Read: Chapters 1 and 4 in Beaches and Coasts
Definitions:
Note: Terminology varies depending on the source. For example, coastal planners may use definitions that are driven by state regulations. Terms used throughout this course are applied as defined in the Glossary of Coastal Terminology or your Text from the United States Army Corps of Engineers Coastal Engineering Manual.
With global warming leading to the prospect of increasing rates of sea level rise, studying the coastal zone has never been more important on a global basis. In Bangladesh one-meter relative sea level rise will inundated a predicted 17.5 percent of the country, displacing 13 million people. Along China's coastline the same rise in sea level would cover 125,000 square kilometers, home to 73 million people.(from Climate Alert Volume 8, No. 2 March-April 1995) In the Pacific small island nations are literally going under. Closer to home, the United States erosion rates average .6 to .9 m/yr (2-3 ft/yr) along the Atlantic Coast and are as high as 2 m/yr (6 ft/ yr) along the Gulf Coast. (Evaluation of Erosion Hazards. 2000, Heinz Center) Large coastal cities are spending billions of dollars a year protecting their infrastructure from erosion or rebuilding following severe storms. However, the engineering structures that protect the coast will ultimately lead to the destruction of the coastal wetland so vital to marine fisheries and the entire coastal ecosystem.
Read:
Cities at Risk:Assessing the vulnerability of United States Cities to Climate Change, The International Council for Local Environmental Initiatives (ICLEI) Executive Summary, 2003
The Coastal Zone: A resource at Risk, June 2002, Haines, Geotimes
Coastal Systems, 2002, Intergovernmental Panel on Climate Change (UNEP)
To man:
To other life forms:
The shore is where energy transferred through the oceans is expended on land and where sediment eroded from land is transferred into the oceans. Waves and tides move sediment both parallel and perpendicular to the shore. Solar energy, responsible for winds, and gravity provide the energy that drives nearly all coastal processes.
More than 90% of the sediment reaching the oceans is transported by rivers. Without this sediment most beaches would not exists. Fluvial and sediment discharges from streams interact with waves and tides to produce a variety of coastal landforms such as deltas, barrier islands and related coastal estuaries.
Sea level changes continually alter the region of the coast affected by shoreline processes. The present increase in sea level is causing widespread erosion that is affecting most coastal communities.
Anthropogenic activities are affecting the coast far more than we could have anticipation. Deforestation in some countries has increased flooding and sediment discharge, whereas the building of dams has trapped sediment and controlled discharge to the point where erosion now dominates regions that were once depositional. Coastal estuaries are vanishing from over population and coastal flooding has been exacerbated by the over-pumping of coastal aquifers. Pollution is destroying coral reefs and coastal ecosystems that once buffered the coast, and increased carbon dioxide and other atmospheric emissions by man are fueling climate change and sea level rise.
Sources of energy driving coastal processes
Coastal types vary tremendously according to geologic history, climate, sediment supply, wave and tidal regime, and other local influences. Some of the more common coastal types are listed below. A more comprehension discussion of coastal features will be covered my lecture on the classification of coasts.
(see coastal influences)
Lindley
Hanson/email /Gls214
Department
of Geological Sciences, Salem State
College, Salem, MA