Water Resources Research Act Program

Details for Project ID 2020AZ103B

Flow Discharge Measurements Using Small Unmanned Aerial Systems

Institute: Arizona
Year Established: 2020 Start Date: 2020-03-01 End Date: 2021-02-28
Total Federal Funds: $10,000 Total Non-Federal Funds: $20,000

Principal Investigators: Dr. Jennifer Duan

Project Summary: Obtaining accurate measurements of river discharge at or above flood stage has long been a challenging and dangerous task in the southwestern United States (U.S.) where flows are flashy and sediment concentrations are high. To obtain accurate measurements of flow withoutcompromising the safety of field technicians, the U.S. Geological Survey Arizona (USGS) WaterScience Center has deployed small Unmanned Aerial Systems (sUASs) to hydrographers acrossthe state. Using the footage collected with the sUASs along with Large Scale Image Velocimetry(LSPIV) techniques, a detailed surface velocity distribution is obtained. This measured velocitydistribution is used to calculate flood discharge when multiplied by the velocity index and thecross-sectional area. Importantly, the quality of the discharge calculation is directly correlated with the accuracy of the velocity index value. To fully utilize the capacities of velocity measurements such as those captured with sUASs, Johnson and Cowen (2017) developed a remote method of estimating the velocity index in a laboratory setting with encouraging results. The goal of this project is to verify if the method Johnson and Cowen (2017) developed in a lab can be applied to the field. To test the veracity of the method, velocity index and discharge measurements will be calculated for lined, earthen, and natural channels in Yuma, Arizona using the procedures outlined by Johnson and Cowen (2017). As discharge in the channels fluctuate daily to meet irrigation and power demands, data will be collected at a variety of depth, discharge, and roughness values. The calculated velocity index and discharge measurements will be compared with known measurements collected with acoustic doppler current profiler (ADCP) sensors to determine the accuracy of the method. The results from this project have the potential to influence the future of techniques and methods used to make flow measurements in the southwestern U.S. as they help unlock the full potential of sUAS measurements. To communicate the findings of this project, video footage will be recorded throughout the process and edited into concise video to be distributed to USGS employees across Arizona and the nation.