In this study, seepage losses have been determined by the direct inflow–outflow method at four selected reaches of the unlined Arrah Main Canal. Grain size analyses of bed materials of all reaches have been carried out, and in situ hydraulic conductivities have been computed using the Guelph permeameter method in all the reaches. The inflow and outflow discharges of all the reaches have been measured using the area–velocity method. The cross-section and velocity profiles at the corresponding canal sections have been measured using an echo sounder and a digital current meter, respectively, upstream and downstream of all the selected reaches. Seepage loss in each reach has been computed using the continuity equation assuming the evaporation losses are negligible. Also, the empirical equations (Molesworth, Offengenden, and Moritz) have been used to calculate the seepage losses in these reaches and compared with the seepage losses determined by the experimental observations. The measured seepage losses in the unlined Arrah Main Canal varied from 3.66 to 13.4 m³/s/10⁶ m². The percentage of seepage losses varied from 2.2% to 8.35%, and seepage losses measured and estimated using empirical equations were comparable.

中文翻译：

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确定 Arrah 主运河中的运河渗漏损失：案例研究*

在这项研究中，渗漏损失已通过直接流入 - 流出方法在无衬里的 Arrah 主运河的四个选定河段确定。对所有河段的床层材料进行粒度分析，并使用圭尔夫渗透法计算所有河段的原位导水率。所有河段的流入和流出流量均采用面积-流速法进行测量。在所有选定河段的上游和下游，分别使用回声测深仪和数字电流计测量了相应运河段的横截面和速度剖面。假设蒸发损失可以忽略不计，则使用连续性方程计算了每个河段的渗漏损失。此外，经验方程（Molesworth，Offengenden，和 Moritz) 已被用于计算这些河段的渗流损失，并与实验观察确定的渗流损失进行比较。在无衬砌的 Arrah 主运河中测得的渗漏量从 3.66 到 13.4 m 不等³ /s/10 ⁶ 米²。渗漏损失的百分比从 2.2% 到 8.35% 不等，使用经验方程测量和估计的渗漏损失具有可比性。