Tree crown porosity estimation method based on porous medium theory and computer graphics

Abstract

The invention discloses a tree crown porosity estimation method based on a porous medium theory and computer graphics. The method comprises the following steps: collecting tree laser point cloud data; performing point cloud classification on the leaves and the branches, fitting the branches through a cylinder with adaptive radius distribution, and extracting point cloud data of a single leaf; performing de-noising processing on the point cloud data of the single leaf; determining edge points of each blade by adopting a cubic polynomial curve fitting method; calculating the equivalent thickness of each blade, and enveloping the point cloud of each blade through a hexagonal prism formed by self-adaptive parameter distribution to obtain the equivalent volume of each blade; and calculating the total equivalent volume of all the leaves and the total volume of all the branches in the crown, and estimating the porosity of the crown by combining the volume of the crown. The GF global solution obtained by the method does not change along with the change of the observation visual angle, the limitation of generating local data of the HP through projection transformation is overcome, and the limited visual coverage of other information is omitted from a fixed position.

Description

technical field [0001] The invention belongs to the technical field of crown porosity analysis, in particular to a tree crown porosity estimation method based on porous medium theory and computer graphics. Background technique [0002] Canopy porosity (GF), also known as canopy porosity, is important for characterizing forest habitats. GF is not only a key parameter for accurate quantification of leaf area index (LAI), but also an important factor for better understanding of plant-environment exchange processes, such as photosynthesis, plant transpiration efficiency, and canopy rainfall interception. The lack of air movement in the plant canopy produces a wetter microclimate, but the increased GF favors air movement within the canopy, which ensures that leaf elements within the canopy are exposed to solar radiation, reducing light conditions. Poorly shaded areas prevent the occurrence of fungal infections within the forest canopy. In addition, GF can be used as a biologica...

Images