Modifying Design Criteria of Side Channels Based On Comprehensive Experimental Observations

This paper presents the impact of different geometric and hydraulic factors on the water surface profile condition in a side channel carrying spatially varied flow with increasing discharge. Comparison between experimental observations and the results of the one dimensional spatially varied flow governing equation, which is the key tool for side channel design, indicated that relaying on such results could lead to insecure design. In this research, based on comprehensive experimental data, that reflect the influence of relevant factors and with the aid of suitable non-dimensional parameters such as a relative water surface irregularity, it is indicated that more than 97% of the mentioned parameter data fall within a arrange equal to the downstream critical depth and one-third of the mentioned depth. Accordingly, the proposed non-dimensional parameters provided a suitable collapse in the data based on which a design criterion was obtained that led to a systematic modification to the numerical results of the governing equation. The proposed modifications were based on an equation obtained for the envelope to the data, therefore, the results inherent a safety factor. The application of the proposed design criteria was presented and the generality of the drawn conclusion was supported by a relatively wide data range of the influencing factors.