DISCHARGE MEASUREMENTS IN IRRIGATION CANALS USING MULTIFREQUENCYACOUSTICS

摘要

The application of acoustic Doppler technology for water velocity measurements wasinitiated in the late 1970’s as an oceanographic application and has evolved into a reliablestandard for discharge measurements throughout the world. The increased demand andpricing for water resources has also created the demand for increased precision andaccuracy for water users particularly in the irrigation industry. SonTek’s Next GenerationRiverSurveyor products, the S5 and M9, present end users with a new dischargemeasurement instrument that is easy to use yet highly robust in its data collection andprocessing. Typical discharge measurements with the S5 or M9 take only a fraction of theeffort when compared to traditional gauging instruments. Multiple frequencies presentusers a high resolution velocity profile, as well as an extended bottom tracking range.Using the new system, the built-in echo-sounder and multiple frequencies allow thesystem two options to define cross-sectional area that are extremely accurately regardlessof depth. The echo-sounder measures directly below the instrument to measure exacttransect profile; this feature eliminates extrapolation errors of the traditional acousticDoppler profilers by accurately defining discharge cross-sectional area, a key componentwhen calculating discharge. The Next Generation RiverSurveyor has been used inirrigation districts in the Southwestern US, as well as throughout the world. Case studieswill be presented analyzing a wide range of gauging scenarios, while highlighting thebenefits of the technological advancement.