山区、丘陵中小型灌区,大部分座落于山谷间冲积平原,灌区规模小、引渠长,而且多为环山渠道,坡集水大。如遇集中降雨或暴雨,坡集水流量大于渠道正常流量几倍乃至十几倍,往往使渠堤决口、冲毁渠道、冲毁农田。有些渠道上设有排洪闸,由于无专人管理,不能及时启闭,渠道仍不能保证安全。为此黑龙江省海林市水利技术人员试验研制成功一种轨道式自控闸门。这种轨道式自控闸门是靠闸前水压力克服闸门自重和各部摩阻力沿轨道自动启闭的。它的工作原理是:当闸前水位达到设计水位时,闸门处于临界状态是关闭的。这时由 Most small and medium-sized Irrigation areas in mountains and hills are located in alluvial plain between valleys. The irrigated area is small in size and long in lead channel, and most of them are circular mountain channels with large catchment. In case of concentrated rainfall or torrential rain, slope catchment flow is greater than the normal flow of channels several times or even ten times, often make the dyke break, destroy channels, red farmland. Some channels have flood gates, because no one management, can not open and close in time, the channel still can not guarantee safety. To this end, Hailin, Heilongjiang Province, water conservancy technicians successfully developed a test track-controlled gate. This rail-based self-control gate is by the gate before the water pressure to overcome the self-weight of the gate and the Ministry of friction along the track automatically open and close. Its working principle is: when the water level before the gate reaches the design level, the gate is in a critical state is closed. At this time