The land surface is the natural context for life on Earth. Life depends on Earth surface processes over a wide range of space and time scales. It is thus not surprising that models of the land surface of the Earth have played an integral role in Geographic Information Science since its inception. Analyses and representations of the land surface have directly stimulated new methods for obtaining digital environmental data, new spatial interpolation methods and new methods for analysing landscape dependent hydrological and ecological processes. Of central importance for environmental modelling is the accuracy and spatial coverage that can be achieved by incorporating appropriate dependencies on the land surface.
This lecture describes the speaker’s experiences in generating and applying regular grid digital elevation models to support the elevation and landscape shape requirements of environmental modelling over a range of spatial scales. The methods have evolved over time as topographic data sources have moved from relatively sparse, accurately surveyed, point and line data to the dense, but noisy, data typically provided by remote sensing platforms. An essential shape-based requirement for hydrological applications is drainage connectivity. The process of achieving this on fine scale SRTM data by coupling data smoothing and automated drainage enforcement is described. It has involved a technically demanding interplay between input drainage data quality and algorithmic development. The hydrologically enforced SRTM data underpin the Australian Hydrological Geospatial Fabric (Geofabric) being developed by the Fenner School for the Bureau of Meteorology in collaboration with CSIRO Water for a Healthy Country Flagship and Gesoscience Australia.
About the Speaker
Michael Hutchinson is Professor of Spatial and Temporal Analysis at the ANU Fenner School of Environment and Society. His methods for modelling of climate and terrain, as implemented in the ANUDEM, ANUSPLIN and ANUCLIM software, are widely used to support hydrological and ecological modelling and the assessment of the impacts of climate change. His Australia-wide terrain and climate models have underpinned much of the natural resource and environmental analysis carried out by Australian Universities and Natural Resource Agencies over the last 25 years.