Experimental Study on Uncertainty Assessment of ADCP Discharge Measurement using GUM Framework

Jongmin Kim, Dongsu Kim, Seojun Kim, Soojeong Kim

Thursday 2 july 2015

9:00 - 9:15h at Africa (level 0)

Themes: (T) Special session, (ST) Acoustic monitoring of flow, turbulence and river discharge

Parallel session: 10F. Special session: Acoustic monitoring of flow, turbulence and river discharge

Acoustic Doppler Current Profilers (ADCPs) have been widely utilized for assessing streamflow discharge, yet few comprehensive studies were conducted to evaluate discharge uncertainty in consideration of individual uncertainty components. It could be mostly because it was not easy to determine which uncertainty framework can be appropriate to rigorously analyze streamflow discharge driven by ADCPs. In this regard, considerable efforts have been made by scientific and engineering societies to develop a standardized theoretical framework for uncertainty analysis in hydrometry. One of the well-established UA methodology based on sound statistical and engineering concepts is Guide to the Expression of Uncertainty Measurement (GUM) adopted widely by various scientific and research communities. This research fundamentally adapted the GUM framework to assess individual uncertainty components of ADCP discharge measurements, and subsequently provided results of a customized experiment in a controllable real-scale artificial river channel. We focused particularly upon sensitivities of uncertainty components in the GUM framework driven by ADCPs direct measurements such as depths, edge distance, submerged depth, velocity gap, sampling time, repeatability, bed roughness and so on. Both stationary and moving boat measurements of ADCPs were considered for uncertainty analysis as well. All of measurements were carefully compared with data using other instrumentations such as ADV to evaluate individual uncertainty components. This research was supported by a grant(11-TI-C06) from Advanced Water Management Research Program funded by Ministry of Construction & Transportation of Korean government.__