glassfire {lacunr}

California oak forest stand before and after 2020 Glass Fire

Description

This dataset contains point cloud data from two terrestrial LiDAR scans of a Northern California oak forest shortly before and after the Glass Fire, which burned some 27000 hectares of land in Sonoma and Napa counties between September 27 and October 20, 2020. The scans encompass an identical 24m by 24m rectangular plot at a study site within the Saddle Mountain Open Space Preserve in Sonoma County.

Usage

glassfire

Format

A data table with 1,000,000 rows and 4 columns: X, Y, Z, and Year

X,Y,Z

The XYZ spatial positions of each point, in meters. X and Y denote the East-West and North-South horizontal positions, respectively, while Z denotes the vertical position

Year

The year each LiDAR scan was taken, either 2020, immediately before the Glass Fire, or 2021, a few months after

Details

The original terrain topography has been removed using digital elevation model (DEM)-based height normalization, and ground points removed by clipping all points below 0.25m. The raw point cloud data were normalized via voxelization at a resolution of 0.125m, and the results further down-sampled to make the dataset more compact. The X, Y, and Z coordinates were generated from the original Easting, Northing, and elevation by subtracting their minimum values.

glassfire is technically encoded as a lasmetrics3d object from the lidR package. This class inherits from data.table(), but has the added benefit that it can be rendered as a 3D rgl plot using lidR::plot.lasmetrics3d().