FIGURE 4 in Fish die-off in river and reservoir: A review on anoxia and gas supersaturation

FIGURE 4 | TDG and DO saturations for periods with intense (red) and sporadic (blue) dam spillway activities. Four models were fitted to these data, all with TDG as a response and DO as a predictor. The models were: i) simple linear regression (Linear); ii) linear regression with quadratic effect of DO (Quadratic); iii) segmented linear regression, with 1 breakpoint and 2 segments (Segmented (1)); iv) segmented linear regression, with 2 breakpoints and 3 segments (Segmented (2)). The most parsimonious model with the lowest AIC was segmented regression (2).