A Planning-Scale Permafrost Hazard Susceptibility Framework for Municipal Development Review in Iqaluit

Abstract

Permafrost conditions strongly influence ground performance in Arctic communities, yet thaw related land information is not always available in a form City planning and development review staff can readily use. In Iqaluit, development review occurs within a context shaped by housing pressure, servicing constraints, climate change, and spatially variable permafrost. This thesis addresses the need for a planning-scale spatial reference that helps staff consider permafrost thaw related susceptibility as proposals are assessed against planning policies, by-laws, City objectives, and technical and safety requirements.

The thesis develops a planning-oriented framework for producing a Permafrost Hazard Susceptibility Index (PHSI) and displaying the resulting classes through a planner-facing overlay for the populated area of Iqaluit, Nunavut. Using an applied, qualitative, single-case design and document analysis, it brings together literature on permafrost processes, susceptibility mapping, engineering standards and guidance, and Iqaluit's policy and development review context. The review considers subsurface physical, thermal, and mechanical conditions together with snow, vegetation, surficial geology, topography, drainage, and hydrology.

The framework distinguishes thaw potential from thaw impact. The Thermal Response Index (TRI) and Ground Thermal State (GTS) form a Thaw Potential Index (TPI), which is combined with a Thaw Impact Index (TII) to produce the PHSI. It explains how mapped and local technical evidence can be rated, combined, classified, calibrated, and validated. It also distinguishes baseline and future ground conditions, sets minimum evidence requirements, reports confidence separately, and retains Unknown / Insufficient Data where a class cannot be supported.

An illustrative application shows how baseline and future PHSI classes could inform discussions during the City's planning and development review process concerning height and density, servicing, development intensity, further geotechnical investigation, and mitigation. The study does not produce a calibrated operational map or replace site-specific investigation, engineering design, expert judgement, or decisions made through that process. Rather, it provides a transparent planning-scale framework for translating scientific, engineering, and planning knowledge into a practical reference for a thaw-sensitive northern city.