Table 1 The generalized linear model and generalized additive model constructed by training data

Estimates for parametric functions

 Intercept

1466* (573)

47.35*** (0.22)

 T

2.64*** (0.19)

–

 DO

0.02 (0.08)

–

 OUR

−0.01 (0.07)

–

 CER

−0.06* (0.09)

–

 SS

0.01 (0.02)

 pH

−3.01 (23.69)

–

 Temp

−45.16* (17.70)

Degrees of freedom for smooth terms

 s(T)

–

7.96***

 s(DO)

–

2.34**

 s(OUR)

–

3.00**

 s(CER)

–

3.71***

 Adjusted R ²

0.940

0.996

 GCV score

44

4