A Low-Cost Ultrasonic Sensor for Online Monitoring of Water Levels in Rivers and Channels

Abstract

The measurement of flow parameters in rivers and channels is essential for anticipating floods, hydraulic modeling, and conducting water resource management studies. However, the high cost of existing equipment has resulted in a shortage of monitoring stations compared to actual requirements. This research focused on developing and validating a low-cost, highly accurate ultrasonic device that minimizes malfunctions for online monitoring of water levels in channels and streams. Considering the availability of components, cost, and the reported resolution of the product, the GY-Us42 sensor was selected for constructing the level gauge. The sensor operates within a range of 20 cm to 720 cm with a measurement accuracy of approximately 1 mm. The device integrates several error reduction mechanisms to enhance accuracy, including averaging multiple readings and temperature correction techniques. Laboratory data and field data gathered by both staff and shaft encoder were used for device validation. After constructing the main prototype and conducting various tests, multiple devices were installed in different locations within the Tehran rivers, and water depth data were collected over a specific period. Subsequently, data from other field sensors were also collected and used for device validation and accuracy assessment. The results indicate that the device's average error is below 3%, with a Root Mean Squared Error (RMSE) of 5.00 cm during field tests, demonstrates that the constructed device is an efficient tool for measuring water levels in streams, particularly during flood events.