Study on the spatial distribution of the contaminants in a eutrophicated lake drainage system

Eutrophication and algae bloom, which are caused by the sharply increasing point and non-point sources contaminants, have been major water quality problems in the Tai Lake drainage system in recent two decades. To find out the spatial distribution attributes of the contaminants (e.g., nitrogen and phosphor), two field trips around and in the Tai Lake system were conducted. 38 sampling points in the river network and 21 points in the lake were selected for sampling and measuring. Stage, discharge, water depth, channel cross sections, PH, conductivity, turbidity, DO, temperature, TDS (Total Dissolved Solids), ORP(Oxidation Reduction Potential) were measured and analysis of NH₄⁺, NO₃^-, PO₄^3-, and TP was conducted. The statistical method was used to evaluate the spatial distribution of contaminants. The results show that in general the north part of the area is more contaminated than the south part, and the lake near Wuxi city in the northwest suffered the pollution and algae bloom most. The detail spatial distribution of the contaminants´ types and the sources were discussed on the whole area. And the result provides the information on the spatial distribution of the contaminants in the eutrophicated Tai Lake drainage system which can help indentify major pollution sources and a good base for further research.