of sediments and their dynamics and distributions. This in turn largely determines the types and distributions of biological community types. Note that many other terms are used to describe the geology and geomorphology and evolution of coasts Source: After Carter (1988) and Guilcher (1958) Coastal zones are of various types (Table 11.2); they have attained their characteristics by a variety of geological processes and interactions, and undergo various stages in their evolution (see Carter, 1988). Regions of the coastal zone may be dominated by one or more of a set of physical processes, on a range of time scales, including wave activity, tidal range and currents, and river inputs (Figures 11.2 and 11.3). The coastal zone is in a constant state of flux and modification over time (see Figure 11.3), and is subject to a variety of influences...
eBook - ePub- Riki Therivel, Elizabeth Wilson, Donna Heaney, Stewart Thompson(Authors)
- 2013(Publication Date)
- Routledge(Publisher)
...At present, there is no definition of the ‘coastal zone’. Coasts certainly include a landward component, a marine component, and the inter-tidal area, but any existing working definitions are based on a combination of administrative, practical, economic and environmental factors. The PPG on coastal planning (in draft at the time of writing) defines the coastal zone as the area extending seawards and landwards from the coastlines, where land and marine influences interact. This allows some scope for developers to challenge the interpretation adopted by particular local authorities. A report from the Marine Conservation Society (Gubbay, 1990) suggests that the seaward boundary should correspond with the 12 nautical mile limit of UK territorial waters. Inland boundaries are harder to define because of the many administrative boundaries. In Heritage Coasts the main factors determining inland boundaries are topography and land use. At present, some management and planning initiatives are already in operation at local, regional and national level, and these provide useful examples of both the advantages and difficulties of establishing an SEA system for coasts. However these tend to deal with particular uses of the coast rather than all of the uses, or with very specific areas of coastline. The biggest gap appears at the national level where those initiatives that do operate (Preferred Conservation Zones and Preferred Development Zones for the oil and gas industries) are not concerned with integrating all uses of the coastal area. It is at this level that attention must be focused for truly strategic planning for coasts. Many government departments, statutory bodies and other groups have statutory duties and powers related to coastlines...
eBook - ePubThe Geography of Tourism and Recreation
Environment, Place and Space
- C. Michael Hall, Stephen J. Page(Authors)
- 2014(Publication Date)
- Routledge(Publisher)
...Heritage Coastline and Area of Outstanding Natural Beauty in England and Wales), the impacts of tourism and recreation are multifaceted. In the wide-ranging study by the German Federal Agency for Nature Conservation (1997), the dominant coastline regions globally were the Mediterranean, the Caribbean, the Gulf of Mexico, the Indian Ocean islands, Australasia and the Pacific islands. In this context, the coastal resource is a global environmental issue which is complex, diverse and not simply reduced to beach resorts, as the discussion has alluded to so far. (See Visser and Njunga’s (1992) examination of the Kenyan coastline, where the ecological diversity in the coastal environment comprises coral reefs, sea grass and seaweed beds, mangrove forests, sand dunes and inland tropical forests.) According to the German Federal Agency for Nature Conservation (1997), coastal tourism environments may be categorised as follows: oceanic islands; coral reefs; offshore waters; mangroves; near-coastal wetlands; sandy beaches; coastal dunes. The environments under the greatest recreational and tourism pressure are sandy beaches, followed by coastal dunes (see Nordstom et al. 2000 for a review of management practices to restore dunes). Within a European context, the principal erosion and sedimentation processes affecting coastal environments are related to natural processes, including: wave and tidal action; geomorphological factors (e.g. rivers which impact upon the river mouth and deltas); meteorological factors (e.g. wind and storms); changes in sea level; geological processes (e.g. seismic and volcanic activity). In addition, the European coastline is also subjected to a great number of environmental stresses, to the point where some researchers consider it to be under the greatest pressure of any coastal environment globally (German Federal Agency for Nature Conservation 1997; Hall 2006c). For example, Jiménez et al...
eBook - ePub- Rattan Lal(Author)
- 2017(Publication Date)
- CRC Press(Publisher)
...Consequently, geologic/geomorphic-based landscape classifications are inherently more durable and reflect dominant conditions (longer term equilibrium conditions). Soils do not immediately re-equilibrate to reflect ecosystem shifts. Soils do adjust to longer term (10s to 100s of years) environmental conditions and eventually reflect new ecosystem equilibriums in their morphology and properties. Landscape classification The identification and subsequent placement of different types of landscapes into some order or array. Grouping individual but related landforms into clusters (i.e., landscapes) provides a meaningful, utilitarian, and common sense way to subdivide the natural continuum of the earth’s surface. Historically, landscapes have been defined by transportation, management, or resource circumstances. Each identified landscape establishes a context, a suite of realities that establish land management opportunities and limitations. Areas that present similar restrictions to travel (e.g., mountains) or are subject to similar hazards (e.g., floodplain) give rise to practical groups. In geology and soil science, emphasis has been placed on morphometric and compositional attributes that have useful applications, such as limitations for road or housing construction, opportunities for food or fiber production, or building material extraction...
