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 dataset is described in Vos et al. 2021, "Beach-face slopes dataset for Australia".

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). 

The coordinate system for both geospatial layers is EPSG:3112 - GDA94 / Geoscience Australia Lambert - Projected.

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:
  - Beach-face Slope: Estimate of the beach-face slope between Mean Sea Level (MSL) and Mean High Water Springs (MHWS)
  - Lower Confidence Bound: Lower limit of the confidence band for the slope estimate
  - Upper Confidence Bound: Upper limit of the confidence band for the slope estimate
  - Width of Confidence Band: Width of confidence band (between 0 and 0.19)
  - Upper Confidence Bound: Upper limit of the confidence band for the slope estimate
  - Confidence Flag: Quality flag indicating the confidence in the slope estimate at this transect (High, Medium or Low)
  - Number of Shoreline Points: Number of datapoints in the time-series used for beach-face slope estimation (minimum 100)
  - 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
  - Coastal Region: Database id corresponding to the 23 coastal regions as identified by Thom et al. (2018)
  - Primary Sediment Compartment: Database id corresponding to the 100 primary sediment compartments as identified by Thom et al. (2018)
  - Secondary Sediment Compartment: 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:
  - Average Beach-face Slope: Average of the beach-face slope at the site, weighted by the width of the confidence bands
  - Average Width of Confidence Bands: Average width of confidence band over the comprised transects
  - Confidence Flag: Quality flag indicating the confidence in the slope estimate at this transect (High, Medium or Low)
  - Average Number of Shoreline Points: Average number of datapoints in the time-series over the comprised transects
  - beach_id: Database id for each beach, e.g., aus0001, aus0002, …, aus5255
  - Coastal Region: Database id corresponding to the 23 coastal regions as identified by Thom et al. (2018)
  - Primary Sediment Compartment: Database id corresponding to the 100 primary sediment compartments as identified by Thom et al. (2018)
  - Secondary Sediment Compartment: 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, ...
  - Average Beach-face Slope (by beach): Average beach-face slope in each coastal region, averaged across all the individual beaches inside the polygon
  - Average Beach-face Slope (by transect): Average beach-face slope in each coastal region, averaged across all the individual 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 Sediment Compartment id: Database id corresponding to the 100 primary sediment compartments as identified by Thom et al. (2018)
  - name: name of each primary sediment compartment
  - Average Beach-face Slope (by beach): Average beach-face slope in each sediment compartment, averaged across all the individual beaches inside the polygon
  - Average Beach-face Slope (by transect): Average beach-face slope in each sediment compartment, averaged across all the individual 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 Sediment Compartment id: Database id corresponding to the 361 secondary sediment compartments as identified by Thom et al. (2018)
  - name: name of each secondary sediment compartment
  - Average Beach-face Slope (by beach): Average beach-face slope in each sediment compartment, averaged across all the individual beaches inside the polygon
  - Average Beach-face Slope (by transect): Average beach-face slope in each sediment compartment, averaged across all the individual transects inside the polygon