The goal of this lab was to learn to learn to calculate vegetation statistics using LiDAR data.
METHODS
First, LP360 was used to create a DTM for the canopy height of the study area. This was done by creating DTM images for both the canopy surface, using first return vegetation points, and ground surface, using last return ground points. A raster calculator was then used to subtract the canopy height from the ground to create a vegetation canopy height raster. There were some negative values in the data from error, and were selected and removed for further calculations.
Next, above ground biomass (AGB) was calculated using model builder in ArcMap. This was done by separating vegetation by species in the study area because species have different parameters for calculations.
This data was then used to calculate the breakdown of the AGB for each species based on stem, branch, and foliage mass. This was done by calculating percentages of each of these based on species and multiplying this by the previously found AGB.
RESULTS
A graph of distributions in vegetation height is shown below.
The canopy height raster is shown below. Negative values are indicated by black symbology.
The AGB map for the entire area is shown below. The species are marked with different colors. The black areas were non-vegetated areas.
Maps for the three parameters: stem, branch, and foliage mass are shown below.
The model created to find the AGB is shown below, followed by a section of the model showing the steps for a single species.
SOURCES
Data obtained from Cyril Wilson for use in 358 LiDAR course.
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