Video 1 – costal erosion Boiol242 Week 3
Sandy beaches are a dynamic system that naturally experiences phases of erosion and accretion. Storm systems producing high energy waves that can rapidly erode sediments, particularly when infrequent or intense. During calmer periods, average swell waves deliver sediment back to the shoreline (beach accretion).
Beach accretion is a much slower process than erosion whereby it’d take severl years for a beach to return to its pre – storm condition after a major storm or several smaller storms in a quick succession.
Across australia’s coastline beach erosion and accretion occurs with little / no impact on human settlements , however the problems are when;
- Buildings on sandy beach systems are subject to natural phases of erosion, modification to …show more content…
They prevent sand exchange between dunes and beach, thus the beach can’t supply new sand to the island dunes, nor flatten as it tends to do during storms
Well designed groyn = semi permeability with sediment transfer – eccess sediment is free to move on through the system
Bad designed groyn = trapping too much sediment - causing severe beach erosion on the down – drift side
Ecological impacts:
Habitat destruction due to completely vertical sea walls.
Video 4 Coastal engineering response: soft engineering
Beach scraping and beach nourishment
Beach scraping : mechanical enquipment scraping sand from lower part of the beach up to/just below the sand dune.
- ‘tis a temporary measure to attempt to protect upland property during a storm
Beach nourishment: Dredge from an external site and adding it to an eoridg beach to extend it seward.
- ‘tis globally propular as it preserves beach resources and is perceived to avoid the negative effects of hard structures
Activity: does beach nourishment’s ecological benifets outweigh the
Sandy beaches are a dynamic system that naturally experiences phases of erosion and accretion. Storm systems producing high energy waves that can rapidly erode sediments, particularly when infrequent or intense. During calmer periods, average swell waves deliver sediment back to the shoreline (beach accretion).
Beach accretion is a much slower process than erosion whereby it’d take severl years for a beach to return to its pre – storm condition after a major storm or several smaller storms in a quick succession.
Across australia’s coastline beach erosion and accretion occurs with little / no impact on human settlements , however the problems are when;
- Buildings on sandy beach systems are subject to natural phases of erosion, modification to …show more content…
They prevent sand exchange between dunes and beach, thus the beach can’t supply new sand to the island dunes, nor flatten as it tends to do during storms
Well designed groyn = semi permeability with sediment transfer – eccess sediment is free to move on through the system
Bad designed groyn = trapping too much sediment - causing severe beach erosion on the down – drift side
Ecological impacts:
Habitat destruction due to completely vertical sea walls.
Video 4 Coastal engineering response: soft engineering
Beach scraping and beach nourishment
Beach scraping : mechanical enquipment scraping sand from lower part of the beach up to/just below the sand dune.
- ‘tis a temporary measure to attempt to protect upland property during a storm
Beach nourishment: Dredge from an external site and adding it to an eoridg beach to extend it seward.
- ‘tis globally propular as it preserves beach resources and is perceived to avoid the negative effects of hard structures
Activity: does beach nourishment’s ecological benifets outweigh the