Hydrosocial Principles; WaterHumanNature Nexus

The construction of structures such as gutters, despite erosion control, can be  due to the formation of a localized flow structure such as sudden expansion and contraction at the flow passage, the formation of downstream flow, and its impact on the channel bed upstream of the gutter and The shear layer and the resulting turbulence can cause local erosion and threat to the structure. In this research, using the twodimensional numerical model SRH2D, the flow pattern around the spur dike wall was simulated with angles of 45, 90, and 135 degrees in the channel. The results showed that with an angle of 45 degrees, the length of the return zone of the stream will be about 2 and 8 times shorter than the 90 and 135° angle, respectively. However, in a spur dike with a 90 degree angle, the length of the return zone is about 3.5 times shorter than when the breaker is located at an angle of 135 degrees in the channel. Also, shear stress in the areas close to the floor in the spur dike with an angle of 45 degrees is the lowest value and the breaker with an angle of 135 degrees has the highest value.