A Method for Determining Water Flow in Small Rivers Based on Processing Water Surface Video Images

An express method for evaluating water discharge based on calculating surface water flow velocity with the use of PIV-method is considered. A procedure of measurements and an algorithm of software for processing video images of water flow are demonstrated. The results of field studies with the use of the proposed method are presented and compared with those obtained by standard procedures. The proposed method gives real-time data on water discharge in a river or canal without the need to use expensive measurement instruments and trained personnel. The method gives flow velocity field all over the cross section of the studied water body, thus providing more accurate data on water discharge than standard measurement instruments (hydrometers, float method) used in individual points at certain stations. The obtained data on water discharge can be used for scientific substantiation of works for designing bank-protection, channel-regulating marine and river structures, as well as for environmental assessment of the state of a water object at studying water pollution problems. The use of the proposed method at hydrological gages in operation will enable promptly determining water discharge in rivers in a remote regime with the use of appropriate equipment, which is of particular importance for Crimea for assessing peak flow in periods of high freshets and spring floods.