Pollution Characteristics and Risk Assessment of Heavy Metal Elements in Sediment in the West Lake of Hengshui Lake

Table 1

I_geo and classification of sediment pollution degree.

Igeo	≦0	0∼1	1∼2	2∼3	3∼4	4∼5	>5
Class	0	1	2	3	4	5	6
Pollution degree	Uncontaminated	Uncontaminated to moderately contaminated	Moderately contaminated	Moderately to heavily contaminated	Heavily contaminated	Heavily to extremely contaminated	Extremely contaminated