It was the winter of 2023, and Abiola was a first-year PhD student at Oregon State University who had just arrived in the United States from Nigeria the previous fall. He was completing his final project for CE 513: GIS and Water Resources. The assignment was open-ended: design and carry out a complete GIS analysis that applies course concepts to a real-world problem. Abiola chose the Willamette Watershed, a sprawling 29,000-square-kilometer basin in the Pacific Northwest that stretches from snowy, forested headwaters in the Oregon Cascades down to a broad valley floor. It is water-rich but warming; its land covers a patchwork of forest, agriculture, urban and suburban development, and wetlands. For anyone interested in water resources, habitat conservation, and land use planning, it was a natural laboratory.
Abiola approached the project with a level of care that went well beyond what a typical final assignment required. He assembled nine DEMs from the USGS National Map at one arc-second resolution, merged them, and projected the data to NAD83 UTM Zone 10 to minimize distortion across the basin’s north-to-south elongation. Using ArcGIS Pro, he delineated the watershed and its outlets, generated slope, aspect, and hillshade products, and then ran a full hydrological analysis: filling sinks, computing flow direction and flow accumulation, and defining streams and catchments using an accumulation threshold of greater than 40,000 cells. The result was a drainage network and 447 sub-watersheds, which he characterized using Strahler stream order, drainage density, stream frequency, bifurcation ratio, elongation ratio, form factor, basin relief, and ruggedness number.
The numbers were striking. The Willamette, Abiola’s analysis showed, was an 11th-order basin with more than 1,048,000 streams and over 83,000 kilometers of total stream length. He interpreted the morphometric metrics in terms of erosion susceptibility, drainage efficiency, and watershed behavior, and concluded with a frank discussion of data and scale limitations, uncertainties in DEM-based analysis, and recommendations for validating and extending the approach. Then he turned it in, earned his grade, and moved on.
An Unexpected Email
In July 2026, Abiola received a message he never anticipated. Dr. Joe Torgerson, a supervisory research landscape ecologist at the USGS with more than 24 years of experience, had come across the project while researching the Willamette River basin. Torgerson had been working on Strahler stream order analysis and found Abiola’s DEM-derived estimate of 11th order more current and credible than older pre-DEM studies that had reported a lower, 9th-order classification. He had used the estimate in his own work and wanted Abiola to know.
“My first reaction was pure joy,” Abiola smiled. “I just approached it as a careful, do-it-properly class project. I put a lot of effort into documenting the methods and making the analysis clear. But I didn’t necessarily expect that three-plus years later, a senior USGS scientist would find it, use it, and take the time to email me about how valuable it is.”
What made the project useful wasn’t just the number; it was the documentation. The report walked through the full workflow with maps of the stream network, tables of morphometric parameters, and clear definitions of how stream order was computed and interpreted. It also placed the stream order within a broader morphometric context, embedding it alongside drainage density, bifurcation ratios, basin relief, ruggedness number, and the structure of 447 sub-watersheds. Torgerson’s question about stream order was answered not as an isolated figure but within a fully quantified drainage network.
“It wasn’t just that he used my estimate of Strahler stream order,” Abiola said. “It was the way he described the report—very carefully executed and documented—and then encouraged me to publish it so that others could benefit from it.”
Lessons in Documentation
For geospatial professionals working with elevation data, the case study carries a straightforward but often overlooked lesson: rigor and transparency in documentation can extend the life and reach of technical work far beyond its original purpose.
Abiola’s use of current USGS DEM data at 30-meter resolution, combined with a clearly traceable processing pipeline, gave a federal researcher the confidence to reference the results. His decision to contextualize a single metric within a full morphometric analysis made the work more useful than a standalone number ever could have been. His willingness to discuss limitations and uncertainties openly rather than glossing over them made the report more credible, not less.
“Showing the limitations and uncertainties doesn’t weaken the work,” Abiola said. “It makes it more usable.”
Torgerson suggested that Abiola consider archiving or publishing the project. Now that Abiola has successfully defended his PhD dissertation—he completed his defense just two days before this interview—he plans to submit the report as a citable open document, with the possibility of eventually developing it into a journal article.
What’s Next
Abiola’s geospatial work extends beyond the Willamette project. His PhD research focused on advancing 3D change analysis for reality capture, and he presented on the topic at Geo Week 2025, where he also won the event’s app challenge. He recently interned with AKS Engineering and Forestry and is now looking to return to industry, where he hopes to work with lidar, point cloud data, and other geospatial products to solve real-world problems.
His parting advice to anyone producing geospatial analysis is simple:
“Treat your coursework like real work that someone outside the course might one day rely on. You never can tell who will gain value from what you’ve done and how far that value might reach.”
