An Evaluation of the Causes and Consequences of the Flash Floods (5.9.2023) in the Degirmen River Basin in Igneada (Demirkoy/Kırklareli)

On 5.9.2023, flash floods occurred in Igneada town of Demirkoy district of Kırklareli province, which caused serious loss of life and property. Since this unfortunate event was a natural hazard with a hydro-meteorological characteristic, it occurred at the river basin scale. Therefore, the present study aims to systematically reveal the chain of events leading to the flash floods in the Degirmen River basin, where the natural hazard occurred. The study data were processed and interpreted in the light of the relevant literature within the framework of the findings obtained from office and field studies. At this stage, the Root Cause Analysis (RCA) method was used to determine how and why the event occurred and how to prevent similar problems from occurring again. As a result of the study, it was determined that flash floods caused by sudden torrential rains led to high-energy water flows on the slope lands depending on topographic features. Consequently, they forced the transportation of materials of various sizes. The materials coming from the river's upper basin with strong flash floods with irregularly changing flow rates triggered flooding in places where the slope of the river bed decreased. However, this natural event has become a natural hazard in the lower basin due to the wrong land use caused by the negative anthropogenic effects of human beings on the natural environment.