Evaluation of arid land systems using airborne video

Abstract

This paper reports trials utilizing an airborne video system at different wavelengths and spatial resolutions in a range of arid land systems. We aimed to evaluate the range of arid landscape features discernible with airborne video and to assess whether the video may have a role as an adjunct to ground measurements for interpretation of satellite imagery. Low level colour visible airborne video images provided good discrimination of trees and perennial shrubs, while higher level visible and infra‐red images allowed clear mapping of landscape elements such as ground cover mosaics, erosional features and drainage lines. Significant correlations were developed between ground and image estimates of tree, perennial shrub and ground cover, and bare ground, although the interpretation of the video images considerably over‐estimated the plant components. Smaller ground cover components such as grasses, ephemeral plants and surface stone could not be discriminated at the resolution of the video imagery, unless present as significant aggregations, with the result that image estimates of their abundance were poor predictors of ground measured proportions. However, both the moving video and captured images provided a good record of fine scale ground cover patterns often not visible to the ground observer, which could help to interpret the broader land systems apparent in satellite imagery.