Long-term observational datasets that record and quantify variability, changes and trends in beach morphology at sandy coastlines together with the accompanying wave climate are rare. A monthly beach profile survey program commenced in April 1976 at Narrabeen located on Sydney’s Northern Beaches in southeast Australia is one of just a handful of sites worldwide where on-going and uninterrupted beach monitoring now spans multiple decades. With the Narrabeen survey program reaching its 40-year milestone in April 2016, it is timely that free and unrestricted use of these data be facilitated to support the next advances in beach erosion-recovery modelling. The archived dataset detailed here includes the monthly subaerial profiles, available bathymetry for each survey transect extending seawards to 20 m water depth, and time-series of ocean astronomical tide and inshore wave forcing at 10 m water depths, the latter corresponding to the location of individual survey transects. In addition, on-going access to the results of the continuing monthly survey program is described.
Narrabeen Profiles
The pre-2005 survey measurements (survey method ‘EMERY’ in column 5) were undertaken at a fixed cross-shore spacing of 10 m (no interpolation), while surveys undertaken after this time (survey method ‘GPS’) have been interpolated to a standard 1 m cross-shore spacing. Intermittent survey measurements in the stable dune areas of each profile have been carried through to the following survey date and are identified by the flag ‘DUNEFILL’ in column 5. Elevation is relative to Australian Height Datum (AHD), corresponding to approximately mean sea level. Lat/long are referenced to GRS80 Ellipsoid. Refer to ReadMe file for site description, individual transect locations and full details of data file content and format.
Narrabeen_Profiles.csv
Narrabeen Bathymetry
Cross-shore bathymetry transects to accompany the historical profile surveys have been obtained from 11 hydrographic surveys conducted by the NSW Office of Environment and Heritage (OEH) during the period 2011 - 2015. These hydrographic surveys have been undertaken using a variety of methods: a single-beam jetski-mounted system for shallow water depth soundings (8 jetski surveys in total); a single-beam boat-mounted system for shallow-intermediate water depth soundings (2 surveys); and a multi-beam boat-mounted system for intermediate water depth soundings at high resolution (1 survey). Refer to ReadMe file for full description of file format.
Narrabeen_Bathymetry.csv
Narrabeen Inshore Waves
Hourly time-series of inshore significant wave height (Hs), peak wave period (Tp) and wave direction (Dir) at 10 m water depth directly seaward of each of the 5 beach profile survey transects. The combined measured/hindcast time-series was transformed to these five specific locations using the nearshore wave model SWAN. Refer to the ReadMe file for full descriptions of the data sources, transformation and file format.
Narrabeen_Inshore_Waves.csv
Narrabeen Astronomical Tide
Astronomical Tides over the same time period as the combined wave data (i.e., January 1979 – October 2014) have been derived at 15 minute intervals using the T_Tide tidal analysis package based on available water-level data (1987 and 2012) at the nearby HMAS Penguin tide gauge. Absolute tidal anomalies due to short-term atmospheric and oceanographic fluctuations based on this tidal analysis are found to be limited to 0.19 m for 95% of the time and 0.26 m for 99% of the time. Refer ReadMe file for details of file format.
Narrabeen_Astronomical_Tide.csv
