Spatial Distributions of Humic Substances and Evaluation of Sediment Organic Index on Lake Dalinouer, China

Table 5

Classification of sediments based in standard organic indexes.

Organic index	Grade	Type
<0.05	I	Clean
≥0.05–<0.20	II	Relative clean
≥0.20–<0.50	III	Slight pollution
≥0.50	IV	Pollution