10. Coastal Management

The need for coastal protection - Australian Beach

Watch the video on coastal erosion in Australia and answer the following questions:

•How does climate change cause the coastline to slowly disappear? How does it then affect property owners?

•What is the problem with building rockwalls to protect housing along the beach?

•How is the government trying to slow down the pace of erosion? How effective is it?

Watch the video here on soft engineering at Somerset Coastline

https://timeforgeography.co.uk/videos_list/coasts/soft-engineering-beach-management/

What are the two strategies used?

How do the strategies help to protect the coast?

Why must a balance be obtained in protecting the coast and for developing the area for the economy?

Hard & Soft Engineering

Work in group

Identify and classify the different methods of coastal protection.

List down the advantages and disadvantages of each method.

Soft engineering:

  • beach nourishment,

  • planting vegetation,

  • Stablizing sand dunes

  • corals.

Hard engineering:

  • seawalls,

  • tetrapods,

  • gabions,

  • groynes

  • breakwater.

Focus on:

  • where these methods can be found

  • how these methods work

  • advantages and disadvantage of such methods

Soft engineering does not involve the building of structures.

From Google Earth

Beach nourishment

The photographs and videos below were taken by me in Singapore, Malaysia and Taiwan - can you identify the coastal management strategies?

Beach replenishment - sand dunes have also been formed and the weed had started to grow on them and stabilising it. Klebang in Malacca, Malaysia (2017)

Beach nourishment at Siloso beach, Sentosa (2019). Look at how strong the waves are. A limitation of the measure is that the sediments continue to get eroded and there is a need to replenish the sediments again.

Mangrove in Pulau Konet at Malacca, Malaysia (2017)

Mangrove in Pulau Kukup, Malaysia (2017)

Hard engineering involves the building of man-made structures such as gabion, sea wall, tetrapod, breakwaters and groyne.

Gabion taken at Pulau Kukup 2017

Gabion along the coast of Langkawi, Malaysia taken by June in 2019.

Tetrapods protected the coastal areas of Taiwan. Photo taken near Yeliu, northern part of Taiwan (2016)

Does this work better than sea walls?

Look at the size of Tetrapods. Photo taken by my former student Tony Aw in Cijin, Taiwan.

Aerial view of the breakwaters along the coast of Kaohsiung (2016), Taiwan.

Seawalls at Labrador Park, Singapore (2012)

Rock armour protecting the Siloso beach (2019)

Seawall near Siloso beach (2019)

Sea wall at Jalan Delima 6, Pontian in JB, Malaysia (2016). The video below shows how strong the wave is

Breakwaters at East Coast Park, Singapore (2016)

Look at how badly eroded the base is from the photo taken at ECP (2019) due to coastal erosion.

https://www.straitstimes.com/politics/parliament-first-of-coastal-protection-studies-to-commence-this-year-jurong-island-east

The coastal land at Changi is so badly eroded that it will give way soon. Photos taken in Dec 2020

Sand bags have been placed to protect it from erosion. How effective do you think this will be?

The erosion is so bad that the roots of trees are exposed.

Seawall protecting the another stretch of the coastal land and chalet behind it in Changi. However, you can still see the erosion at work in the foreground.

Look at the coastal erosion threatening the footpath behind it.

Using Google Earth to explore the hard engineering measures.

Breakwater at West Sands, UK

Groyne and seawall at Selsy, UK.