Beach slopes from satellite-derived shorelines

A global analysis of extreme coastal water levels with implications for potential coastal overtopping

“…On the other hand, accurate measurements of global coastal morphological evolution and subsidence trends are still to be done despite promising local to regional emerging satellite techniques [55][56][57] . In the near future, an advanced approach such as that presented by Vos et al 58 to reconstruct foreshore slope from satellite-derived shoreline tracking and tide level could be applied globally. The global scale of the analysis presented here thus necessitates some simplifications in estimating ECWL, particularly in calculating wave runup using Stockdon et al's 32 empirical formulae.…”

Large regional variability in coastal erosion caused by ENSO

“…The CoastSat toolbox 29 was then used to automatically map the shoreline position on Landsat 5 (1984Landsat 5 ( -2013, Landsat 7 (1999-current) and Landsat 8 (2013-current) images. The resulting time-series of shoreline change were tidally-corrected using a global tide model and a satellitederived estimate of the average beach slope 28 , amounting to 72,000 beach transects in total across the Paci c.…”

“…While this approach has been successfully used to identify global long-term trends in shoreline change over several decades 1,27 , a major factor that has to-date limited the temporal resolution of satellite-derived coastal observations (including interannual variability) has been the effect of high-frequency tidal uctuations, requiring the use of satellite composite images averaged over large temporal windows (i.e., annually). However, novel methods for beach slope estimation and tidal correction at the global scale 28 now make it possible to map shoreline changes using individual satellite images (typically every 15 days for Landsat), signi cantly increasing the frequency of satellite-derived coastal data.…”

Beach Morphology and its Dynamism from Remote Sensing for Coastal Management Support

“…The approach followed in this study estimates grain size from shoreline changes, a relationship that is conditioned by the beach slope. In relation with that but following a different methodology Vos et al (2020) have recently proposed the employment of time series of SDS to quantify the slope of the beach by frequency domain analysis, reaching high correlations with the validation data. Both works serve to illustrate the significant correlation between sediment size, slope and shoreline variability.…”

“…For the moment, SDS have barely been used to obtain information about other geomorphological aspects of the beach. Only very recently, Vos et al (2020) have exploited the relation between shoreline changes and beach-face slope by estimating the latter one from SDS by frequency domain analysis. Considering the forehead stated relationship between grain size and beach-face slope, it is expected that beaches with coarser material and steeper slopes will show lower shoreline variabilities.…”