Calculation of flow deviation rate of drip irrigation system taking three deviation rates into account on uniform slopes

Based on the method for calculating flow deviation of drip irrigation system taking hydraulic deviation and terrain slope into account, according to the disadvantage combination principle and the probability theory, the effect of manufacturing deviation on flow deviation rate was analyzed to imitate flow deviation of drip irrigation system accurately for designing drip irrigation system economically and credibly. The relationships between flow deviation rate and manufacturing deviation rate, hydraulic deviation rate and terrain deviation rate in drip irrigation system were established on uniform slopes by hydraulic calculation and mathematic consequence. Taking the three deviation rates into account, a formula for computing the flow deviation rate was deduced. The formula can simulate flow deviation rate at different guarantee rates for a drip irrigation system, which is simple and practical. It can be used in the design of drip irrigation project.