Investigation of the effect of precipitation on the change ofsuspended sediment amount in Kavaklidere basinusing rusle model

Soil formation and soil losses are in an ideal balance under natural conditions. It is known that the rate of soil formation in nature is always higher than the rate of soil losses. However, the natural balance in the soil cycle can be rapidly deteriorated by human action. It also brings serious problems in ecological, psychological, social and economic fields. For this reason, monitoring and prevention of soil losses have become very important today. The Kavaklıdere basin, in which a change was observed in the amount of soil losses according to the DSI (State Hydraulic Works, responsible government body for water related issues in Turkey) suspended sediment observation data of 2012 and 2018, was examined within the scope of this study. The reasons for changes of suspended sediment amount in the Kavaklıdere basin has been studied with RUSLE (Revised Universal Soil Loss Equation), RS (Remote sensing), GIS (Geographic Information Systems) methods and modeling studies using ArcGIS software. As a result of the basin characteristics included in the RUSLE equation were examined, it was determined that all parameters except R (the erosional power factor of precipitation) remained constant throughout period observed. For this reason, the effect of precipitation on the amount of soil loss was determined with the model prepared for two different time intervals. Calculated and measured sediment amounts were compared, and the changes between two sediment yields were examined proportionally. Although there is a significant difference in the amount of sediment obtained from the model and the measurements, the rate of change of the model results and the measurement data were found to be compatible with each other. The fact that the proportional changes of the calculated and observed sediment amounts are close confirms that the change occurred with the effect of precipitation. In addition, it has been determined that the most important factor in the formation of the large difference between calculated and the measured sediment amount in this study is the SDR (Sediment Delivery Ratio).