Accuracy of Annual Volume from Current-Meter-Based Stage Discharges

Clemmens, A. J.; Wahlin, Brian

doi:10.1061/(asce)1084-0699(2006)11:5(489)

Cited by 8 publications

(5 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To a degree, this depends on how much the confidence interval reflects bias in the estimates versus random effects. For the measurement accuracy at the main metering locations, the total (combined) variance was only slightly larger than the variance from the systematic effects (Clemmens and Wahlin 2006). However, for rainfall, storage changes, etc.…”

Section: Imperial Valley Water Balancementioning

confidence: 84%

“…Wahlin et al (1997) conducted a detailed analysis of the accuracy of flow measurement stations for water entering and leaving IID. The methods used were refined by Clemmens and Wahlin (2006 Allen et al (2005) present the results from the WST on estimates of crop evapotranspiration based on the crop coefficient (K c )-reference evapotranspiration (ET o ) approach (K c -ET o ). They compared their estimates to water balance estimates of evapotranspiration from the WST (1998).…”

Section: Imperial Irrigation Districtmentioning

confidence: 99%

“…Analysis of flow measurement accuracy at this site was made by Wahlin et al (1997), following US Geological Survey (USGS) procedures for determining accuracy (Sauer and Meyer 1992). Clemmens and Wahlin (2006) refined these procedures, which gave just slightly higher uncertainty. Measurements at this site produce an extremely accurate estimate of annual water volume.…”

Section: All American Canal Water Balancementioning

confidence: 99%

See 2 more Smart Citations

Accuracy of project-wide water uses from a water balance: a case study from Southern California

Clemmens

2008

Irrig Drainage Syst

View full text Add to dashboard Cite

A detailed water balance was conducted on the Imperial Valley in Southern California for the years 1987 to 1996. The area included all lands within the boundaries defined, including farms, towns, road, etc. This analysis included surface and subsurface inflows, rainfall, surface and subsurface outflows, evaporation, evapotranspiration, municipal and industrial uses, etc. Total water consumption was computed as the remainder in the water balance. The accuracy of this quantity was determined from standard statistical procedures based on the accuracy of the input data. For the Imperial Valley, total water consumption was estimated to within ±4.5%. The various sources of water and destinations were partitioned so that the accuracy of each component could be determined. The method also determines the source of uncertainty through the variance of each measurement. Subsystems were defined so that other quantities of interest could be determined. A canal subsystem water balance was used to determine more accurate estimates of water delivered to farms. A drainage/river subsystem water balance was used to determine the amount of irrigation return flows. Finally, the destinations of irrigation water were delineated and the Irrigation Consumptive Use Coefficient (ICUC) was calculated. The confidence interval, as a 10-year average, was 0.640.70. It was shown that the uncertainty of rainfall and how that water is partition has a significant influence on the accuracy of the estimated water consumption and ICUC.

show abstract

Section: Imperial Valley Water Balancementioning

confidence: 84%

Section: Imperial Irrigation Districtmentioning

confidence: 99%

Section: All American Canal Water Balancementioning

confidence: 99%

See 1 more Smart Citation

Accuracy of project-wide water uses from a water balance: a case study from Southern California

Clemmens

2008

Irrig Drainage Syst

View full text Add to dashboard Cite

show abstract

“…hydrometry electronics automation calibration Palavras-chave: hidrometria eletrônica automação calibração Introduction Velocity-area is the most popular method for flow estimation in water streams, consisting of a discrete integration of velocity, along the cross-section of the channel (Clemmens & Wahlin, 2006;Le Coz et al, 2012;Cohn et al, 2013). Despite the amount of equipment and available technology, current meters are still the widely used devices in various engineering applications, because of the stability and reliability of their measurements (Camnasio & Orsi, 2011).…”

Section: Introductionmentioning

confidence: 99%

Development and evaluation of an automated system for testing current meters

Saretta

Camargo

Botrel

et al. 2016

Rev. bras. eng. agríc. ambient.

View full text Add to dashboard Cite

A B S T R A C TCurrent meters are equipment widely used for estimating flow velocity in rivers and streams. Periodic calibrations of current meters are important to ensure the quality of measurements, but the required testing facilities are complex and only available in a few institutions. However, advances in electronics and automation may contribute to developing simple and reliable calibration systems. Thus, this study aimed to develop an automated system for testing current meters, which consisted of a trapezoidal channel, a step motor, a tow car and a management system, composed of a supervisory application and microprocessed modules to control the motor and the data acquisition. Evaluations of the displacement velocity showed that it matched the reference value up to 1.85 m s -1 for a vertical-axis current meter and 2.3 m s -1 for a horizontal-axis one. The developed system showed reliability during tests, for both current meter movement and data acquisition. The management of the system based on the developed modules and the supervisory application improved its user interface, turning all the procedure into a simple task.Desenvolvimento e avaliação de um sistema automatizado para ensaios de molinetes R E S U M OMolinetes são equipamentos amplamente utilizados para estimativa da velocidade da água em cursos d'água. A calibração periódica de molinetes é necessária para assegurar a qualidade das medições mesmo requerendo infraestrutura complexa para ensaios dos quais poucas instituições dispõem; contudo, os avanços em eletrônica e automação podem contribuir para desenvolver sistemas de calibração simples e confiáveis; assim, desenvolveuse um sistema automatizado para ensaios de molinetes formados por um canal trapezoidal, motor de passo, carro de reboque e um sistema de gerenciamento composto por aplicativo supervisório e módulos microprocessado para controle do motor e aquisição de dados do molinete. Avaliações da velocidade de deslocamento mostraram correspondência com valor de referência até 1,85 m s -1 para um molinete de eixo vertical e 2,3 m s -1 para um de eixo horizontal. O sistema desenvolvido apresentou confiabilidade na execução dos ensaios tanto na movimentação do molinete quanto na aquisição de dados. O gerenciamento do sistema por meio dos módulos desenvolvidos e do aplicativo supervisório facilitou sua utilização por parte do usuário tornando a rotina de calibração bastante simples.

show abstract

“…Habib and Meselhe (2006) used artificial neural networks (ANNs) and nonparametric regression to develop stage-discharge relationships for coastal low-gradient streams. Based on the Jones formula, Petersen-Overleir (2006) proposed a methodology utilizing nonlinear regression as a solution for situations in which the stage-discharge relationship is affected by hysteresis due to unsteady flow; Clemmens and Wahlin (2006) evaluated the accuracy of various methods for finding stage-discharge relationships. Baiamonte and Ferro (2007) presented a new flume for measuring flow discharge in sloping channels and deduced theoretical stagedischarge relationships using dimensional analysis and the self-similarity theory; Guven and Aytek (2009) also reported that Liao and Knight (2007) proposed three analytic stage-discharge formulas for prismatic open channels that are suitable for manual calculation.…”

Section: Introductionmentioning

confidence: 99%

Gene-Expression Programming for the Development of a Stage-Discharge Curve of the Pahang River

Azamathulla

Ghani

Leow

et al. 2011

Water Resour Manage

101

View full text Add to dashboard Cite

This study presents Gene-Expression Programming (GEP), an extension of Genetic Programming (GP), as an alternative approach to modeling the stagedischarge relationship for the Pahang River. The results are compared to those obtained by more conventional methods, i.e., the stage rating curve (SRC) and regression techniques. Additionally, the explicit formulations of the developed GEP models are presented. The performance of the GEP model was found to be substantially superior to both GP and the conventional models.

show abstract

Accuracy of Annual Volume from Current-Meter-Based Stage Discharges

Cited by 8 publications

References 11 publications

Accuracy of project-wide water uses from a water balance: a case study from Southern California

Accuracy of project-wide water uses from a water balance: a case study from Southern California

Development and evaluation of an automated system for testing current meters

Gene-Expression Programming for the Development of a Stage-Discharge Curve of the Pahang River

Contact Info

Product

Resources

About