Method for quantitatively analyzing contribution of algae source to CODMn in water body

The invention discloses a method for quantitatively analyzing contribution of an algae source to CODMn (Chemical Oxygen Demand) in a water body. The method comprises the following steps: selecting a typical section for continuously monitoring and collecting a water sample and enriching an algae sample; measuring related water quality parameters and algae indexes; calculating a theoretical algae source COD (Chemical Oxygen Demand) through a conversion model of the algae biomass (BioM) and COD; establishing a fitting relationship between the chlorophyll a content and theoretical COD; and constructing a model for predicting the contribution rate of the algae source CODMn to the water body CODMn by the chlorophyll a. The method for rapidly and quantitatively analyzing the contribution of the algae source to the CODMn of the water body through chlorophyll is established, so that a basis is provided for tracing analysis of river pollution with the CODMn abnormally increased and algae control intensity, precise trea