Application Of Mathematical For Designing Canal Cross Section

Abstract

Irrigation water conveyance canals are crucial for irrigation, domestic water supply and sewage. As such, they may require substantial amount of investment depending on its length and cross section. Any effort to save the cost of construction or maximize the conveyance also serves to improve agricultural production. Good asset design algorithms can significantly increase the life of an irrigation canal and reduce its life cycle costs. The need to reduce the life-cycle costs of earthen canal banks has been identified as one of the Sudan irrigation highest strategic priorities. Procedures are not presently available for selecting optimum canal parameters directly. Typically, the design of a canal is done by trial and error. Canal design need to consider, whether the canal boundary is erodible or non-erodible. In this study, different algorithms including Manning equation using Newton- Raphson solution method, Regime methods (Kennedy and Lacy methods), Tractive Force Approach, Optimization Area Approach, Velocity constraint method (Minimum permissible velocity as a limit for sedimentation and maximum permissible velocity as a limit for erosion) and Morphological method) are applied to triangular, rectangular, parabolic and trapezoidal crosssections for case of canal running on sedimentary alluvial soils liable to scouring and sedimentation and to stable hard soils. The data from Gezira and Managil canals is utilized as input for various design algorithms and corresponding canal dimensions as output for comparing these algorithms. The Data of Gezira and Managil canals is taken as a design example to demonstrate the applicability and practicability of each one of the proposed methods. The results obtained by applying all algorithms for trapezoidal cross-sections are compared with the Morphological method which adopted as official method of Ministry of Water Resources of Sudan and reported in the literature and used for building the public domain Profile Program xi The result obtained indicate that: Manning equation using Newton-Raphson solution method, Regime methods (Kennedy and Lacy methods), Tractive Force Approach, Optimization Area Approach, Velocity constraint method (Minimum permissible velocity as a limit for sedimentation and maximum permissible velocity as a limit for erosion) and Morphological method in different values of water depths are recommend not to use the Velocity constraint approach for it is not in line with tractive force. Likewise it is not recommended to use Regime methods for Gezira Scheme due to silt build up with time. The design guidelines in this study have been prepared using the accumulated knowledge and practical experience and the study analysis. The research