Calculation of effective hydraulic parameters of concrete irrigation canals

Abstract

When taking water from pre-mountain rivers, for transferring of large amounts of river sediments, rich in mineral fertilizers, along with water to crop fields through irrigation networks requires high sediment transport capacity and deformation resistance from irrigation networks. The projecting and construction of irrigation canals with these features in the foothills requires concreting the canal. The high content of river sediments in the Sokh River (5 kg∙m –3) and the low efficiency of the Right Bank Irrigation Reservoir (10–15%) require high hydraulic efficiency of water intake canals from this system. The main challenge is to reduce costs in concreted canals and ultimately ensure technical superiority. In the research were used generally accepted research methods in hydraulics, in particular field research and consequently, mathematical analysis. Kokandsay, Kartan and Bachkir irrigation canals were accepted as the object of research, the canals were designed on the basis of the best hydraulic section, the canal side slope was taken as a variable parameter and the technical and economic efficiency was checked using computer software. As a result, it was found that the consumption of concrete raw material for 1 running meter can save 0.2–0.3 m 3, depending on the adoption of the canal side slope, the acceptance of the slope of the canal wall at values 1–1.5 will increase up to sedimentation 10%.

Keywords

• canal bottom relative width
• concrete canal
• irrigation canal
• sediment transport capacity
• sedimentation tank
• the best hydraulic section
• trapezoidal shape