4　开沟 (渠 )机与防渗渠道成型、施工机要提高地面灌溉水的有效利用率 ,输水渠道是关键。据统计 ,土渠输配水的损失占用水总损失的 60 %～ 80 % ,也就是说 ,我国灌溉水的有效利用率低 (只有 0 4左右 )的原因 ,主要是从水源到田间的输水损失。因此 ,要节水就要把握住输水损失 4 ditching (canal) machine and anti-seepage channel molding, construction machine to improve the effective utilization of surface irrigation water, water distribution channel is the key. According to statistics, the loss of transmission and distribution of waterways accounts for 60% ~ 80% of the total loss of water. That is to say, the reason for the low utilization rate of irrigation water in our country (only around 0 4) is mainly the loss from water sources to the fields Water loss. Therefore, we must grasp the water loss to save water