Factors affecting behavior and distribution of dissolved organic matter in an artificial coastal reservoir

Abstract

Measurements were conducted in each season (four times) during 2019 at thirteen sites within the Saemangeum Reservoir, which is an artificially constructed reservoir located in a coastal region, to determine factors affecting the behavior and distribution of dissolved organic matter (DOM). The spatial distributions of particulate organic nitrogen, particulate organic phosphorus, and Chlorophyll-a indicate addition reactions in the low salinity region of the reservoir. Results of principal components analysis showed an increase in the amount of allochthonous DOM with a decrease in salinity. The changes in particulates and DOM imply an increase in dissolved organic and inorganic matter, which is attributed to the degradation of particulate organic matter. Therefore, the organic matter distribution is influenced both by dilution from the external upstream origin and the artificial operation of the sluice gate. In addition, the restricted mass transfer relating to salinity stratification from the bottom to the surface causes an increase in inorganic nutrients.