Establishing the characteristics, distribution and origin of Quaternary sediments and associated landforms provides valuable data for understanding spatial and temporal variations in earth-surface processes, while being fundamental to natural resources management, infrastructure planning and environmental protection. Over much of Canada, regional Quaternary mapping has been led by geological surveys and academia, which have typically produced small scale maps that primarily meet the needs of the mineral exploration industry and regional land use planning. However, many projects increasingly require more detailed surficial geological information for infrastructure development and geohazard identification. Furthermore, the establishment of glacial geological inversion models as a tool to reconstruct variations in the configuration and flow geometry of Quaternary ice sheets requires increasingly detailed analysis of the distribution and stratigraphic context of a range of subglacial landforms. Such analysis necessitates the synthesis of large amounts of geological information from interpreted aerial photographs, remote sensing images, and fieldwork observations processed in a multi-layered GIS environment.
The main limiting factor in previous surficial mapping approaches has been the inability to accurately delineate landforms from aerial photographs or satellite-based digital elevation models (DEMs), particularly in regions with extensive forest cover. However, the increasing availability of high-resolution LiDAR data is resulting in a wealth of new opportunities. When used in concert with optical and radar remote sensing imagery, LiDAR has emerged as a fundamental tool for detailed surficial geology mapping, which in turn benefits exploration, engineering and environmental applications. The integration of multiple remote sensing technologies provides a more complete view of the landscape, enables efficient, ‘heads-up’ digitization, and facilitates the use of quantitative, predictive methods for rapid large scale mapping through systematic landform characterization.
In Alberta, recent surficial geology mapping utilizing LiDAR bare-earth imagery reveals widespread and complex suites of previously unidentified glaciogenic landforms relating to the advance and retreat of the Laurentide and Cordilleran ice sheets. Such landforms demonstrate that the dynamics and subglacial thermal regimes of these ice sheets were more complex than has been previously identified from DEM or aerial photograph mapping.