The topography of downstream areas is a critical input to dam breach inundation modelling. Previous PhotoSat work showed that the resolution and accuracy of the input topography significantly affected the simulation results. These findings align with the 2021 CDA Technical Bulletin on Tailings Dam Breach Analysis, which recommends using the highest quality topographic data available.

However, earlier analyses focused on the extremes of data quality, whereas, in practice, datasets span a continuum of resolution, precision, and accuracy. The implications of intermediate data quality on breach modelling outcomes remain insufficiently understood.
This study evaluates two tiers of satellite-derived topographic data: medium-resolution/medium-accuracy DEMs and high-resolution/high-accuracy DEMs. These datasets are applied within breach modelling frameworks across downstream environments with varying terrain morphology and vegetation cover.

The objective is to assess how differences in topographic resolution, precision, and accuracy influence key modeling outputs, including inundation extent, flow routing, and timing metrics such as wave arrival and peak flow. By comparing results across data tiers and terrain types, this work aims to identify where topographic quality materially affects model behaviour and where higher fidelity data may be warranted.