Controlling human induced coastal erosion


  • Reactive shoreline erosion control
  • Preventing coastal erosion
  • Preventive shoreline erosion measures
  • Coastal bioengineering

Description

There are three basic methods of shoreline or coastal erosion methods: Vegatative; involves the planting of trees or woody shrubs for the soil binding properties of their large root systems, grass and other herbaceous plants to protect against raindrop impact and scouring from surface runoff, or emergent acquatic plants to stabilize bottom sediments and dampen wave action. Structural: includes protective structures and the placement of rock of various sizes (referred to as rip-rap). Other structural methods include bulkheads, gabions (rock filled baskets), sandbags filled with concrete, and railway sleeps. These methods are often visually unappealing, require heavy equipment and technical expertise, and may be more prone to failure in comparison to simple rip-rap. Manipulative: used on streams, this includes removing streamflow obstructions, grading shoreline banks or rerouting the stream channel.

Context

One way to control coastal erosion is through preventive measures. These include: Preserving the rocks and vegetation which naturally occur along the coastline; Preventing impervious surface (i.e. roofs, driveways) runoff from flowing to the coastline; Prohibiting construction within 100 feet of the coastline or the edge of nearshore bluffs; Protect nearshore berms pushed up by ice action along lakeshores as they prevent excessive surface runoff and trap sand which "nourishes" the beach, and limit foot traffic and recreational activities in erosion prone area.

Wetland vegetation can stabilize shorelines by reducing the energy of waves, currents and other corrosive forces. At the same time, the roots of the plants hold the bottom sediment in place, preventing erosion of valuable land.

Implementation

This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities.

As concerns physical destruction of coastal and marine areas causing degradation of the marine environment, Agenda 21 recommends that priority actions should include control and prevention of coastal erosion and siltation due to anthropogenic factors related to, inter alia, land-use and construction techniques and practices.

A technology called bioengineering is now being used to combat coastal erosion with good success. This combines mechanical, biological, and ecological concepts to arrest and prevent coastal erosion. An example is the planting of willows interspersed with rock rip-rap. The rock provides immediate resistance to erosion. As the willows become established, roots invade and permeate the rock and underlying soil, binding them together into an erosion resistant mass.


© 2021-2024 AskTheFox.org by Vacilando.org
Official presentation at encyclopedia.uia.org