After reading this chapter you should be able to:
- identify the various zones of a beach
- explain how the relationship between swash and backwash determines the composition of a beach
- define the concept of longshore transport
- identify the different erosional and depositional structures created by longshore transport
- explain the impacts associated with different forms of hard stabilization: groins, jetties etc.
- define an estuary
- identify the four types of geological estuaries, and how they form
- identify the four types of estuaries based on salinity and mixing patterns
For most people, their image of the coast is the place where the land meets the sea, most likely in the form of a beach. But it is more than just the narrow strip along the water line; technically the term “coast” refers to the range of land over which the ocean has an effect on climate, foliage, and other environmental processes. This range may extend for tens of kilometers inland from the water’s edge. Furthermore, what we recognize as the coast today, may not have been a coastal area in the past, as sea level has varied from about 6 m above to 125 m below its current height over the past two million years.
This chapter begins with the features of coastal regions, the processes that shape the coastline, and how humans try to control these processes. Following that, we will examine the different types of estuaries that are found in coastal areas.