复式断面渠道渠系水利用系数测算方法研究

Study on Calculation Method of Water Utilization Coefficient of Canal System of Duplex Section

【目的】研究采用复式断面渠道的灌区渠系水利用系数更精确地测算方法。【方法】采用动水测定法测定了渠道各断面水力要素,之后通过修订后的戴维斯-威尔逊公式和考斯加科夫渠道渗漏经验公式求得研究区域复式断面渠道渠系水利用系数,对比分析了各渠道水损失以及渠系水损失量。【结果】动水测定法更适合不断流复式断面渠道水力要素的测算;采用标准梯形断面渠道衬砌的方式渠道损失最小;考斯加科夫渠道渗漏经验公式求得灌区渠系水利用系数为0.75,而戴维斯-威尔逊公式求得灌区渠系水利用系数为0.82,更加接近实际值0.86,精确度提高了9.5%。【结论】由于占地、开挖等影响因素,灌区渠系衬砌后多形成复式断面渠道,灌区渠道衬砌优先采用标准梯形断面衬砌方式。对于这类渠系工程,动水测定方法明显优于典型渠道测量方法,戴维斯-威尔逊公式也更适用于复式断面渠道的渠系水利用系数的测定。

【Objective】We aimed tostudy on a more accurate method for calculating the water use coefficient of canals in a compound section of an agricultural irrigation area 【Method】In this paper, the hydrodynamic factors in each section of the channel were determined by the dynamic water measurement method. Then, the revised Davis-Wilson formula and the Kosgakov channel leakage empirical formula were used to obtain the water utilization coefficient of the multi-section canal system in the study area. Water loss in each channel and canal water loss of the canal system were compared and analyzed. 【Result】The dynamic water measurement method is more suitable for the calculation of the hydraulic elements of the continuous flow section channel system. The standard trapezoidal section channel lining method has the least loss. The Kasgakov channel leakage experience formula is used to obtain the canal water utilization coefficient of the irrigation area being 0.75. The Davis-Wilson formula finds that the canal water utilization coefficient of the irrigation area is 0.82, which is closer to the actual value of 0.86, and the accuracy is improved by 9.5%. 【Conclusion】Due to the influence factors such as land occupation and excavation, the multi-section canal system is formed after the lining of the canal in the irrigation area. The channel lining of the irrigation area is preferably lining by trapezoidal section. For this type of canal system, the dynamic water measurement method is obviously superior to the typical channel measurement method. The Davis-Wilson formula is also more suitable for the determination of the canal water utilization coefficient of the complex section canal system.