Measuring snow through four Edmonton winters

The challenge

Snow storage sites are managed on figures that are usually estimated. Piles change constantly through hauling, melt and compaction, so a volume taken once means very little. What the operator needs is the volume now and the change since last time, which only works if the capture method is identical every visit.

The sites

Four snow storage sites across north and south Edmonton, captured for the company that manages them. The client is a numbered company and is not named here.

Equipment and method

Mapped capture of each pile to a fixed specification, four to eight times across the season depending on how hauling and melt are running. Snow is genuinely difficult ground for photogrammetry: the surface is bright and low in texture, which gives an image little to match on, and Edmonton's winter light is short and flat. The answer is not a different sensor, it is the same flight plan every time, planned around the forecast rather than postponed by it, so the figures compare to each other rather than to conditions.

Airspace and safety

Municipal sites with heavy truck movement throughout. Capture is coordinated with site operations and launch positions are kept clear of haul routes.

Deliverables

A report per visit covering the volume of each pile and the accumulation or reduction since the previous capture.

Result

Four seasons of consistent figures across four sites, delivered through the part of the year when nobody wants to be outside. The value is in the series rather than any single number: because the method has not changed in four years, the difference between two visits means something.

Read more about volumetric measurement