InQUIRI

InQUIRI: Inferring Q (discharge) from UHJ’s (undular hydraulic jumps) Identified in River Images

This standalone software application provides an integrated set of tools for inferring river discharge Q from remotely sensed data based on critical flow theory, a method introduced by Legleiter et al. (2025). This approach can yield accurate streamflow estimates in rivers with well-defined standing wave trains, referred to as undular hydraulic jumps (UHJ's). Once an image with clearly expressed UHJ's is identified, simple measurements of the spacing between wave crests and the width of the channel are the only two inputs required to calculate discharge Q under an assumption of critical flow. The program is thus referred to as Inferring Q from UHJ's Identified in River Images, or InQUIRI for short.

Legleiter, C.J. Grant, G.E., Bae, I., Fasth, B., Yager, E.M., White, D.C.,Hempel, L.A., Harlan, M.E., Leonard, C.M., and Dudley, R. (2025) Remote Sensing of River Discharge Based on Critical Flow Theory. Geophysical Research Letters, 52, e2025GL114851. https://doi.org/10.1029/2025GL114851.