A Proper Way to Install Trapezoidal Flumes for Measurements in Furrow Irrigation Systems
Mohammad Shayannejad1, Saeid Eslamian1, Amir Gandomkar2, Maryam Marani-Barzani3, Mahboubeh Amoushahi-Khouzani4, Zahra Majidifar5,Foroozan Rajaei-Rizi6, Masoud Kazemi7, Vijay P. Singh8, Shahide Dehghan9, Hamid-Reza Shirvani-Dastgerdi2, Hossein Norouzi10, Arsalan Malekian 9,Kaveh Ostad-Ali-Askari9*
Citation :Kaveh Ostad-Ali-Askari,et.al, A Proper Way to Install Trapezoidal Flumes for Measurements in Furrow Irrigation Systems International Journal of Research Studies in Agricultural Sciences 2017,3(7) : 1-5
Accurate measurements of hydraulic characteristics of flow are needed for design and evaluation of irrigation systems. For measuring flow, flumes are commonly used. is in order to obtain accurate readings for flow measurement, flumes should not be submerged and the upstream flow should not be affected by the downstream flow. This study investigates a proper way to install trapezoidal flumes that can be applied in many ways to measure in flow and outflow discharge in furrow irrigation systems. During sixty field operations, it was discovered that the flume has to be installed at least four centimeters above the bottom of furrow, in addition to the alignment on each side. This is essential for proper functioning of the flume under the conditions of free flow., Measurements made showed that if flume was held four centimeters above the bottom, the percentage of submergence in different depths of water, had met the standard rate (lower than 70% submergence), and hence the percentage of the error in flow measurement was reduced. In order to ensure the free flow in the trapezoidal flume, the large number of field operations showed that the entrance of the flume, which is used to analyze the inflow, has to be installed at a height of four centimeters or more above the bottom of furrow, with the condition that its entrance borders are strengthened. The exit of the flume should also be firmly fixed on the bottom of furrow in order not to impede the passage of flow, with the condition that beneath the flume the furrow bottom should be made deeper in order to create free flow. These recommendations are important, especially in furrow irrigation systems.