Multidimensional Connection Cloud Model Coupled with Improved CRITIC Method for Evaluation of Eutrophic Water

Table 6

Classification standard of water eutrophication evaluation index [54].

Water quality index	Classification
	I	II	III	IV	V
TP (ug/L)	<1	<4	<23	<110	<660
COD (mg/L)	<0.09	<0.36	<1.80	<7.10	<27.10
SD (m)	>37	>12	>2.4	>0.55	>0.17
TN (mg/L)	<0.02	<0.06	<0.31	<1.20	<4.60