Distribution and Ecologica Risk of Sediment Heavy Metals in the Water-Level-Fluctuation Zone of the Shawan River Section of Yelang Lake

Table 1

The classification of multiple heavy metal comprehensive potential ecological risk index (RI) and single heavy metal potential ecological risk index ().

Degree of pollution	Mild	Moderate	Strong	Very strong	Extremely strong
Potential ecological risk index of single heavy metals ()	<40	40–80	80–160	160–320	≥320
Integrated potential ecological risk index of multiple heavy metals (RI)	<150	150–300	300–600	≥600	—