A GIS EXPERT SYSTEM FOR THE DELINEATION OF WATERSHEDS IN LOW- RELIEF REGIONS WITH RURAL INFRASTRUCTURE

Grid-based digital elevation models (DEMs) are used to simulate overland flow paths in hydrological models. The accuracy of these drainage patterns are dependent upon how well the DEM represents the terrain features that control runoff patterns. Often regional DEMs are not produced at scales small enough to represent rural infrastructure. The scale of runoff patterns that can be accurately modeled is, therefore, restricted, particularly when the terrain is relatively flat. The RIDEM (Rural Infrastructure Digital Elevation Model) model is presented that utilizes commonly available ancillary data to downscale grid-based runoff patterns. The resulting drainage patterns reflect drainage modifications imposed by rural infrastructure including: roads, ditches, culverts, and irrigation canals. Downscaling runoff patterns enables the completion of runoff studies at smaller scales. The model was implemented within the Oldman River watershed, Alberta, Canada to determine the spatial patterns of potential runoff contributing areas in three agricultural watersheds regularly contaminated by pathogens. ii Acknowledgements I would like to extend my appreciation to Dr. Stefan Kienzle for giving me the opportunity to expand my horizons and for his support, expertise, and encouragement during this process. Thanks are also due to Dr. Dan Johnson, Dr. Jim Byrne, and Dr. Alain Pietroniro for their efforts. Extra thanks are owing to Dan Johnson for his contributions to the field component of this research and his diligent editorial critiques. This opportunity would not have been realized if not for the funding by the Nationa