Reference Document - Coastal Hazard Assessment - MCU24 0094 · MCU24/0094

                              33 Ross Crescent, Sunshine Beach – Coastal Hazzard Assessment | 33 Ross Crescent Family Trust




Figure 3-8 November 2018 Aerial Photograph

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 3-9 to Figure 3-11.




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