Analysis of the Influencing Factors of Variation in Sediment Concentration in the Lower Değirmendere Basin, Trabzon, Türkiye

This study aimed to investigate the variation of total suspended sediment concentration (TSS, mg/L) from upstream to downstream as well as its variation during the sunrise and mid-day periods. The Lower Değirmendere Stream Basin was selected as the study area. Sampling and monitoring studies were conducted weekly, four times a month, from December 2021 to May 2022. Samples were taken on four gauging stations upstream to downstream. Sunrise samples were taken between 06.00–07.00 a.m. and mid-day samples were taken between 12:00 a.m.–01:00 p.m. Over the 24-weekly sampling period, the variation TSS were characterized. The samplings and laboratory experiments were used to evaluate TSS. The results have indicated that TSS increases from upstream to downstream and the TSS values at mid-day were 20–75% higher than at sunrise. It has been shown that anthropogenic activities in the Lower Değirmendere Stream Basin cause an increase in TSS concentration. The fact that anthropogenic activities in the Basin is low at night has resulted in low mixing into the stream and therefore low TSS concentrations.