Improving coastal dune monitoring & management – Phase 2

Cambridge Coastcare has been awarded a grant of $10,240 by Coastwest, a branch of the WA Planning Commission, for its project titled ‘Improving coastal dune monitoring & management – Phase 2’.  This project has been developed in consultation with Town of Cambridge, and with Cambridge Coastcare’s two partners in the project, Omnidrone P/L and Russell Teade. This project will build on the coastal dune monitoring data captured in 2018-19 (refer attached article) to identify trends in coastal erosion and accretion at Survey Site 1 (CMB12 to CMB14).  It will also establish a new baseline of an untreated site at Survey site 2 (CMB22) just north of Floreat Surf Life Saving Club. High resolution vegetation maps and 3D models will allow a more detailed analysis of re-vegetation success rates, sand encroachment and erosion.  

The Town of Cambridge manages a 4.5 km stretch of coastline, comprising the longest area of continuous natural coastal vegetation in Perth metro, with north Floreat Beach designated Bush Forever site #310.  Floreat beach is a wave-dominated beach subject to significant beach coastal dune erosion.  It has been designated as a Coastal Erosion Hotspot (WA Government, 2019).  One of the recommendations of the WA Government report is to “Collect information on local coastal dynamics to better understand sand movement, landform stability and shoreline response at hotspot specific scale”.

By establishing:

  # baseline data at Survey Site2 (CMB22) (over one year) and

   # comparative data over a 4 year period at Survey site1 (CMB12/14)

the project seeks to ground-truth sand movement to document the trend in erosion or accretion and vegetation success rates.  The data will quantify the effect of dune stablisation treatments.

It will accurately monitor and map dynamic elements – dune stability, vegetation cover, human impact over one year at the CMB22 site and at the CMB12/14 sites.  In addition it will document any observable trend in the dynamic elements with comparison to the 2018-19 data.

The 2018-19 aerial monitoring datasets for Floreat beach will contribute to the CHRMAP process currently underway along the coastline of the Town of Cambridge. The datasets produced during this project will update the Dept of Transport  “Capturing the coastline” data for Floreat beach.

The project meets the additional actions recommended in the Coastal Erosion Hotspots in WA including acquiring coastline movements data for hotspots, and collecting information on local coastal dynamics to better understand sand movement and landform stability.

Cambridge Coastcare (CCC) will undertake further treatments at CMB12 – lateral fencing, hessian matting and planting.  Note the other 2 sites – CMB14 and CMB 22 will remain untreated to determine the effect of natural sand movement and natural vegetation success rates.

Cambridge Coastcare’s 2 partners will undertake the monitoring work:

  1. OmniDrone Pty Ltd will undertake the 2 aerial survey flights at the 3 locations: CMB12, CMB14 and CMB22 (a) aerial flight 1 in winter (August 2021) and (b) aerial flight 2 in autumn (May 2022).   Each aerial survey consists of 3 flights to each location – 1 flight looking directly down, 2 flights from each direction at a camera angle of 30 degrees. 
  2. Russell Teade (Project Spatial Analyst) will undertake the data analysis to include 2D orthomosaics for 2D change detection (plant growth, sand encroachment) and 3D models for volumetric measurements and change detection (sand erosion/encroachment).

The resulting high quality photographs, video animations and spatial outputs will be made available to all stakeholders – Town of Cambridge, WA Government agencies, SWALSC and the community.  In addition, it is proposed to establish a YouTube site with the video animations of both survey sites to facilitate easier access for the community.