Spatial Variability of Sediment Yield in Turkish Basins

It is of great importance to know the amount of sediment transported to water structures and/or irrigation facilities during their planned lifetime. The amount of sediment transported is used in the design of such facilities, thus minimizing sedimentation losses. Determining sediment amount is generally based on empirical and physical modeling and on the relationship between sediment load and stream flow, where the sediment concentration measurements are correlated with flow characteristics. Each of these methods has some weaknesses. This study aimed to prepare a sediment yield map using suspended sediment measurements obtained from the State Hydraulic Works in 114 observation stations with a recording length of 15 years or more. Since the relationship between the amount of sediment and flow rate is known, the flow rate is considered as secondary data and sediment yield is mapped by the co-kriging method. The map showing spatial variation of the sediment yield was evaluated with the calibration and validation stages, and satisfactory results were obtained. Thus, sediment yield can be estimated at a project site where there is no suspended sediment measurement.