Embedded Files
Environmental change
Environmental change
40 years of sand dune rehabilitation at CronullaYouTube | Soil Conservation Service (5:17min)
In 1974 the NSW Government initiated a 40 year Beach Improvement Program at Cronulla.
The program was delivered in partnership between the Soil Conservation Service and Sutherland Shire Council.
The aim of the program was to stabilise the dune system and prevent the erosion of Kurnell peninsula.
Watch the video to see whether it was successful and where the future of the work is headed.
Human activity
Human activity
Activity 5: Human induced change
Activity 5: Human induced change
Location of the Greenhills Beach suburb in relation to our study site
The Kurnell sand dunes have undergone a number of human induced changes, since land was first sold off in the 1800s.
From the 1930s to the 1990s, sand mining of the Kurnell dunes is estimated to have removed over 70 million tonnes of sand.
Today, human impact is most evident in the continued development of the area, including the 2010 decision to build the Greenhills Beach suburb on the dunes.
Open EarthEngine and search for Cronulla. View the time lapse of this area and consider:
Can you identify the areas where sand mining has occurred?
Locate the Greenhills Beach suburb. In which year does it become noticeable?
Climate Change
Climate Change
Climate change is affecting the world's oceans in more ways than one.
Watch NASA's explanation and identify the two ways it is impacting sea levels.
Rising Tides: Understanding Sea Level RiseYouTube | NASA Climate Change (1:54min)
Activity 6: Storm surges and east coast lows
Activity 6: Storm surges and east coast lows
During storms, sea level rises temporarily. This is called a storm surge. It is caused by the storm’s low pressure and winds pushing water towards the coast.
If this happens at high tide, the sea can be several metres higher than normal. This can cause flooding and damage to buildings and other structures.
This video from August 1986 shows how high the sea level rose at Cronulla during a severe storm that coincided with a king tide (an especially high tide).
1986 August storm at CronullaYouTube | UNSW Water Research Laboratory (1:04min)
East coast lows (ECLs) are extreme weather events that occur along the eastern coast of Australia several times a year. ECLs are often significant storms that damage infrastructure, such as houses and sea walls, and erode foredunes.
ECLs can form over a 12-24 hour period and often result in:
gale force winds
heavy rainfall which can lead to flooding
large sea swell which can damage the coastline.
Meteorologists predict extreme events such as ECLs may increase in the warmer conditions produced by climate change.
Cronulla beach restaurant Zimzala smashed as huge waves hit coastYouTube | STUDY SERIOUSLY (0:43min)
From 4-6 June 2016 Australia's east coast was hit by a significant east coast low. This video shows the impacts of large swell on one of Cronulla's waterfront restaurants, Zimzala.
Watch the video. Then locate Zimzala on your site MyMap (from the Introduction).
Identify other coastal infrastructure you think would be at risk during an ECL.
Describe the type of waves that occur during ECLs. Relate this to the impact of ECLs on the dune system.
Activity 7: Rising tides
Activity 7: Rising tides
The combined effects of east coast lows and sea level rise could increase impacts on our coast and coastal infrastructure in the future.
In a natural system, sand dunes adapt to changing sea levels by moving further inland. In this way, they continue to provide natural protection for the coastline.
Where development occurs close to the beach, there may be no space for sand dunes to form, or retreat. This leaves the land unprotected and vulnerable to damage from storms.
Sea level rise could threaten the Cronulla coastline
The Coastal Risk Australia (CRA) viewer is an interactive map which allows you to predict what the Australian coastline may look like in 2100. Use this tool to investigate which areas of the coast are predicted to be inundated due to sea level rise:
Search for Cronulla from the home page.
Compare the the current high tide level for Cronulla and the predicted high tide level in the year 2100.
Predict which areas might suffer damage from sea level rise in the future.
Switch from predicted to manual mode. Drag the height until it is 2m above sea level. This simulates a sea level rise of 1m plus a storm surge of 1m. Which areas are most at risk?
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