2.1 Basin descriptions
We focused on the Willamette river basin (WRB) and the Yakima river
basin (YRB), which are both part of the Columbia River watershed,
located in the Pacific Northwest United States (Figure 1). The WRB in
central Oregon covers an area of 29,636 km2 with 9756
individual stream reaches, while the YRB in southeastern Washington
state is approximately half the size (15,887 km2) and
contains 6538 individual stream reaches (Figure 1). We selected these
two basins because they differ in terms of biophysical characteristics
(Fulton et al. 2024), including precipitation, topography, and land
cover (Figure S1).