Description and classification of generic landforms: from words to concepts for digital use and decision support

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In this last decade, the focus in geomatics engineering has shifted from computational issues looking at performance and accuracy to decisional issues where the objective is to be able to make decisions from the information available. Software applications are supposed to retrieve and process data at a semantic level to make their own decisions or to assist a user in making an informed decision. In order to reason, spatial entities are perceived as objects with their own spatial and semantic properties and relationships.***Little interest has been devoted to terrain description, one of the most often found spatial data but which is not modelled as an object. Most processes are able to classify terrain data according to some mathematical descriptors such as the slope but they cannot classify landforms. Indeed, landforms such as a mountain or a valley have subjective and vague definitions which vary with individuals. Providing a formal definition that can be processed in a computing system is a difficult task. Landform terminologies remain too implicit to be handled and processed for terrain data classification. Such a work requires the definition of a whole framework which formalises landform description 1) at a conceptual level where an abstract definition approved by domain experts is given, 2) at a logical level where the definition is translated into object-oriented concepts for implementation, and 3), at a communication level for data visualisation and exchange.***This research programme therefore proposes a conceptual framework where landforms can be defined from a formal conceptual model to a model that allows landform recognition on a digital terrain model (DTM). The framework is built around the principle that landforms are not characterised by geometrical attributes but by salient features structuring the terrain. Three objectives are identified for this five-year programme:***1. To conceive a generic conceptual model from which landform concepts can be derived;***2. To translate the conceptual model into a logical model where salient features can be extracted from a DTM;***3. To demonstrate the applicability of the approach through two applications: 1) an application automating nautical chart production and 2) a Web service for online extraction of landforms for general purpose.***Several deliverables are anticipated at both conceptual and applied research levels:***- a prototype providing a conceptual model for landform description based on saliencies***- a set of algorithms and structures for landform extraction from a DTM***- a prototype system for automatic undersea feature classification in chart production***- a system architecture for a Web service for landform analysis***Both systems will be applied to geomorphological studies of coastal areas of Canada. It is expected that the programme will contribute to a better understanding of environmental phenomena in maritime areas of Canada.********