Beach-face slope dataset for Australia

This repository contains a dataset of beach-face slopes for the Australian coastline. It includes more than 13,200 km of sandy coast with estimates of the beach-face slopes provided every 100 m. The methodology and dataset are described in:

Vos, K., Deng, W., Harley, M. D., Turner, I. L., and Splinter, K. D. M.: Beach-face slope dataset for Australia, Earth Syst. Sci. Data, 14, 1345–1357, https://doi.org/10.5194/essd-14-1345-2022, 2022.

The beach-face slope data is provided in 2 separate GEOJSON files: Australia_slopes_by_transect.geojson and Australia_slopes_by_beach.geojson. The first one presents the data along each transect (total of 132,132 beach transects) and the second one presents the data for each individual beach/embayment (total of 5,207 beaches).  Additionally, there are three layers that contain polygons for the Australian coastal regions, primary compartments and secondary compartments, respectively.

The coordinate system for the geospatial layers is WGS84.

1. Australia_slope_by_transect.geojson: contains a geospatial layer with cross-shore transects along the Australian sandy coastline. Each feature in this layer is a transect (2 point linestring) with the following attributes:
  - transect_id: Database id for each transect, e.g., aus0001-0000, aus0001-0001, …
  - beach_id: Database id for each beach, e.g., aus0001, aus0002, …, aus5255
  - beach_slope: estimate of the beach-face slope between Mean Sea Level (MSL) and Mean High Water Springs (MHWS), value between 0.01 and 0.2
  - lower_conf_bound: Lower limit of the confidence band for the slope estimate
  - upper_conf_bound: Upper limit of the confidence band for the slope estimate
  - width_conf_band: Width of confidence band, value between 0 and 0.19)
  - sl_points: Number of datapoints in the shoreline time-series used for beach-face slope estimation (minimum set to 100)
  - quality_flag: Quality flag indicating the confidence in the slope estimate at this transect (High, Medium or Low)
  - coastal_region: Database id corresponding to the 23 coastal regions as identified by Thom et al. (2018)
  - primary_comp_id: Database id corresponding to the 100 primary sediment compartments as identified by Thom et al. (2018)
  - secondary_comp_id: Database id corresponding  to the 361 secondary sediment Compartments as identified by Thom et al. (2018)

2. Australia_slope_by_beach.geojson: contains a geospatial layer with each individual beach/embayment (as a linestring) along the Australian sandy coastline. Each feature has the following attributes:
  - beach_id: Database id for each beach, e.g., aus0001, aus0002, …, aus5255
  - beach_slope_average: Average of the beach-face slope at the site, weighted by the width of the confidence bands, value between 0.01 and 0.2
  - width_ci_average: Average width of confidence band over the comprised transects, value between 0 and 0.19
  - quality_flag: Quality flag indicating the confidence in the slope estimate at this transect (High, Medium or Low)
  - mstr: Mean Spring Tide Range at the beach calculated from the closest grid point in the FES2014 global tide model
  - hsig_median: Median Significant Wave Height from the closest grid point in the CAWCR re-analysis dataset
  - prc_msrt_obs: percentage of the Mean Spring Tide Range observed by the satellite-derived shorelines
  - min_tide_obs: Lowest tide level observed by the satellite-derived shorelines
  - max_tide_obs: Highest tide level observed by the satellite-derived shorelines
  - sl_points_average: Average number of datapoints in the shoreline time-series over the comprised transects
  - beach_length: Length of the beach or embayment, very long beaches (>50km) were split to optimise memory usage when downloading the satellite images
  - coastal_region: Database id corresponding to the 23 coastal regions as identified by Thom et al. (2018)
  - primary_comp_id: Database id corresponding to the 100 primary sediment compartments as identified by Thom et al. (2018)
  - secondary_comp_id: Database id corresponding  to the 361 secondary sediment Compartments as identified by Thom et al. (2018)

In addition to these two layers, the 3 different levels of the Sediment Compartments framework (Thom et al.. 2018) with their average beach-face slopes are also included here.

3. coastal_regions.geojson: contains a geospatial layer of each coastal region (as polygon) as defined by Thom et al. 2018. Each feature has the following attributes:
  - name: name of the coastal region, e.g., Pilbara, Kimberley, etc
  - beach_slope_average_by_beach: Beach-face slope in each coastal region averaged across all the individual beaches inside the polygon
  - beach_slope_average_by_transect: Beach-face slope in each coastal region, averaged across all the individual 100-m spaced transects inside the polygon

4. primary_compartments.geojson: contains a geospatial layer of each primary sediment compartment (as polygon) as defined by Thom et al. 2018. Each feature has the following attributes:
  - primary_comp_id: Database id corresponding to the 100 primary sediment compartments as identified by Thom et al. (2018)
  - name: name of each primary sediment compartment
  - beach_slope_average_by_beach: Beach-face slope in each coastal region averaged across all the individual beaches inside the polygon
  - beach_slope_average_by_transect: Beach-face slope in each coastal region, averaged across all the individual 100-m spaced transects inside the polygon

5. secondary_compartments.geojson: contains a geospatial layer of each secondary sediment compartment (as polygon) as defined by Thom et al. 2018. Each feature has the following attributes:
  - secondary_comp_id: Database id corresponding to the 361 secondary sediment compartments as identified by Thom et al. (2018)
  - name: name of each secondary sediment compartment
  - beach_slope_average_by_beach: Beach-face slope in each coastal region averaged across all the individual beaches inside the polygon
  - beach_slope_average_by_transect: Beach-face slope in each coastal region, averaged across all the individual 100-m spaced transects inside the polygon