LAUSR

Check gates being installed in a main open canal work to maintain water at a constant level in order to ensure water distribution to secondary canals. This type of water distribution is called the constant upstream water level control in Japan, and this type is suitable for supply-oriented water control. Although this type can supply more water compared to the canal structural size, the water supply and distribution schedule must be kept rigidly, and farm turnouts in upstream reaches are apt to withdraw more water than allocated, which leads to unfair water distribution. Recently, tele-meter and tele-control (TM/TC) systems have become more easily applicable to an irrigation system, and in some key points TM/TC devices are actually equipped to check and control water flow. However, their abilities in reality are not fully utilized to respond to the earnest requests of farmers, such as, flexible and labor-saving water use, or fair water distribution between upstream and downstream areas. This study aims to seek useful managing methods to solve the above problems by fully utilizing TM/TC devices to be installed at all check gates. These devices transmit data and commands between a central office and terminals, or they process data independently to control structure at each terminal. Firstly, the A Yousui, the most advanced irrigation system in Japan, is kept in mind, and a new operation system is proposed for demand-oriented water control, which can automatically respond to water demands but also can convey a relatively large flow rate. Secondly, for the T Yousui, a popular irrigation system, another operation system is proposed to solve the unfair distribution problem between upstream and downstream areas. These proposals are led based on numerical experiments using a numerical model, the facilities’ data in place, and water distribution records.