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Anatomy of a beach
Anatomy of a beach
What zones do you think are in this picture?
In the dune ecosystem there are clear interactions and linkages between the hydrosphere, atmosphere, biosphere and lithosphere.
Need a refresher? Match each biophysical process to its sphere in this Canva whiteboard activity.
The coastal dune system can be divided into a number of different zones - berm, foredune, swale and hind dune.
View a diagram of a dune profile in your Geography textbook, or view the diagram on page 3 of the Coastal Dune Management manual from NSW Department of Planning, Industry and Environment.
These diagrams show the profile of a model dune system, divided into the different zones. Notice how the types of species and heights of vegetation change as you move from the ocean towards the hind dune.
Activity 3: Virtual sand dune exploration
Activity 3: Virtual sand dune exploration
Take a virtual walk along an access path at Wanda Beach, moving through each zone, from the ocean inland.
How does the shape of the dune change as you move along the path? Does it get steeper? Are there any dips or swales?
Does the type of vegetation change as you move (e.g., height and colour)? What type of plants do you observe growing where?
Are there any indications of changes in physical conditions? Is it as windy inland as it is by the water? Where do you think it is likely to be warmer? more shaded?
360 tour of an access path at Wanda Beach
Wave action (Hydrosphere)
Wave action (Hydrosphere)
Coastal processesYouTube | Royal National Park Environmental Education Centre (4:14min) | Transcript
Beaches are dynamic, ever changing environments.
This video shows the continual changes that occur within coastal environments and explains some of the factors that drive change.
Depending on conditions, waves can either be constructive or destructive.
Constructive waves deposit sand onto the beach because the energy of the swash is greater than the energy of the backwash. These waves are smaller and occur on days when the weather is calm.
Destructive waves erode sand away from the beach because the energy of the backwash is stronger than the energy of the swash. There larger waves occur during storms and when there are strong winds.
Constructive and destructive wave diagrams
Sand dune systems are an important part of coastal environments. They are nature’s way of protecting the land against storms.
During storms, waves become larger and more destructive. Sand dunes help absorb the destructive wave energy, protecting the land behind them and providing a back up supply of sand for the waves to take.
The waves take the sand and dump it in an offshore sand bar. When the weather is calmer, constructive waves wash the sand from the bar back onto the beach. Wind then blows the sand back up into the sand dunes where plants trap and hold it.
This forms a natural cycle of erosion and deposition (taking away and adding sand) and keeps the beach environment balanced and stable.
Cartoon by Laura Hill 2021
Wind (Atmosphere)
Wind (Atmosphere)
Sand dunes.mp4Wind is a major agent of erosion and deposition in the coastal environment.
Watch the video for a demonstration of how wind impacts the dune system.
How does wind affect the distribution of sand particles?
What naturally occurring features reduce the effect of wind on erosion of sand?
Predict the impacts of removing vegetation from the dunes.
Identify the management strategies mentioned in the video. (These will be explored further on the Environmental management page).
Vegetation (Biosphere)
Vegetation (Biosphere)
Plants are an extremely important part of the sand dune system. This cartoon demonstrates the damage that can be inflicted on the coast when there is no dune system to protect it.
Plants help build and stabilise the dunes by acting as windbreaks. The dunes and vegetation slow the wind so it drops the sand it is carrying. Plants then trap the sand and their roots hold it in place.
If there is no vegetation on a dune, the wind will easily blow the sand away (erosion) and it will be lost from the system.
Cartoon by Laura Hill 2021
Activity 4: Vegetation profile
Activity 4: Vegetation profile
A vegetation profile shows the changes in plant species that occur across an environmental gradient. In a dune ecosystem, it is used to show changes as we move further inland from the ocean.
Download the Dune vegetation ID sheet.
Save a copy of the Vegetation dune profile Google Slide.
Read the description of each plant species on the Dune vegetation ID sheet.
Use the symbols provided in the Google Slide to indicate where along the dune profile each plant species occurs.
Example of a dune vegetation profile
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