Evaluation of low-cost methods for the measurement of discharge into rivers

Increasing rates of pollution and over-exploitation have reduced the availability of water in many regions of the world. In this context, the qualitative and quantitative management of available water resources becomes paramount. Thus, this study evaluated the applicability of two low-cost discharge measurement methods that are adequately precise: the electromagnetic method and the culvert method. The methods were applied in the field (Ribeirão da Onça Basin) in order to assess their advantages and disadvantages with reference to the conventional method of discharge measurement. Compared with the traditional method, the electromagnetic method resulted in a deviation of -5%, but allowed velocity measurements in the turbulent conditions caused by the channel's side walls. The culvert method resulted in discharge deviations of 2.1%; however, it had limitations in high water situations. The two low-cost methods showed good results in determining the rate of discharge, but it is crucial to understand their operational limitations.