Comparing Accuracy Of The Onset And Texas Electronic Tipping Bucket Rain Gauges
Presenter: Dallin Cook1
Co-Author(s): -
Advisor(s): Dr. Martha P.L Whitaker
1Department of Hydrology and Atmospheric Sciences, University of Arizona
The Pima County Regional Flood Control office in Tucson, Arizona relies on field instrumentation to accurately measure precipitation, understand flood risks, broadcast flood warnings, and determine infrastructure needs. It is particularly challenging to accurately model rainfall-runoff patterns in urban watersheds. Tucson receives an annual average of ~12 inches of precipitation, about half of which falls during the monsoon season, (mid-June to late September). We tested the commonly-used ONSET tipping bucket rain gauge in comparison with a new Texas Electronic (TE) tipping bucket gauge that was modified to record more accurately during high-intensity events. The goal was to assess whether the new, more expensive TE gauge measures more accurately than the ONSET gauge. Precipitation data were collected during the 2022 monsoon season at a site on Mt. Lemmon (in the Santa Catalina mountains north of Tucson, Arizona), along with lab tests using a United States Department of Agriculture rainfall simulator. Results indicate that the TE gauge under-recorded at both low-intensity and high-intensity events. We recommend the gauges be further analyzed with the accuracy of a rainfall simulator and during lower-intensity and winter precipitation events.