CoastalCOMS modules

CoastalCOMS offers a range of modules relating to coastal conditions. Each module displays elements derived directly from video, raw data from climatic and other physical processes, and processed information (including predictive information) derived from this raw data. A CoastalCOMS user may select any or all modules depending on the characteristics of their location and needs.

The CoastalCOMS modules are: Vision, Wave Height, Beach Usage, Boat Usage, Shoreline Position, Beach State, Beach Risk, and Surf Quality. The Beach State, Beach Risk and Surf Quality modules are still under development.

Vision


FIG 01: Sample Vision Display
FIG 02: Sample Vision Display (From Seaway Spit, Gold Coast, Queensland)

The basic level of data access is provided through direct observation of live video. Video data is captured from a network of shore-mounted video cameras, typically mounted on surf clubs, lifeguard towers and harbour entrances. Data is archived on centralised servers either by direct ADSL connection or telemetry in more isolated areas.

A user-customisable display allows for the viewing of one or a range of locations per screen. Access to video is usually via the internet. An additional feature allows for the direct control of camera orientation and zoom.

Wave Height


FIG 03: Sample offshore Wave Height Map

This information is of great importance to all beach and ocean users, as awareness of off-shore condition assists with safety aspects of boating, along with enhanced swell and wave predictability for surfers and other beach users.

All beach users, especially surfers, would like to know the near-shore wave height on any given day and for the days ahead. Near-shore wave heights also impact beach state and beach risk.

Monitoring of the wave climate is usually conducted through the use of off-shore wave buoys. Global wave models provide effective representation of ocean wave conditions but not the transformation which occurs in near-shore areas.

Furthermore, adjacent beaches may exhibit different responses to the same off-shore wave climate. Existing near-shore wave models can simulate the transformation, but require accurate depth data.

CoastalCOMS, through the implementation of artificial neural networks, successfully generates estimates of near-shore wave height from global deep-water wave model output.

The system has already been trained on sites around Australia using two years of daily observations of wave height, and has the potential for greater coverage and detail.

The result is an automated system which updates every six hours and produces near-shore wave height forecasts for seven days in advance, including wave periods and swell direction.

FIG 04: Sample Near-Shore Wave Height Display (Produced by the artifi cial neural network)

Beach Usage


FIG 05: Sample image showing areas (black rectangles) that have been classifi ed as people.

People use beaches for fun and recreation. Monitoring beach usage is important for providing data to help predict future beach needs and to better plan human resource requirements. CoastalCOMS can measure the extent of beach usage by counting how many people are on the beach at any one time. Figure 5 (right) shows an example of an image captured from a CoastalCOMS camera.

Another important aspect of beach usage monitoring is to ascertain what people are doing on the beach. For instance: Where are people congregating? Are people walking on the beach, sunbathing, or entering the surf?

Information obtained about how people are using the beach can provide data to coastal councils and coastal management authorities to help future beach planning, and can be useful for environmental impact monitoring, surf lifesaving organisations and tourism.

Beach Statistics - Number of People

6 am

8 am

10 am

12pm

4pm

97

122

61

40

55

Average for the day:

220

Average for the month:

3214

FIG 06: Sample Beach Usage Display

Boat Usage


FIG 07: Image showing areas (black rectangles) that have been classified as boats.

People use boats for work and recreation. Monitoring boat usage is important for providing data to help predict future boating safety and support needs, to review boating behaviour, and monitor marine protected areas in real time.

CoastalCOMS measures the extent of boat usage by counting how many boats are in a particular area at any time. The image in Figure 7 is captured by a CoastalCOMS camera.

Another important aspect of boat usage monitoring is to collect data on frequency and time of usage - this can be cross-referenced against incident reporting and water conditions. This is invaluable in determining if incidents occur more in certain conditions, and enabling marine warnings to be issued in a more timely manner by marine rescue groups, councils and coastal management authorities.

Research already underway will make it possible to measure the length and type of boats accessing the harbour entrance as well.

Boat Usage

6 am

8 am

10 am

12pm

4pm

8

21

11

4

12

Average for the day:

11

Average for the month:

602

FIG 08: Sample Boat Usage display

Shoreline Position

 CoastalCOMS Shoreline example

FIG 09: Calculated shoreline indicated by red line with geo-referencing points located cross-shore in the timex image.

Global warming, and rising sea levels in particular, are now firmly on the agenda. Today many millions of dollars are spent by coastal management authorities to replenish beaches and restore shorelines throughout the world. The monitoring and maintenance of the health of a beach, and in particular the shoreline position, is of great significance to local beach users and can be of critical importance to the local economy where there is a dependence on tourism.

CoastalCOMS measures shoreline position through video images by geo-referencing the position of the water detected by the sharp contrast between dark water and bright sand to the position of the camera.This permits real-time monitoring of the shoreline position through tide cycles and storm events and assists managers in making critical decisions on beach replenishment and emergency shore protection.

Shows video captured by a CoastalCOMS camera and processed by central computer systems to calculate the position of the shoreline on the beach.

Research and development is currently underway to calculate seafloor bathymetry, measure nearshore currents, and assess rip currents. By combining bathymetry with the shoreline position we hope to be able to provide beach profiles that extend through the nearshore zone. This will provide additional information on beach volumes, a good indicator of beach health

Beach State Index


FIG 10: Sample Beach State Index display.

Beach state refers to the characteristics of the seafloor of dynamic sandy beaches. As beaches cycle through high and low wave events the sandy bed forms are shifted. The positions of bars and troughs often re-occur on timescales of weeks to months.

The most widely accepted beach state classification scheme (Wright and Short, 1984), based on longterm observation of Australian beaches, defines six regularly observed beach states.

These six beach states are:

  • Dissipative
  • Intermediate comprising of:
  • Longshore Bar and Trough
  • Rhythmic Bar and Beach
  • Transverse Bar and Rip
  • Low Tide Terrace
  • Reflective.

Analysis of video pixel intensities from Coastalwatch cameras mounted on the lifeguard tower adjacent to Narrowneck Reef at Surfers Paradise demonstrates the ability to classify beach states corresponding to the three most commonly observed intermediate beach states.

CoastalCOMS analysis of raw video data, combined with expert classifications of a long data set of beach state occurrences can identify the state of the underlying bar shapes. The state of a beach is important for addressing issues related to beach nourishment and beach risk assessment. Long-term collection of beach state data can assist with identifying beach erosion responses to extreme events and an analysis of overall safety of particular beaches.

Beach Risk Index


FIG 11: Sample Beach Risk Index display

CoastalCOMS can use expert analysis of long-term video footage of beaches, in conjunction with data from other CoastalCOMS modules, to generate a rating of beach risk. The integration of factors such as the beach state and potential variations in wave energy results in a short-term predictive capacity for risk assessment. This is of particular benefit to coastal organisations who need to effectively manage resources over large areas subject to variations in risk, and of extreme importance to all beach users.

Surf Quality


FIG 12: Sample Surf Quality display

How good is the surf today? What about tomorrow? Where is it best? Is it worth the drive?

These are important questions for many people, not only for those with a day off but for those who work to protect others and to maintain the amenity that we all enjoy while at the beach.

Coastalwatch surf reporters are busy checking the surf around Australia and around the World in the early hours of every day. This long-term data set provides a unique measure of surf quality, something difficult to define.

By training CoastalCOMS with this data and the other physical parameters CoastalCOMS records, an automated assessment and forecast of surf quality becomes possible. This has implications not only for surfers and other beach users, but for coastal councils, coastal management authorities, surf life saving organisations and lifeguards, all of whom can benefit from knowing expected numbers of beach users, and even the specific activities to expect from beach users on a given day at a particular beach.