New Furrow Flume for High Sediment Loads

Measurement of water flow in furrows from either irrigation or rainfall is difficult when significant soil erosionoccurs. It can be accomplished with flumes that back up flow in the furrow, which for moderate to steeply sloping fields causesonly small changes in furrow water depth and thus has little influence on the water flow measurement. However, the pondingof water upstream from a flume can have a significant impact on the movement of sediment down the furrow. In one researchstudy, measured sediment transport through the flume was reduced 40% over that measured in a furrow with only anon-constricting metal form that matched the furrow shape. A new furrow flume has been designed that overcomes thelimitations of current v-shaped flumes or trapezoidal RBC flumes that cause significant backwater during furrow irrigation.This new flume has a trapezoidal shape with only a side contraction. It was designed to keep flow velocities high over thefull range of flow conditions. This new flume is commercially available and has been working successfully in the field for threeseasons.