Preliminary Recommendations for Mapping of Aquatic Habitat Parameters for the AOSERP Study Area

Three aspects of aquatic habitat assessment and mapping have been considered. The first aspect was the review of the parameters which characterize aquatic habitats in the AOSERP study area. From an extensive list, ten parameters for each of lake habitats and river habitats were selected as being of greatest significance. Those in common to lakes and rivers include: dominant fish species, dominant invertebrate groups, maximum temperature, minimum oxygen, substrate codominants and turbidity. Those characteristic of rivers only are rooted width, gradient, and velocity, while those characteristic of lakes only are maximum depth, percent littoral area, and percent surface area occupied by aquatic macrophytes. An efficient procedure for collecting the data pertaining to those parameters over a large area is recommended. This procedure includes: a watershed coding system, remote sensing analysis, preliminary mapping, helicopter surveys, and ground sampling programs. Finally, a key was developed for mapping the aquatic habitat parameters at a scale of 1:50,000. The second aspect was the review of the application of remote sensing data to the interpretation and assessment of aquatic habitats. This applicability of several sensors, such as black and white panchromatic, colour, colour IR, black and white IR, thermal IR, SLAR, multispectral sensors, and LANDSAT sensors, to the assessment of aquatic habitat parameters is presented. The properties which are most readily distinguished are illustrated with representative photographs. The technical considerations which must be made when planning a remote sensing data gathering mission are discussed. These factors include film and filter combinations, altitudes, time of day, time of year, and other considerations. The third aspect was the review of the state of the art in computerized mapping techniques. This review includes levels of data processing and their application, the data encoding processes, map creation and presentation, and user competence requirements. It is recommended that a detailed comparative review of three of the most advanced computerized mapping systems be undertaken. The application of computerized mapping to AOSERP must be carefully assessed, and should be undertaken only if all resource and land management data for the study area are to be included in the project.