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Bullet River and Sea Erosion
Home » Hydro Meteorological Disasters » River and Sea Erosion

Mitigation measures
In order to provide a comprehensive guide to the options available for the management of coastal erosion all principle coast protection and erosion management techniques are covered. It must be recognised, however, that finely all of these can be damaging to the natural environment, to a greater or lesser degree, in inappropriate situations. The inclusion of any particular approach herein does not, therefore, indicate that it is, necessarily, environmentally sensitive, nor are universally appropriate as a means of managing erosion. Rather, the summaries highlight and encourage the pursuit of good practice, from an environmental perspective, which ever approach is deemed necessary by the circumstances concerned.

The remedial measures should be selected after proper investigation and model studies. It must be ensured that protection measures do not shift erosion problem from one site to some other site. The measures to control erosion include non-structural and structural or their combination.

Structural measures used for coastal erosion prevention are as follows:
  • Sea wall/ Revetment: Seawall may be useful in case of protection of specific area from erosion and storm surges. Adverse effect is experienced on downstream side.
  • Groynes: Groynes may be adopted to stop or decrease shoreline recession and for beach formation. However, extremely adverse effects are observed on downstream side and groynes should be avoided unless their main purpose is to keep a beach at one particular position at the cost of adjoining areas.
  • Off-shore breakwater : These may be adopted for shore protection and beach formation. Severe downstream erosion may result due to littoral barrier effect. It is an expensive option and needs regular maintenance to avoid rapid breakdown of breakwater.

Soft-structural measures generally adopted to reduce/prevent coastal erosion are:
  • Artificial nourishment of beaches : Beach nourishment may be adopted for protection and beach development. Combination of nourishment of beaches with seawall/groynes will create beach in front of protected area and eliminate leeside erosion.
  • Vegetation cover such as mangrove and Palm plantation : Vegetation cover can restrict sand movement and erosion.
  • Sand bypassing at tidal inlets : Severe erosion problem has been experienced due to construction of jetties and/or dredged channels. This problem can be solved by bypassing of material from the updrift side of inlet to the downdrift side.
Out of these measures, the techno-economically viable and site-specific suitable measure should be adopted. Combination of the above measures may give optimum results with least adverse effect on down drift.
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