风沙区，一般地面起伏不平，常需修高梁以高水位送水，这样不但明显增加了渠系占地面积或能耗，而且水的损失大，斗渠以下架系水的利用率仅为60％。同时加大了输水管理的工作量。由经济评估可知，明渠灌溉改管道灌溉后，在分析期内平均可获得净效益42664元／hm2，内部回收率为2 Wind and sand area, the general uneven ground, often need to repair the beam to high water level, which will not only significantly increase the canal area or energy consumption, and the loss of water, ditches below the utilization of water system is only 60%. At the same time increase the workload of water management. From the economic assessment, we can see that after the open channel irrigation was changed to piped irrigation, the average net benefit obtained during the analysis period was 42,664 yuan / hm2 and the internal recovery rate was 2