Table 2 Summary of initial and calibrated parameter values used in the extended Streeter-Phelps model for all rivers.

k_d

Deoxygenation rate

0.3

0.25–0.35

day⁻¹

Chapra¹²; adjusted

k_r

Reoxygenation rate

0.5

0.45–0.55

day⁻¹

Cox¹⁶; adjusted

k₃

Organic load decay (BOD)

0.1–0.3

0.15–0.28

dimensionless

Empirical tuning