Beach Nourishment Beach Nourishment Beach nourishment also referred

Beach Nourishment

Beach Nourishment • Beach nourishment— also referred to as beach replenishment or sand replenishment —describes a process by which sediment (usually sand) lost through longshore drift or erosion is replaced from sources outside of the eroding beach. • A wider beach can reduce storm damage to coastal structures by dissipating energy across the surf zone, protecting upland structures and infrastructure from storm surges, tsunamis and unusually high tides. • Beach nourishment is typically part of a larger coastal defence scheme. • Nourishment is typically a repetitive process, since nourishment does not remove the physical forces that cause erosion; it simply mitigates their effects. • Sand has to come from somewhere AND constantly replaces as longshore drift removes it. • CASE STUDY – Swanage Bay – 90 000 cubic metres of sand was added to the beach at Swanage Bay in 2006. The sand came from nearby Poole Harbour.

Sand Dune Regeneration Marram Grass

Sand Dune Regeneration • Dune regeneration basically involves artificially creating new sand dunes along the coastline to act as a buffer between the land the sea. • Sand dunes occur naturally but are under threat because they are fragile and people walk all over them, ride horses and motorbikes on them and destroy the dune ecosystem. • Using fencing to help trap sand, planting Marram grass into coconut matting (as was done at Seaton Sluice) and encouraging dune formation helps to protect these systems which protect our coastline and absorb storm and wave energy. • This can cost £ 2, 000 per 100 m and helps to maintain the ecosystem of the area whilst offering protection. • However, it is time consuming to plant the Marram grass and fence off areas, and is less effective than hard engineering schemes. • CASE STUDY – Holkham Bay, Norfolk – fences built around the dunes.

Salt Marsh Creation

Salt Marsh Creation • Salt marshes act as a natural buffer between the land the sea. • Sea water can reach in salt marshes at high tide therefore they are intertidal areas of land • Salt marsh is an environment in the upper coastal intertidal zone between land salt water or brackish water, it is dominated by dense stands of halophytic (salt-tolerant) plants such as herbs, grasses, or low shrubs. • These plants are terrestrial in origin and are essential to the stability of the salt marsh in trapping and binding sediments. • Salt marshes play a large role in the aquatic food web and the exporting of nutrients to coastal waters. • They also provide support to terrestrial animals such as migrating birds as well as providing coastal protection. • CASE STUDY – Alkborough Flats in the Humber Estuary (page 157).

Managed Retreat Let the sea take its course…

Managed Retreat • Managed retreat is a method whereby we humans concede defeat to the power of the sea and allow it to erode and create salt marshes for example. • We can also allow cliff erosion to occur in areas of low value farmland just compensate farmers for their losses, rather than construct more expensive coastal defences. • This can only work where the coasts of compensation are significantly less than the coasts of building coastal defences, and can be a cheap option. • It can also be beneficial to plants and animals by providing new habitat. • This method is highly controversial however, as land is lost and the human cost can be greater than just financial. • Imagine a farmer told to quit land a family home that could have been in the family for generations because the council do not want to build a sea defence - the trauma of this is huge. • People can lose land houses and their businesses • Habitat is created for wildlife