Supplement 1. Interpolated data used to model current velocity and river temperature.

File List Flow_data.csv Temperature_data.csv Description Flow_data.csv contains the comma-separated data used to model current velocity. It contains velocity (km/d) for each River Mile (rm, Column 1) and the corresponding River Kilometer (rk, Column 2), for each day April 1–June 30 (day 1–91, Column 3), for each of 10 years, 1993–2002 (Columns 4–13), and the mean velocity at that river mile and day over ten years (avg, Column 14). Checksum values are: Row 2, no missing values, checksum = 728.68 Row 25390, no missing values, checksum = 1041.92 Temperature_data.csv contains the comma-separated data used to model river temperature. It contains temperature (°C) at each River Mile (RM, Column 1) and the corresponding River Kilometer (RK. Column 2), for each day April 1–June 30 (day 1–91, Column 3), for each of 10 years, 1993–2002 (Columns 4–13). Checksum values are: Row 2, no missing values, checksum = 56.14 Row 25390, no missing values, checksum = 1011.41