Submerged Grain Size Maps in the Santiam River Basin, Oregon

The size and distribution of riverbed grain size plays a foundational role in river morphology and ecology. This study (White and others, 2025) quantifies submerged riverbed grain size at high resolution (1 square meter) across 260 kilometers of geomorphically diverse river corridors in the Santiam River Basin, Oregon, by pairing bathymetric lidar point-clouds collected in 2023 with georeferenced pebble counts. This data release documents the grain size model results of the study, including the median grain size (“D50”) and 84th percentile (“D84”) results for each of the seven study reaches, including the North Santiam River below Big Cliff Dam (“lower North Santiam”), the Little North Santiam River, Breitenbush River, North Santiam River above Detroit Reservoir (“upper North Santiam”), the South Santiam River below Foster Dam (“lower South Santiam”), Quartzville Creek, the Middle Santiam River, and the South Santiam River above Foster Reservoir (“upper South Santiam”). This metadata provides an overview of the data, but users are encouraged to read the associated study for details on model development and limitations (White and others, 2025). Notably, published datasets are limited to areas where bathymetric lidar returns were at least 5 points per square meter, and areas not achieving this point density were removed.

Citation and link for associated journal article: White, J. S., Bartelt, K., Overstreet, B. T., & Kelley, J. R. (2025). High resolution mapping of submerged sediment size and suitable salmon spawning habitat using topo‐bathymetric Lidar in the Santiam River basin, Oregon. Water Resources Research, 61, e2024WR039219. https://doi.org/10.1029/2024WR039219