Canadian Forest Service Publications

Digital image analysis techniques on an IBM microcomputer for measuring soil disturbance following timber harvesting. 1992. Lee, Y.J. Pages 158-165 in G. Greer, Editor. Remote sensing and natural resource management, Proceedings: 4th Forest Service Remote Applications Conference. April 6-11, 1992, Orlando, Florida. American Society for Photogrammetry and Remote Sensing, Bethesda, MD.

Year: 1992

Issued by: Pacific Forestry Centre

Catalog ID: 3266

Language: English

Availability: Order paper copy (free)

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Abstract

This technique is a novel approach for solving a practical forestry problem. A semi-automatic image processing procedure, combining computer digitization and digital analysis of aerial photographs, was employed to quantify soil disturbance following timber harvesting. Soil disturbance levels are difficult and time-consuming to delineate using conventional ground surveys. However, disturbance resulting from construction of landings, haul roads, skid trails and fireguards can be easily calculated from the manually traced pixels. In addition, two levels of disturbance, which correspond to "Class A" (deeply displaced mineral soil) and "Class B" (shallowly displaced mineral soil) can be consistently isolated using contrast stretching and threshold classification techniques. These two levels of disturbance could be used to determine the maximum allowable disturbance levels based on site sensitivity under the British Columbia Ministry of Forests (BCMF) Interim Harvesting Guidelines and Silviculture Regulations. This processing can be completed by one person within 2 to 3 hours, compared to one or two days for 2 persons to complete a ground survey of a cutblock.