A significant amount of water is lost in canals due to seepage. This could be saved to irrigate barren land. This article presents the measured seepage data by the inflow‐outflow method on seven so‐called concrete‐lined distributary canals in Punjab, Pakistan. A special feature of the inflow‐outflow method is the relatively long lengths of the canal reaches (9 to 5 km), which is the longest one could find in the literature so far. The seepage in canals is also calculated using five empirical formulae. The results show that the Swamee and the Punmia formulae performed admirably with mean percent errors of −20% and + 19% respectively. Moritz formula stood at +53% while Kostiakov scored +158%. The research also proposed a slight modification in the Swamee formula whereby, instead of the canal width, the surface water width was used in the calculation of the dimensionless variable F. This led to a beneficial effect of bringing down the percent mean error from −42% to −20%. © 2020 John Wiley & Sons, Ltd.

中文翻译：

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巴基斯坦旁遮普邦衬混凝土灌溉渠渗流损失分析

由于渗漏，大量的水流失在运河中。可以节省下来灌溉贫瘠的土地。本文介绍了通过流入-流出方法在巴基斯坦旁遮普邦的七个所谓的混凝土衬砌分水渠上测得的渗流数据。流入-流出方法的一个特点是运河段的长度相对较长（9至5 km），这是迄今为止文献中最长的一段。渠道中的渗流也使用五个经验公式来计算。结果表明，Swamee和Punmia公式的表现令人钦佩，平均误差百分比分别为-20％和+ 19％。莫里兹公式为+ 53％，而科斯蒂亚科夫得分为+ 158％。研究还建议对Swamee公式进行一些修改，从而代替运河宽度，F.这带来了有益的效果，将平均误差百分比从-42％降低到了-20％。分级为4 +©2020 John Wiley＆Sons，Ltd.