No. 4. May

Water is an expensive resource and farmers often do not have enough water to meet their irrigation needs. An adequate water management program, at the regional or farm level, requires the installation of metering structures along distribution networks to regulate water allocations to different fields, as well as recognition of the need for canal lining to prevent seepage losses. Generally, there are structures or mechanisms for measuring surface water at the sites where surface water is collected or at the outlet of deep wells. In most cases, there are few measuring structures built in the distribution network and the irrigation water delivered to the fields is estimated visually, which generates excessive water losses due to percolation and runoff at the end of the furrow. One of the ways to deal with periods of drought is to improve the efficiency of irrigation water use. To achieve this, it is necessary to measure the flow available in the irrigation ditches. There are currently a large number of structures and mechanisms for measuring water in canals, which differ in both accuracy and cost. Among the best known are: the windlass, submerged orifices, trapezoidal, rectangular and triangular weirs and WSC, Parshall and collarless flumes. The RBC flume is also available, which has advantages due to its ease of installation, economical construction and accuracy in gauging. Weirs are structures in which the flow control selection is formed by an elevation built on the bottom of the channel, while in flumes or channels, the flow control is achieved by narrowing the channel walls. In the case of the RBC, it could well be called a weir or a wide-crested flume. |