Study on Water Quality Inversion Model of Dianchi Lake Based on Landsat 8 Data

Table 7

Fitting model of DO concentration.

Factor	Model	R ^2	Functional relation
B1/B7	Cubic	0.819	y = 0.0005x3 − 0.0307x2 + 0.2222x + 9.299
B1/(B1 + B7)	Cubic	0.819	y = −13122x3 + 34968x2 − 31065x + 9209.4
(B1 − B7)/(B1 + B7)	Cubic	0.820	y = −1640.2x3 + 3821.3x2 − 2969.2x + 778.67
B1 − B7	Linear logarithm	0.631	y = −0.0139x + 12.958
B1 + B7	Linear logarithm	0.580	y = −0.0143x + 13.99