How to prioritize geotech crew dispatch along a pipeline right-of-way

A corridor doesn't fail everywhere at once. Most integrity teams know roughly which ten or fifteen miles of their right-of-way sit on unstable ground, but "roughly" doesn't tell you which three segments get a crew this quarter. The budget covers a handful of geotech site visits a year. The corridor runs for hundreds of miles. Something has to narrow the list before the trucks roll.

Start with what you already have

Before dispatching anyone, pull together the pieces already sitting in a file somewhere: known landslide-prone soils from state or USGS geologic mapping, steep-slope crossings flagged back in the original route engineering, any segment with a history of slope repair or slip reports, water crossings or drainage changes that have shown up in old aerial photos. This gets you a candidate list, and it's usually longer than a season of field crews can cover.

That's the gap a corridor-wide elevation comparison fills. Stereo-derived elevation models built from VHR satellite or aerial imagery, compared year over year, show where ground has moved: slope creep, toe bulging, a washout scar that wasn't there last season. Run that differencing along the whole right-of-way and the candidate list turns into a ranked one, ordered by how much the surface shifted, not just by which segments look geologically suspicious on a map.

Ranking segments instead of walking the whole line

The traditional way to find movement is walking or flying the right-of-way and eyeballing it segment by segment. It works, but it's slow, it depends on who's looking and how sharp they still are by mile 40, and it happens once a year at best if the budget holds. A corridor-wide elevation comparison does the same screening pass without the boots on the ground, and it holds a consistent standard across every mile, including the stretches nobody got around to walking carefully last fall.

What comes out the other end is a shortlist: these five miles showed measurable surface change since the last pass, these three didn't. That's the input a geotech crew needs before loading the truck. It tells you where to look first. What the crew finds once they're there, a test pit, a slope that's clearly moving, ground that checks out fine, is still their call to make on site.

What a ranked list doesn't replace

Elevation differencing has blind spots worth naming before you build crew assignments around it. It catches surface change: creep, settling, a scarp forming at the toe of a slope. It won't catch subsurface movement that hasn't broken the surface yet, and an annual cadence can miss something that shifts and partly recovers between captures. Depth of cover, pipe wall condition, cathodic protection readings, none of that comes from imagery. It still comes from the integrity data your team already keeps. Treat the ranked segment list as the first filter, not the whole process.

It's worth being plain about where this fits in a program's workflow, too. A ranked list of corridor segments by surface movement is a useful input for planning next season's field work. It isn't a substitute for an ILI run, a geotechnical hazard assessment, or the judgment of an engineer who's walked that stretch of ROW for fifteen years. Its job is cutting fifty candidate miles down to the five worth a site visit first, so the crew spends its time on ground, not on the drive to places that turned out fine.

For a corridor with hundreds of candidate miles and a budget for a handful of site visits a year, the question isn't whether more data would help. It's whether the data in front of you points at the right five miles. Geohazard Screening turns an annual, corridor-wide elevation comparison into that ranked list, built around the one question an integrity engineer needs answered: where to send the crew first.

If your next field season is still an open question, it's worth seeing how that ranking gets built.