Mapping Riparian Zones over Large Regions from High Spatial Resolution Satellite and Airborne Imagery: Specifications for Operational Mapping

Riparian zones maintain water quality, support multiple geomorphic processes, contain significant biodiversity and also maintain the aesthetics of the landscape. Australian state and national government agencies responsible for managing riparian zones are planning missions for acquiring remotely sensed data covering the main streams in Victoria, New South Wales, and parts of Queensland and South Australia. The work presented in this paper provides proof-of-concept and operational specifications for using commercially available high spatial resolution satellite and airborne image datasets to map riparian condition indicators. The objectives of this paper are to: (1) assess the ability of different high spatial resolution image datasets for mapping the environmental condition of riparian zones in four distinct environments in Australia; and (2) provide specifications for capturing and analyzing the data most suited for riparian zone mapping at large spatial extents (> 1000 km of stream length). LiDAR derived digital elevation models, terrain slope, intensity, fractional cover counts and canopy height models were used to map riparian condition indicators using simple algorithms and more complex object-oriented image analysis. The results showed that LiDAR data are most suitable for mapping riparian condition indicators: water bodies; streambed width; bank-full width; riparian zone width; width of vegetation; plant projective cover; longitudinal continuity; vegetation height classes; large trees; vegetation overhang; and bank stability. Results of this work will contribute to future riparian zone mapping in Victoria, New South Wales, and parts of Queensland and South Australia.