Figure 1 . Challenges of estimating the steepness of the
intertidal zone in a dynamic coastal environment where the beach face is
constantly fluctuating landwards/seawards due to erosion/accretion
processes. Red dots indicate long-term satellite-derived shoreline
measurements (x coordinate) sampled at various tidal elevations (y
coordinate). a) Hypothetical example of a static beach profile
where the cross-shore variations in the water line are entirely due to
the rise and fall of the tide and therefore the intertidal beach profile
can be accurately reconstructed. b) Real-world example of a
surveyed profile at Narrabeen Beach (Australia) where the continuous
erosion and accretion of the beach results in scattered observations
from which it is not possible to reconstruct the intertidal beach
profile.
2 Materials and Methods