Beach foreshore slope for the West Coast of the United States (ver. 1.1, September 2024)

This data release contains foreshore slopes for primarily open-ocean sandy beaches along the west coast of the United States (California, Oregon and Washington). The slopes were calculated while extracting shoreline position from lidar point cloud data collected between 2002 and 2011. The shoreline positions have been previously published, but the slopes have not. A reference baseline was defined and then evenly-spaced cross-shore beach transects were created. Then all data points within 1 meter of each transect were associated with each transect. Next, it was determined which points were one the foreshore, and then a linear regression was fit through the foreshore points. Beach slope was defined as the slope of the regression. Finally, the regression was evaluated at the elevation of Mean High Water (MHW) to yield the location of the shoreline. In some areas there was more than one lidar survey available; in these areas the slopes from each survey are provided. The child page "Beach foreshore slope for the West Coast of the United States" contains the slope data. The child page "Reference baselines used to extract shorelines for the West Coast of the United States" contains information about the reference baseline, the cross-shore transects and the Mean High Water values used to calculate the shoreline position.