scholarly journals DESENVOLVIMENTO E AVALIAÇÃO DE DISPOSITIVOS DE CONTROLE DE VAZÃO DERIVADA EM CANAIS DE IRRIGAÇÃO

Irriga ◽  
2007 ◽  
Vol 12 (4) ◽  
pp. 439-455 ◽  
Author(s):  
Camilo De Lelis de Andrade ◽  
Bruno Leite Teixeira Perroni ◽  
Paulo Emílio Pereira de Albuquerque ◽  
Gabriel Roberto Oliveira ◽  
Fernando Falco Pruski ◽  
...  

DESENVOLVIMENTO E AVALIAÇÃO DE DISPOSITIVOS DE CONTROLE DE VAZÃO DERIVADA EM CANAIS DE IRRIGAÇÃO  Camilo de Lelis Teixeira de Andrade1; Bruno Leite Teixeira Perroni2; Paulo Emílio Pereira de Albuquerque1; Gabriel Roberto Oliveira1; Fernando Falco Pruski3; Flávio Aparecido Gonçalves31Embrapa Milho e Sorgo,  Sete Lagoas, MG,  [email protected] de Engenharia, Universidade Federal de Lavras, Lavras, MG3Departamento de Engenharia Agrícola, Universidade Federal de Viçosa, Viçosa, MG  1 RESUMO Em comportas que operam como orifícios retangulares, a variação do nível da água no canal afeta a vazão do orifício, o que provoca erros na estimativa do volume de água derivada. Objetivou-se com esse projeto desenvolver e avaliar dispositivos que possibilitem melhor controle da derivação de água para os lotes. A comporta tipo Módulo de Máscara XX1, comumente utilizada no perímetro,foi aferida no local e suas características hidráulicas comparadas com os dados do fabricante. Três tipos de dispositivos de derivação de água foram desenvolvidos e avaliados, todos baseados na manutenção do nível da água sobre um orifício. No protótipo 1, procura-se manter o nível da água fechando ou abrindo uma portinhola que atua contra o fluxo de entrada de água. No protótipo 2, uma portinhola atua no sentido do fluxo de água como em um carneiro hidráulico. No protótipo 3 o nível da água é mantido constante fechando ou abrindo a saída de um mangote flexível. O módulo de 10 Ls-1 da comporta XX1 apresentou erros de até 20% da vazão nominal quando submetida a níveis de água no canal acima ou abaixo do valor recomendado, conforme reportado no catálogo do fabricante. Dos três protótipos desenvolvidos, o que proporcionou melhor resultado foi de número 3. Testes com o protótipo 3 indicaram que variações máximas de 3,4% na vazão derivada foram observadas para oscilações de30 cm no nível do canal. UNITERMOS: comporta, orifício, medição de água.  ANDRADE, C. L. T.; PERRONI, B. L. T.; ALBUQUERQUE, P. E. P.; PRUSKI, F. F.; OLIVEIRA, G. R. DEVELOPMENT AND EVALUATION OF IRRIGATION CANAL DEVICES FOR WATER TURNOUT CONTROL  2 ABSTRACT In water turnouts that operate by gravity as a rectangular gate, variation on the canal water level affects the estimated discharge to plots. This work objective was to develop and evaluate devices for a better water turnout to plots. An existing commercial gate model XX1, was evaluated in situ and its hydraulic characteristics compared to manufacturer´s data. Three types of water turnout devices were developed and evaluated, all of them based on the principle of maintaining a constant water level over an orifice. In prototype 1, water level is maintained by opening or closing a gate against the inlet water flow. In prototype 2, the gate is positioned in the flow direction, like in a water hammer. In prototype 3, water level is kept by opening or closing a flat hose outlet. The 10 Ls-1 module of a XX1 gate causes errors of up to 20% of the nominal discharge when operated under water levels above or below the recommended value by the manufacturer. Considering three developed prototypes, a better water turnout control was obtained with prototype 3. Tests with prototype 3 indicated that a maximum of 3.4% of the derived discharged was observed for fluctuations of up to30 cm on the canal level.  KEYWORDS: gate, orifice, water measurement.

2020 ◽  
Vol 2 (2) ◽  
pp. 178
Author(s):  
Srie Wulandarie

AbstractThe purpose of this study was to determine the hydrodynamic model of the river so that can know the capacity of the river to accommodate the incoming water flow. The simulation models can be used in structural mitigation plan as an attempt to prevent flooding in the future. The application program used to create hydrodynamic models that Infoworks River Simulation integrated with GIS. Data cross-section of the river as much as 39 points inputted into Infoworks River Simulation program. Furthermore, the discharge input the Saddang River and the Mata Allo River to determine variations in water level at each cross-section. The results of this study showed an average increase in water level of the Saddang  and Mata Allo River in the event of the maximum discharge of 2.59 meters. Sectional increased water levels are all cross sections along the Saddang and Mata Allo River Saddang used in modeling the variation of the rise in water level of 0.8 to 5.39 meters.


1994 ◽  
Vol 40 (135) ◽  
pp. 293-304 ◽  
Author(s):  
Andrew G. Fountain

AbstractBoreholes were drilled in South Cascade Glacier to investigate the hydraulics of subglacial water flow. Results indicate that subglacial water pressures are generally close to local ice-overburden pressures and that a subglacial debris layer probably exists. Calculations indicate that the range of hydraulic conductivity of this layer is 10−7-10−4m−1. The borehole water levels generally increased during the ablation season and may be caused by a seasonal evolution in the permeability of the debris layer. Water in the debris layer drains to a subglacial conduit, the existence of which is inferred by large diurnal variations in the water level of one borehole. These levels commonly reached the bottom of the glacier, indicating near-atmospheric pressures in the conduit.


2009 ◽  
Vol 60 (9) ◽  
pp. 2281-2289 ◽  
Author(s):  
L. S. Nguyen ◽  
B. Schaeli ◽  
D. Sage ◽  
S. Kayal ◽  
D. Jeanbourquin ◽  
...  

Combined sewer overflows and stormwater discharges represent an important source of contamination to the environment. However, the harsh environment inside sewers and particular hydraulic conditions during rain events reduce the reliability of traditional flow measurement probes. In the following, we present and evaluate an in situ system for the monitoring of water flow in sewers based on video images. This paper focuses on the measurement of the water level based on image-processing techniques. The developed image-based water level algorithms identify the wall/water interface from sewer images and measure its position with respect to real world coordinates. A web-based user interface and a 3-tier system architecture enable the remote configuration of the cameras and the image-processing algorithms. Images acquired and processed by our system were found to reliably measure water levels and thereby to provide crucial information leading to better understand particular hydraulic behaviors. In terms of robustness and accuracy, the water level algorithm provided equal or better results compared to traditional water level probes in three different in situ configurations.


2021 ◽  
Vol 13 (11) ◽  
pp. 2196
Author(s):  
Frédéric Frappart ◽  
Fabien Blarel ◽  
Ibrahim Fayad ◽  
Muriel Bergé-Nguyen ◽  
Jean-François Crétaux ◽  
...  

Radar altimetry is now commonly used to provide long-term monitoring of inland water levels in complement to or for replacing disappearing in situ networks of gauge stations. Recent improvements in tracking and acquisition modes improved the quality the water retrievals. The newly implemented Open Loop mode is likely to increase the number of monitored water bodies owing to the use of an a priori elevation, especially in hilly and mountainous areas. The novelty of this study is to provide a comprehensive evaluation of the performances of the past and current radar altimetry missions according to their acquisition (Low Resolution Mode or Synthetic Aperture Radar) and tracking (close or open loop) modes, and acquisition frequency (Ku or Ka) in a mountainous area where tracking losses of the signal are likely to occur, as well as of the recently launched ICESat-2 and GEDI lidar missions. To do so, we evaluate the quality of water level retrievals from most radar altimetry missions launched after 1995 over eight lakes in Switzerland, using the recently developed ALtimetry Time Series software, to compare the performances of the new tracking and acquisition modes and also the impact of the frequency used. The combination of the Open Loop tracking mode with the Synthetic Aperture Radar acquisition mode on SENTINEL-3A and B missions outperforms the classical Low Resolution Mode of the other missions with a lake observability greater than 95%, an almost constant bias of (−0.17 ± 0.04) m, a RMSE generally lower than 0.07 m and a R most of the times higher than 0.85 when compared to in situ gauge records. To increase the number of lakes that can be monitored and the temporal sampling of the water level retrievals, data acquired by lidar altimetry missions were also considered. Very accurate results were also obtained with ICESat-2 data with RMSE lower than 0.06 and R higher than 0.95 when compared to in situ water levels. An almost constant bias (0.42 ± 0.03) m was also observed. More contrasted results were obtained using GEDI. As these data were available on a shorter time period, more analyses are necessary to determine their potential for retrieving water levels.


Author(s):  
Paulo Henrique Costa ◽  
Eric Oliveira Pereira ◽  
Philippe Maillard

Satellite altimetry is becoming a major tool for measuring water levels in rivers and lakes offering accuracies compatible with many hydrological applications, especially in uninhabited regions of difficult access. The Pantanal is considered the largest tropical wetland in the world and the sparsity of <i>in situ</i> gauging station make remote methods of water level measurements an attractive alternative. This article describes how satellites altimetry data from Envisat and Saral was used to determine water level in two small lakes in the Pantanal. By combining the water level with the water surface area extracted from satellite imagery, water volume fluctuations were also estimated for a few periods. The available algorithms (retrackers) that compute a range solution from the raw waveforms do not always produce reliable measurements in small lakes. This is because the return signal gets often “contaminated” by the surrounding land. To try to solve this, we created a “lake” retracker that rejects waveforms that cannot be attributed to “calm water” and convert them to altitude. Elevation data are stored in a database along with the water surface area to compute the volume fluctuations. Satellite water level time series were also produced and compared with the only nearby <i>in situ</i> gauging station. Although the “lake” retracker worked well with calm water, the presence of waves and other factors was such that the standard “ice1” retracker performed better on the overall. We estimate our water level accuracy to be around 75 cm. Although the return time of both satellites is only 35 days, the next few years promise to bring new altimetry satellite missions that will significantly increase this frequency.


Geophysics ◽  
2021 ◽  
pp. 1-46
Author(s):  
Min Zhang ◽  
Ziwei Liu ◽  
Qiong Wu ◽  
Yuntian Teng ◽  
Xiaotong Zhang ◽  
...  

Inter-seasonal and geodynamics-related gravity changes are important geoscientific signals that are extractable from gravimeter observations after deducing background information as local hydrology gravity effect. With two superconducting gravimeters (SGs, OSG-053 and iGrav-007) located in different tectonic units, continuous Global Navigation Satellite System data, and AG observations, Wuhan (China) is an ideal location for investigating the effects of gravity resulting from significant local hydrology mass variations. We processed ∼26 months of gravity data collected from the SGs in Wuhan and obtain residuals of -40 nm.s2 for OSG-053 and 100 for iGrav-007. The hydrological observations show an estimated gravity increase of 42 nm.s2 near iGrav-007, which mainly resulted from the increased unconfined water level with an aquifer-specific yield of approximately 0.1. However, the gravity changes around OSG-053 are mainly from soil moisture and reach -90 nm.s2. The soil type, thickness and water content parameters were obtained from hydrogeological survey and drilling data. The deep confined water level rose by 2.5 m, which introduced a 1 nm.s2 gravity variation with a specific storage about 0.00001 from field unsteady flow pumping test. The modeled gravity is approximately -40 nm.s2 around OSG-053 and 90 around iGrav-007, in accordance with the observed gravity variations. The difference in gravity changes between the two SG observations can be explained by different local water storage environments. Our results suggest that unconfined and soil water significantly impact the in-situ gravimetry, which indicates that further detailed hydrogeological surveys are required. A combined investigation of gravity and water levels can be a useful approach to monitor aquifer storage conditions and groundwater management.


2015 ◽  
Vol 19 (10) ◽  
pp. 4345-4364 ◽  
Author(s):  
C. Schwatke ◽  
D. Dettmering ◽  
W. Bosch ◽  
F. Seitz

Abstract. Satellite altimetry has been designed for sea level monitoring over open ocean areas. However, for some years, this technology has also been used to retrieve water levels from reservoirs, wetlands and in general any inland water body, although the radar altimetry technique has been especially applied to rivers and lakes. In this paper, a new approach for the estimation of inland water level time series is described. It is used for the computation of time series of rivers and lakes available through the web service "Database for Hydrological Time Series over Inland Waters" (DAHITI). The new method is based on an extended outlier rejection and a Kalman filter approach incorporating cross-calibrated multi-mission altimeter data from Envisat, ERS-2, Jason-1, Jason-2, TOPEX/Poseidon, and SARAL/AltiKa, including their uncertainties. The paper presents water level time series for a variety of lakes and rivers in North and South America featuring different characteristics such as shape, lake extent, river width, and data coverage. A comprehensive validation is performed by comparisons with in situ gauge data and results from external inland altimeter databases. The new approach yields rms differences with respect to in situ data between 4 and 36 cm for lakes and 8 and 114 cm for rivers. For most study cases, more accurate height information than from other available altimeter databases can be achieved.


Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2063
Author(s):  
Yuan Gao

The movement of fluid particles about historic subsurface releases is often governed by dynamic subsurface water levels. Motivations for tracking the movement of fluid particles include tracking the fate of subsurface contaminants and resolving the fate of water stored in subsurface aquifers. This study provides a novel method for predicting the movement of subsurface particles relying on dynamic water-level data derived from continuously recording pressure transducers. At least three wells are needed to measure water levels which are used to determine the plain of the water table. Based on Darcy’s law, particle flow pathlines at the study site are obtained using the slope of the water table. The results show that hydrologic conditions, e.g., seasonal transpiration and precipitation, influence local groundwater flow. The changes of water level in short periods caused by the hydrologic variations made the hydraulic gradient diversify considerably, thus altering the direction of groundwater flow. Although a range of groundwater flow direction and gradient with time can be observed by an initial review of water levels in rose charts, the net groundwater flow at all field sites is largely constant in one direction which is driven by the gradients with higher magnitude.


2002 ◽  
Vol 4 (4) ◽  
pp. 265-280 ◽  
Author(s):  
Björn Sohlberg ◽  
Mats Sernfält

This paper deals with modelling and identification of a river system using physical insights about the process, experience of operating the system and information about the system dynamics shown by measured data. These components together form a linear model structure in the state space form. The inputs of the prospective model are physical variables, which are not directly measured. However, the model inputs can be found by a nonlinear transformation of measured variables. Unknown parameters of the model are estimated from measured data. The modelling work focuses on the principle of parsimony, which means the best model approach is the simplest one that fit the purpose of the application. The goal of the model is to control the water level of the river, where the water flow is mainly determined by the demand for energy generation produced by the hydropower stations along the river. The energy requirement increases in the morning and decreases in the evening. These flow variations, caused by the energy demand, have to be compensated by controlling the power plants downstream, in such a way that the water level between the power stations is guaranteed. Simulation of the control system by using an adaptive model predictive controller shows that the water levels vary less and can be maintained at a higher level than during manual control. This means that more electric power can be produced with the same amount of water flow.


2015 ◽  
Vol 12 (5) ◽  
pp. 4813-4855 ◽  
Author(s):  
C. Schwatke ◽  
D. Dettmering ◽  
W. Bosch ◽  
F. Seitz

Abstract. Satellite altimetry has been designed for sea level monitoring over open ocean areas. However, since some years, this technology is also used for observing inland water levels of lakes and rivers. In this paper, a new approach for the estimation of inland water level time series is described. It is used for the computation of time series available through the web service "Database for Hydrological Time Series over Inland Water" (DAHITI). The method is based on a Kalman filter approach incorporating multi-mission altimeter observations and their uncertainties. As input data, cross-calibrated altimeter data from Envisat, ERS-2, Jason-1, Jason-2, Topex/Poseidon, and SARAL/AltiKa are used. The paper presents water level time series for a variety of lakes and rivers in North and South America featuring different characteristics such as shape, lake extent, river width, and data coverage. A comprehensive validation is performed by comparison with in-situ gauge data and results from external inland altimeter databases. The new approach yields RMS differences with respect to in-situ data between 4 and 38 cm for lakes and 12 and 139 cm for rivers, respectively. For most study cases, more accurate height information than from available other altimeter data bases can be achieved.


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