Precision and accuracy of streamflow measurements in headwater streams during baseflow

Abstract

The quantification of baseflow is key for water resources management. However, there are few reports on the precision and accuracy in low streamflow measurements. In this paper, we systematically analyze the precision and accuracy of dilution streamflow measurements in headwater channels during baseflow. Precision refers to the variability of the values for repeated measurements and accuracy is how much the measured value approximates the reference one. We measured streamflow in 31 different cross-sections with contributing areas ranging from 0.02 to 5.33 km2. Streamflow measurements with the current meter were adopted as reference for accuracy estimation. A precision error of ±5.0% was found for the measurements. The percent errors compared to reference streamflow ranged from 0.7 to 45.6%, with a median of 6.1%. Precision and accuracy are in the same order of magnitude found in the literature for larger streams. These results can be used for constraining the uncertainty of streamflow measurements and rainfall-runoff modeling of headwater streams.

Natural responses of Neoproterozoic dynamic karst springs to rainfall events, São Miguel Watershed, Minas Gerais, Brazil

“…The measurements were used to develop rating curves and, by using the mathematical relationship between stage and discharge, the 15 min time‐step water‐level height records were converted into continuous discharge records, resulting in karst spring hydrographs (Turnipseed & Sauer, 2010). According to Leonard et al (2000), Herschy (2002), and Santos et al (2021), the median errors in rating curves can be approximately 6%.…”

“…According to Leonard et al (2000), Herschy (2002), andSantos et al (2021), the median errors in rating curves can be approximately 6%.…”

Uncertainties in measuring and estimating water‐budget components: Current state of the science

“…This method is particularly useful for rocky or very shallow headwater streams at low flow and in small streams with turbulent flow where the velocity-area method is not appropriate. Errors on the order of ±5% are reported for this method under favorable conditions (Day, 1976;dos Santos et al, 2021). During short-lived flood peaks in small streams, when manual streamflow measurements are logistically difficult, the continuous slope-area method (Smith et al, 2010) can be applied to constrain the upper range of a stream rating curve.…”

A coupled 2D-3D catchment-lake model with a parallel processing framework

“…The Peri Lake catchment is located in Santa Catarina Island, southern Brazil (Figure 5), with average annual precipitation of 1500 mm (Chaffe et al, 2021;Hennemann & Petrucio, 2011). The lake surface area is 5 2 km with average depth of 7.0 m and maximum depth of 11.0 m. The surrounding hillslopes are covered by remains of Subtropical Atlantic Rain Forest and sandy Restinga (Perez et al, 2020;Santos et al, 2021). It is the largest source of water supply on the Island and an important ecosystem for biodiversity preservation.…”