A coastal zone can be defined as an area of activity rather than an area contained by boundaries. The term refers to a densely populated area of economic significance located at the interface between land and water. These areas change frequently due to chemical, biological, and geological attributes.
Coastal zones evolve and come into existence due to tectonic forces and meteorological conditions. Rugged coast lines with sea cliffs and marine terraces are known as emergent coast lines. This type of coast line is caused by an uplift of the land relative to the sea and is created by tectonic forces. A submerged coast consists of gentle, sandy shore lines. These coastal zones were created as the result of the sea level rising at the end of the glacial ages.
The interactions between the ocean and the land cause coastal zones to often change geographically. High winds and waves along the coast deposit sediment and erode rock and land on a continual basis. These zones are also vulnerable to natural hazards, such as hurricanes. While a coastal zone can be a risky area in which to live, it is also traditionally the most densely populated area of a country.
Administering the defined boundaries of a coastal zone is particularly difficult due to the interconnectedness of water and its effects between countries. Many countries consider the end of the continental shelf, or around 650 feet (200 meters), to be their territorial limit. Placing limits on a coastal zone is often ineffectual, however, as water pollution and contamination produced by one country can affect those surrounding it.
Historically, coastal zones have been of utmost importance for human settlement as these areas have facilitated importing and exporting and communications. Continual industrial activity over the course of many years has often led to overdevelopment and environmental degradation. Defining a coastal zone and reaching boundary and environmental care agreements has become a priority among many countries to help preserve the land and oceans.
Coastal erosion is perhaps the biggest culprit in shifting and changing coastal zones. Erosion makes the process of defining these zones all the more elusive, as it naturally moves vast amounts of sediment every year. If natural erosion is compounded with human activities, such as extracting sand from coastlines, it can cause the erosion process to rapidly increase.
The landward parts of a coastal zone tend to be most adversely affected by habitat loss and degradation. Space consuming developments of industries, ports, tourism, and recreation have often led to damage and destruction of coastline habitats, and can interfere with the delicate balance of these areas. Repairing coastal areas seems to be a nearly impossible task. Most measures taken to correct and stabilize coastal erosion have been damaging, and interrupt the natural process of coastline regeneration. Often, the best method for preserving coastal zones is minimizing human contact and development along shores and inland.