Design With Nature 2.0 – A Geodata Infrastructure Approach to Map Overlay

McHarg's "Design With Nature" was a precursor of the layer model in modern geographic information systems. We are reviewing the layer overlay approach from a geospatial data infrastructure (GDI) perspective and experiment with weighted map overlay using Web map services. A case study for natural hazard risk assessment for Southern Quebec illustrates this visual approach to multi-criteria analysis using online mapping. We conclude with a call for more research on thematic mapping and its use for decision support within GDIs.