ECM_22343537_v1_Coastal Hazard Assessment · 132000.200173.1

                                                              Internal use only




              Figure 9 2017 Aerial Photograph (qimagery.information.qld.gov.au


              3.1         Satellite Imagery
              Satellite imagery can be used to determine shoreline position and behaviour from 30+ years of satellite
              imagery. Satellite platforms include Landsat 5 (1984 - 2013), 7 (1999 - present), 8 (2013 - present) and
              Sentinel-2 (2015 - present), with pixel resolution ranging between 10m and 15m and image capture
              varying from 5 to 16 days.

              Two independent tools have been developed to analyse the satellite imagery, which are:

                   1. CoastSat a Python tool that enables extraction of shoreline position from individual satellite
                      images at any coastline worldwide using sub-pixel extraction methods (Vos et al., 2019a, 2019b).
                      While the horizontal errors for detected shoreline range have been reported to be between 7.3m
                      and 12.7m Root Mean Square Error (RMSE) considering individual images, the bias of the data is
                      much lower (Vos et al., 2019a). As such, the temporal resolution of the data means that signals
                      can be discerned at seasonal and greater timescales.

                   2. Digital Earth Australia (DEA) is a tool to accurately map the boundary between land and water
                      (the ‘waterline’) (Bishop-Taylor et al, 2019). The tool uses the same sub-pixel extraction method
                      as CoastSat. However, DEA combines aerials to provide a single, annualised shoreline position
                      and is therefore suited to determining long-term trends.

              Outputs from both CoastSat and DEA are available online, with key outputs for the coastline adjacent to
              the site are provided in Figure 10 to Figure 12.

              13 February 2023         2 ARAKOON CRESCENT, SUNSHINE BEACH                         PA3303      13


Document Set ID: 22343537
Version: 1, Version Date: 16/03/2023