由于管道输水灌溉优点突出,近些年来,许多国家,特别是发达国家,出现了由明渠灌溉向管道输水灌溉发展的趋势。据一些国家灌区资料分析,没有衬砌的灌溉渠系输水损失占总引水量的30～40%,有的甚至达60%;利用管道输水灌溉系统,可以减少蒸发损失和渗漏损失,灌溉水利用系数可以提高到90%以 In recent years, many countries, especially the developed countries, have witnessed the trend of developing irrigation from open channels to piped waterways due to the prominent advantages of piped water irrigation. According to the data of some national irrigation districts, the water loss of irrigated canal systems without lining accounts for 30-40% of the total water diversion volume, and some even reaches 60%. By using the pipeline water supply irrigation system, evaporation loss and leakage loss can be reduced, irrigation water Utilization factor can be increased to 90%