Soft Engineering Measures

Soft Engineering Measures

1. Beach Nourishment

   • DESCRIPTION: It involve using sand from an external source to replenish the sand on a depleted beach. This sand may come from another beach or be dredged from the sea floor.
   • ADVANTAGES
     • EXAMPLES: Cape May Point, New Jersey,USA - Sentosa, Singapore
     • 1.Slows down the erosion of beaches (offers protection to inland area)
     • 2.Aesthetically pleasing
   • DISADVANTAGES
     • 1.Trucking or piping in sand was expensive & time-consuming
     • 2.Sand used for beach nourishment was washed out to sea and suffocated the corals
       • EXAMPLES: Coral reefs at Waikiki Beach
     • 3. Re-nourished beaches can be eroded again

2. Planting Vegetation & Stabilising Dunes

   • DESCRIPTION: 1. Planting vegetation help stabilise coastlines. 2. Sand dunes can be stabalised by planting grasses.(planting vegetation)
   • ADVANTAGES
     • VEGETATION - Mangroves absorb wave energy through their dense root system.
     • SAND DUNES - The roots of grasses anchor the sand & prevent erosion.
       • PROCESS: Matting is put over the dunes & young grasses are planted into the sand through the matting. Over time, the grasses become established & dunes become stable.
     • EXAMPLES: Triton Place, Western Australia
   • DISADVANTAGES
     • VEGETATION -Take many years to established before it can resist natural & human elements
     • VEGETATED DUNES - Fence & access paths built to prevent human traffics - Expensive to maintain (need to be replaced with taller ones as sand accumulates)

3. Encouraging Coral Reef Growth

   • ADVANTAGES
     • Help weaken wave energy
     • Breeding ground & nursery for fish
   • METHOD 1: Artificial reefs created by placing lasting materials onto the sea floor. Corals, marine creatures & vegetation colonise these materials & start to function as a natural reef.
     • EXAMPLE: Palau in the northern Pacific Ocean, sunken ships from WWll naturally colonised by corals
   • DISADVANTAGES
     • 1.Sites need to be surveyed to ensure maximum growth
     • 2. Dangers of siltation need to be overcome
     • 3. Slow coral growth 20-30 years - insignificant
   • METHOD 2: Coral-growing programme. A structure of welded construction steel rods charged with low-voltage solar-generated electricity help to speed up coral growth. (3-5 x faster)
     • EXAMPLE: Maldives, Indian Ocean