4DM completes project to develop algorithms for near – real time flood extent and depth from RADARSAT-2 and LiDAR

4DM, in collaboration with C-Core, recently completed a project on the development of algorithms and software tools to support near real-time mapping of flooding, commissioned by Natural Resources Canada’s Emergency Geomatics Services (EGS). The objectives of the project were to (1) improve the accuracy of flood extent mapping by complementing an existing EGS open-water detection algorithm with specialized approaches for vegetated and urban areas and a GIS-based conflation post-processing, and (2) enable calculation of flood depth within the inundated area.

Within the scope of this project 4DM has developed an algorithm and a software toolset for performing conflation post-processing of remotely-sensed flood extent areas (open-water only, as well as combined with specialized vegetated/urban algorithms) to ensure the hydrologic validity of the resulting flood extent, and for determination of flood depth. 4DM also conducted research for the urban flood detection algorithm.

Preliminary results from the Richelieu and Red rivers indicate that the conflation post-processor significantly improves the accuracy of flood extent mapping in comparison to the existing open-water algorithm in areas where the flow pattern is primarily 1-D (well defined valleys) and high-resolution DEM is available. The approach currently does not perform as well in flat terrain where flow patterns are more 2-D in nature and/or DEM quality is lower.

4DM awarded contract for the development of a National Guide on the Acquistion of Airborne LiDAR Data

We are pleased to announce that 4DM has been contracted to coordinate the development of a National Guide on the Acquisition of Airborne LiDAR Data. Airborne LiDAR has become or is becoming a primary source of elevation data for applications in flood risk mapping, infrastructure mapping, forestry, and for assembling nationwide topographic dataset across Canada. Over the years various LiDAR actors in Canada have developed their own standards and specifications for data acquisition. The absence of common national guidelines often leads to lack of uniformity in collected data, which becomes especially apparent when integrating data across jurisdictions or projects.

The goal of the project, awarded by the Canadian Centre for Mapping and Earth Observation (CCMEO) of Natural Resources Canada, is to update, revise and finalize the current draft National Guidelines by leveraging the standards, specifications, guidelines and best practices for acquisition of airborne LiDAR data available in Canada and internationally. Our vision for developing the LiDAR guidelines is to provide a primary reference source for governments, commercial organizations, NGOs and researchers involved in the planning, acquisition, and use of airborne LiDAR data, thus facilitating a more harmonized and standardized approach for acquiring LiDAR datasets across the country. It is envisioned that the Guidelines will contain common industry-neutral specifications, while considering unique requirements for different vertical application areas, such as forestry, floodplain or coastal zone mapping.

Key to the development of guidelines will be the input of the LiDAR user community across the country. As part of this project we plan to engage experts, decision makers, data providers and users in a manner that is inclusive and collaborative, in order to gather input for and shape the content of the guidelines. This collaboration will be achieved through several means, including: engaging the provincial and territorial governments on their current specifications, best practices and requirements; conducting a National Meeting in Ottawa in January of 2017 with the LiDAR user community to present findings and propose direction for the new guidelines; and soliciting user comments on the draft guidelines.