The Impacts of Precipitation on Fluorescent Dissolved Organic Matter (FDOM) in an Urban River System

Precipitation is considered a key factor influencing the fluorescent dissolved organic matter (FDOM) of urban rivers. However, multiple effects precipitation on FDOM in rivers and long-term impacts spatial patterns are seldom known. Spatiotemporal variations at 36 sites from Jinan City during dry wet seasons were investigated this study. Four components identified using an excitation–emission matrix parallel analysis. Overall, total fluorescence intensities ranged 6.59 to 35.7 quinine sulfate units (QSU) 3.42 69.3 QSU, respectively. Significant found for different that C2 C3 declined but C4 increased season (p < 0.05). The temporal could be explained by combined dilution flushing. Three reference sources, including background water, spring wastewater treatment plant (WWTP) outlets, illustrated principal coordinate analysis (PCoA). places most more closed PCoA location WWTP outlets while central shifted season. changes sources mixed effect precipitation. In conclusion, study provided new insights into river systems, also data support precise pollution discharge water resource management.