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In practice, there are several techniques used to estimate the rates of runoff in urban and rural areas, each technique having its advantages and limitations. It is up to the administrators of water resources to assess the advisability of applying these technologies, according to their accuracy in various contexts relating to their costs of acquisition and maintenance. The purpose of this article is to analyze the deviation between the flows estimated by means of traditional rating curve and those measured directly by the Argonaut SW (shallow water) type Doppler. The proposed methodology consists first of filtering and validating the measures of heights from the standard water level gauge and the measures of speed and height from the Doppler SW. This database, so validated, is split into two parts. First, part of the data is used to calibrate a rating curve that connects the series of validated levels obtained from the standard water level gauge to the flows obtained from the SW Doppler. Secondly, the other part of the data is used to estimate the capacity of the rating curve already obtained, and to estimate the flows measured by the SW Doppler by using the levels from the standard water level gauge. It was found that the rating curve calibrated for the study site reproduces the data from the SW Doppler with an error that varied according to the hydrographs analyzed. The relative error on the estimation of the complete flood hydrograph varies between 2.51% and 9.87% according to the years, whereas the average relative errors for the peak flows and the flood volumes are 1.44% and 2.11%, respectively. Analysis of the measures shows that the standard water level gauge is more reliable than the SW Doppler because the average percentages of missing values are 4.64% and 20.75%, for the standard water level gauge and the SW Doppler, respectively. However, the SW Doppler has the advantage of accurately generating a large number of flow measures over a wide range of variations, thus calibrating a reliable rating curve. There is therefore clearly a synergy between the two flow estimation approaches. [Journal translation] [ABSTRACT FROM AUTHOR]

The spring flow of the Mackenzie River into its delta drives the breakup ice jamming and consequent flooding and replenishment of the thousands of lakes on the delta plain. Daily flows for related studies are presently furnished by Water Survey of Canada, based on the records of a hydrometric station located close to the delta entrance. The relative proximity of the Beaufort Sea affects the local water surface slope, amplifying uncertainties that are normally associated with under-ice flow estimates. It is shown that gauge-derived spring flows often do not agree with other evidence, such as past discharge measurements, flows at the next upstream gauge, and hydraulic computations for the 2008 event. This appears to result in inconsistencies between spring flow hydrograph and observed severity of ice breakup. Options for improving spring flow estimates are discussed and installation of an auxiliary water-level gauge near Point Separation is recommended as a practical choice. [ABSTRACT FROM AUTHOR]

A simple method for evaluating the discharge at a narrow compound sewer is proposed, based on the entropy concept. The entropy parameter can be obtained from a single pair of mean and maximum velocities at the channel section. This study proved the entropy parameter to be constant in the two real field sites for any hydraulic condition. The linear relation between the mean and maximum velocities was found effective in evaluating the discharge, using the value of the maximum instead of the mean velocity in the channel. The validation of the method was carried out by comparing the estimated results with the measured findings at the field sites. [ABSTRACT FROM AUTHOR]