Mapping blue spots

, , ,

Partager cet article

Client

Communauté métropolitaine de Québec (CMQuébec)

Funding

OASIS program of ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (MELCCFP).

Objective

The CGQ team aims to provide CMQuébec, as well as its regional and local partners, with detailed mapping based on the Balstrøm and Crawford (2018) method and precipitation scenarios. Ultimately, this mapping, combined with other geomatics data, will enable various stakeholders to guide greening efforts and the implementation of green infrastructure to help adapt to heat waves and heavy precipitation.

Methodology

  1. Preparation and hydro-consistency of the DTM:
  • “Burning” of watercourses, bridges, viaducts and culverts.
  • Integration of buildings into the DTM using fictitious elevation values.

2.    Detection of blue spots (Balstrøm method):

  • “Identify Bluespot Features” tool.
  • Creation of topology (nodes/edges) and simulation using “Assembled Bluespot Workflow.”

3.    Characterization and scenarios:

  • Calculation of characteristics per basin (area, potential volume, maximum depth, connectivity).
  • Water height classes (0–50 mm; 50–100 mm; 100–300 mm; > 300 mm).

4.    Validation and cleaning:

  • Automated checks and expert review.
  • Consideration of past events.
  • Elimination of false positives.
  • Production of final data, an ArcGIS Pro tool, a guide, and a technical report.

Equipments

Software/environments:

  • ESRI ArcGIS Pro (ModelBuilder, geoprocessing),
  • Python scripts,
  • ETL processes (topological validation, harmonization, traceability).

Key data (provided by the CMQuébec):

  • 1 m DTM (LiDAR fusion),
  • building and pool footprints (AI),
  • roads and bike paths (lanes/widths),
  • culverts,
  • retention basins,
  • very high-resolution imagery.

Fields

Municipal geomatics

Environmental monitoring

 

Similar projects