Parshall Flume Research Articles

Performance Evaluation of Woybo Irrigation Scheme: Wolaita Zone, Southern Ethiopia

Performance evaluation of irrigation scheme is vital for realizing the present status and identifying the area for improvement. The study was conducted in Woybo irrigation scheme which is located in Boloso Sore district, Wolaita zone, Southern Ethiopia. This study was aimed to evaluate the performance of Woybo irrigation scheme with internal performance indicators. A total of nine demonstrating farmers' fields were selected from three canal reaches (head, middle, and tail) through purposive sampling. Primary and secondary data were collected, recorded, and analyzed. To measure the water applied to each experimental field, Parshall flume was installed, and soil samples were taken to determine soil texture, field capacity, permanent wilting point, and soil moisture content before and after each irrigation event at regular soil depth intervals. The results revealed that the mean conveyance efficiency was 60.85% and the application efficiency was 48.53%. Water distribution uniformity, deep percolation, and storage efficiencies were 84.56%, 51.47%, and 85.22%, respectively. However, the overall irrigation efficiency was found to be 29.53%, which was poorly performed due to inadequate water application, ineffective field water management, and low efficiency in water delivery systems. The main factors contributing to the poor water delivery performance included failures in water regulating gates, leakages, and siltation of canals. To address these problems, recommendations are made such as improvements in water application techniques should be implemented, through proper irrigation scheduling, water conservation practices, surge irrigation techniques, and providing extension support, training, and experience sharing. Additionally, maintenance and lining of earthen canals are necessary, along with the replacement and repair of leakages and broken water regulating and controlling structures. These measures can help to upgrade water delivery efficiency and improve the overall performance of the irrigation scheme.

Performance evaluation of a nonstandard Parshall flume and comparison of experimental techniques for its verification in a drinking water treatment plant

ABSTRACT This article investigates a nonstandard Parshall flume (Pf) to assess the impact of engineering deficiencies on flow rate (Q) estimation and compare experimental techniques for evaluating its performance in Q quantification and velocity gradient (G) appraisal during rapid mixing. Considering construction and instrumentation issues in the studied Pf, Q estimates were 10% lower than those derived from the standard rating curve (SRC), with 9% of this discrepancy attributable to the high placement of the stilling well scale and 1% to the position of the connecting pipe to the gauging section. When contrasting Q estimates from the SRC to the current rating curve in use and a set of rating curves fitted using salt dilution gauging (SDG), acoustic Doppler velocimetry (ADV), and numerical modeling (CFD), the average differences were −10.2, −8.3, −2.2, and 0.2%, respectively, for the current rating curve in use and those fitted to ADV, SDG, and CFD data. Considering only the instrumental measuring techniques, the SDG exhibited superior fittings (R2 = 0.99), followed by ADV (R2 = 0.95). Calculations of G aligned (9.3%) with CFD estimates support these methods as reliable tools for evaluating and verifying nonstandard Pf performance.

Response of Durum Wheat to Deficit Irrigation

Deficit irrigation trial has been conducted to see the response of durum wheat to the extent of deficit irrigation at Debre Zeit research center for three successive seasons from 2016 to 2018. Establishment irrigations were given for all plots after swing and irrigation water application events were monitored using long term meteorological data and soil moisture readings. Irrigation water application depths (amount of water applied) were calculated from cumulative crop evapotranspiration (ETc) values in a given period and plots were irrigated with depths that was replenish 100 %, 75%, and 50 % of the cumulative ETc as per the treatment to be applied. Measured amount of irrigation water applied to every plot measured by using 3 inch Parshall flume. Results indicated those grain yields significantly affected by deficit irrigation levels and furrow irrigation methods. The highest mean grain yield of 5.8 t/ha attained from 75% ETc irrigation level with alternate furrow irrigation method while the lowest mean yield of 3.989 t/ha was obtained from treatment irrigated with 50% ETc and conventional furrow irrigation method. Therefore, based on the current findings, the highest grain yield was obtained at 75% ETc with alternate furrow irrigation system while the highest WUE was recorded at irrigating 100% ETc with alternate furrow system.

Avaliação da eficiência na utilização de cortinas de turbidez para retenção de sólidos suspensos realizada em escala piloto

ABSTRACT This study aims to stimulate debate on the behavior of geotextile blankets in retaining suspended solids and to offer subsidies for further research. By means of a simple and objective approach, the results of a pilot-scale experiment are presented, with the objective of suggesting the use of containment barriers as a simple and inexpensive technique for raw water pre-filtration. Due to the growing demand for treated water and a marked decrease in the quality of the water available for catchment, it becomes necessary to increase the dosage of chemicals used in the treatment. Consequently, this influences not only the costs but also the characteristics of the waste generated in the process, since the nature and quantity of the sludge depend, among other factors, on the turbidity and the dosage of coagulant chemicals. The experiment was carried out using an acrylic channel where two adequately spaced geotextile blanket barriers were positioned, with raw water from the Parshall flume being pumped into the channel and, after passing through the barriers, returned by gravity to the flume and then sent for treatment. The affluent flow was maintained at 3.5 L/min and the blankets used had a weight of 170.0 and 420.0 g/m2, respectively. The results were not sufficient to conclude whether or not there is a relationship between the average raw water turbidity and the average turbidity reduction by the system. However, they show good chances of reducing sludge generation in water treatment plants receiving raw water pre-filtered by the proposed system, even with the average turbidity reduction considered low.

Soft computing-based model development for estimating the aeration efficiency through Parshall flume and Venturi flumes

Soft computing-based model development for estimating the aeration efficiency through Parshall flume and Venturi flumes

Environmental Quality Management through Parshall Flume Aeration Efficiency Modelling

Environmental Quality Management through Parshall Flume Aeration Efficiency Modelling

Montana Flume Aeration Performance Evaluation with Machine Learning Models

Montana flume is derived from Parshall flume by eliminating diverging part and throat. The mass transfer of oxygen from the atmosphere into the water is known as aeration. The dissolved oxygen (D.O.) concentration in the water body determines water quality. The experiment was performed on six different Montana flumes fixed in a tilting prismatic rectangular channel. Experimental observations were used to develop classical and machine learning models to predict Montana flume aeration efficiency. The developed models are namely multi nonlinear regression (MNLR), adaptive neuro-fuzzy inference system (ANFIS), and artificial neural network (ANN). The models were tested, and the results show that all these three developed models perform very well. However, ANN gives better results than other models as it has the highest cc and lowest rmse values. According to the sensitivity analysis results, the Reynolds number (Re) was the most crucial input element in determining the aeration efficiency of the Montana flume in the case of dimensionless datasets. However, discharge per unit width (q) is found to be of relative significance in the case of dimensional datasets.

Application of tannin-based coagulant for high-range turbidity surface water clarification

Abstract This study aimed to evaluate the performance of a tannin-based coagulant in clarifying drinking water from a high-range turbidity river and characterizing the sludge. Tanfloc MTH product was selected for this investigation. The study site was surface water located in southern Brazil (Caveiras River, Brazil). Samples were collected just before the Parshall flume in the municipal water treatment plant in Lages (Brazil) for nine months, at least once a week. Jar testing evaluated turbidity removal, alkalinity consumption, optimal coagulant dosage, and settling velocity. After flocculation and settling, the sludge generated from the jar test was submitted to metal and thermogravimetric analyses. The use of tannin reduced the average water turbidity from 26.1 ± 56.1 to 0.94 ± 0.26 NTU, apparent color from 145 ± 190 to 3 ± 3 Pt-Co, and there was no variation in the pH. Additionally, the settling velocity of the flocs reached a maximum turbidity removal at 3.5 cm·min−1. Furthermore, the metal concentrations in the sludge showed a majority of aluminum and iron, and thermogravimetric analysis revealed 64% weight loss. In conclusion, Tanfloc presented the potential to be used in surface water clarification from the Caveiras river, and the extensive turbidity range observed during this study did not affect the operational stability.

Evaluating the performance of small‐scale irrigation schemes in subhumid Ethiopian highlands

AbstractThis study was conducted to evaluate the performance of two small‐scale irrigation (SSI) schemes in the subhumid Ethiopian highlands. Water application at the farm level and flow velocity along the main canal were monitored using a Parshall flume and current meter, respectively. The infiltration was measured at the head, middle and tail of the scheme within the command area using a double‐ring infiltrometer. Soil samples were collected using an auger up to 60 cm in depth. Climatic and agronomic data were supplied to the crop water assessment tool (CROPWAT) to determine crop water requirements. The results showed that the average conveyance efficiency for the lined main canal was 90% and 92% for the Mugie and Fesas SSI schemes, respectively. The conveyance efficiency for the unlined main canal was in the order of 86% and 87% for the Mugie and Fesas SSI schemes, respectively. On the other hand, the average application efficiency and overall efficiency were found to be 56% and 51%, respectively, with a storage efficiency of 50% for the Mugie irrigation scheme. Similarly, the overall, application and storage efficiencies were 50%, 54% and 56%, respectively, for the Fesas irrigation scheme. Failure of operating gates, canal siltation and leakage through the main canals were the main causes of poor performance.

Hydraulic characteristics of the Parshall flume entrance wingwall: Numerical simulation and test

AbstractThe Parshall flume is a common open channel water‐measuring facility that is widely used in hydrological monitoring, agricultural irrigation and municipal water supply. In engineering applications, there is no clear requirement for the form of the wingwalls connecting the channel and Parshall flume. Therefore, it has different effects on flow measurement accuracy, flow velocity distribution and hydraulic characteristics. To standardize its construction requirements, a wingwall form with high flow measurement accuracy is evaluated. Computational fluid dynamics (CFD) numerical simulations and hydraulic experiments have shown the influence of different wingwalls on hydraulic characteristics. The governing test parameters include wingwall forms, incoming flow and degree of submergence. By measuring water surface fluctuation, streamline distribution and flow measurement error, the effects of different wingwall forms on flow measurement accuracy and hydraulic characteristics were evaluated. The results showed that the fluctuation of the water surface is affected by the boundary conditions. Layout I has the highest flow measurement accuracy and has an arc‐shaped wingwall with a radius of 1.5 m. By comparing the results of the tests and simulations, the average error is 3%. The results showed that the hydrodynamic model of the Parshall flume can provide a theoretical basis for the design and development of the measurement structure in the future.

Capítulo 7: Diseño de canaleta Parshall

I. INTRODUCTIONThe Parshall Flume, which was invented in 1920 by R. Parshall, is mostly used in wastewater and crop supply. Utilizing equations, Parshall established dimensions that fit the design, one of the advantages is the conversion of position energy to velocity energy since in other measurement structures there are minimum energy losses in this one it does not allow sedimentation.
 The structuring of the project is adhered to by different models that define its behavior and limit its use. This is the case of an approach length of the channel entrance, which is nothing more than a primary distance for the action of the flow within the channel. Throughout history, some studies were conducted in an attempt to establish an approximate and realistic value of the length at the time of measurements, but the theories put forward were lost. Some people link this length with the narrowing of the gorge, and others suggest flow conditions before entering the flume.
 For the development of the project established with its respective objectives, the respective structuring was carried out: For the measurement, the points already established in the field will be taken with the help of a total station, GPS, to verify the respective measurements of the Parshall flume. For the calculations and the design, the points will be introduced in the civil 3D to be able to verify if the points taken are the correct ones and what distances they have between them, through this, we can apply different methods to be able to verify the design that has this Parshall flume. For the evaluation and layout of the gutter, if it is the case, we will carry out a layout in plan with the data already calculated in the office and we will evaluate the situation in which it is so that we can apply a possible solution so that a defect does not occur.
 In this report, we focus on the design and redesign of a hydraulic irrigation channel where we find a Parshall section, which has the function of measuring the flow found in that section. The measurements found in the field can be verified in the office using formulas and software to verify if the data are correct, if so we can say that it is well designed, otherwise we will look for a possible solution by doing a field study.

Effect of Drip Irrigation and Inter Cropping Systems on Growth Characters of Maize

Aims: The main aim of the study is to reduce the irrigation quantity for maize and intercrop adds extra value to the sole crop by generating additional income to the farmers.
 Study Design: Factorial Randomised Block Design (FRBD).
 Place and Duration of Study: Eastern block farm, Tamil Nadu Agricultural University, Coimbatore during summer and Kharif 2021.
 Methodology: Maize as a sole crop and inter crop was grown under drip and flooded conditions. To quantify the irrigation with different set of irrigation as treatments (75% PE, 100% PE and 125% PE) was followed. Irrigation under flooded conditions was quantified using parshall flume. Different inter crops like Lab Lab, Green gram, Black Gram and Cow pea was raised within the rows of maize. The duration of inter crops was less than 60 days than that of maize.
 Results: During its peak cob formation stage (61-90 days), the quantity of water applied to the plant was higher with 125 % PE (205858.8 l/day) followed by 100% PE (123515.3 l/day) and 75 % PE (164687.1 l/day). The higher plant height was observed with 280.5 cm in Maize + Lab Lab followed by black gram, green gram and cowpea. Irrigation level varied significantly with 100% open pan evaporation on plant growth (254.8 cm) followed by 75% open pan evaporation. Interaction effect was significant in Maize + Lab Lab cropping system alone, irrespective of the irrigation treatments (75, 100, 125 % PE and flooding).
 Conclusion: Water requirement with the month and stage wise during the crop growth clearly indicates that the minimum amount of water is required for the crop growth and development.

Application of Numerical and Experimental Modeling to Improve the Efficiency of Parshall Flumes: A Review of the State-of-the-Art

One of the primary steps in managing the flow in an open channel is determining its properties. Empirical equations are developed to provide further information regarding the flow in open channels. Obtaining such experimental equations is expensive and time consuming; therefore, alternative solutions have been sought. Over the last century, the Parshall flume, a static measuring device with no moving parts, has played a significant role in measuring the flow in open channels. Many researchers have focused their interest on studying the application of Parshall flumes in various fields like irrigation and wastewater management. Although various scholars used experimental results to enhance the rating equation of the Parshall flume, others used an alternative source of data to recalibrate the height–discharge relation equation using numerical simulation. Computational Fluid Dynamic (CFD) software is becoming popular nowadays as computing hardware has advanced significantly within the last few decades, making it possible to go beyond the limited resolution that was experienced in the past. Multiple CFD models, depending on their availability, either open-source or commercially licensed, have been used to perform numerical simulations on different configurations of flumes, especially Parshall flumes, to produce water level results. Regarding various CFD tools that have been used, i.e., FLOW-3D, Ansys Fluent, or OpenFOAM, after precise calibration with experimental data, it has been determined that the output is reliable and can be implemented to the actual scenarios. The benefit of using this technique to produce results is the ability of the CFD approach to adjust the initial conditions, like flow velocity or structural geometry, where necessary. With respect to channel size and the condition of the site where the flume is located, the choices are narrowed to the specific Parshall flume suitable to the situation. It is not always possible to select the standard Parshall flume; therefore, engineers provide some modification to the closest flume size and provide a new rating curve to produce accurate flowrates. This review has been performed on the works of a number of scholars who targeted the application of numerical simulation and physical experimental data in Parshall flumes to either enhance the existing rating equation or propose further modification to the structure’s geometry.

Numerical Simulation of Flow in Parshall Flume Using Selected Nonlinear Turbulence Models

This study uses a computational fluid dynamics (CFD) approach to simulate flows in Parshall flumes, which are used to measure flowrates in channels. The numerical results are compared with the experimental data, which show that choosing the right turbulence model, e.g., v2−f and LC, is the key element in accurately simulating Parshall flumes. The Standard Error of Estimate (SEE) values were very low, i.e., 0.76% and 1.00%, respectively, for the two models mentioned above. The Parshall flume used for this experiment is a good example of a hydraulic structure for which the design can be more improved by implementing a CFD approach compared with a laboratory (physical) modeling approach, which is often costly and time-consuming.

General free-flow discharge equation for Parshall flumes

Standard Parshall flumes are widely used as in-line flow measurement structures in open channels and irrigation projects. The calibration of flow measurement structures is an important issue in practical applications. At present, free-flow Parshall flumes have separate empirical discharge equations for each nominal flume size, ranging from 1 inch to 50 ft (0.0254–15.24 m). In this study, using dimensional analysis and 420 data points generated from the original rating equations of 21 standard Parshall flume sizes, different dimensionally homogeneous equations were developed to calculate discharge values in Parshall flumes. The results showed that the throat width, the contraction ratio and the Reynolds number are key parameters for deducing a generic discharge equation. A general calibration discharge equation was developed for free-flow conditions for any Parshall flume in the range of 21 standard sizes and a specified contraction ratio of 0.15–0.82 according to the original design criteria. The proposed equation also enables computation of the discharge of Parshall flumes with custom and intermediate sizes. Compared with the original values, the average error in the discharges estimated using the proposed unified discharge equation for all flume sizes was found to be 0.95%.

Evaluating Parshall flume aeration with experimental observations and advance soft computing techniques

Evaluating Parshall flume aeration with experimental observations and advance soft computing techniques

Effect of decision variables on yield and water productivity of onion under conventional furrow irrigation system in bako woreda, Ethiopia

Flow rate and furrow length are the main irrigation decision variables currently affecting yield and water productivity at farm level. Improper selection of these variables produces an over use of water and loss in crop production. The general objective was to investigate the effect of decision variables on yield and water productivity of onion under conventional furrow irrigation system, with specific objective to analyze the effect of flow rate, furrow length and their interaction on yield and water productivity of onion. The field experiment was laid out in randomized complete block design with factorial arrangement of three levels of flow rate (0.7, 0.98 and 1.3 L/S) and three levels of furrow length (25, 35 and 50 m) with three replications. Inflow out flow method was used to determine the infiltration characteristics of the soil and Irrigation depth was controlled by using 3-inch Parshall flume. The maximum non-erosive flow rate to the experimental site was fixed through design equation considering soil textural class and furrow bed slope. Effect of furrow length and flow rate on yield and water productivity of the onion were used for evaluation. Their analyses indicated that effect of furrow length and their interaction with flow rate on yield were not significant (p<0.05). However, the flow rate showed highly significant (p<0.01) effect on yield of onion. The ranges of mean yield gained from furrow length and flow rate were F1 (14.75 ton ha-1) to F3 (15.96 ton ha-1) and Q1 (13.59 ton ha-1) to Q3 (19.69 ton ha-1), respectively. The effect of furrow length on crop water use efficiency and field water use efficiency was not significant (p<0.05). However, the flow rate has showed highly significant (p<0.01) effect on crop water use efficiency and field water use efficiency. The range of mean crop water use efficiency and field water use efficiency from furrow length and flow rate were F1 (33.65 kg/ha/mm) to F3 (36.41 kg/ha/mm) and Q1 (30.99 kg/ha/mm) to Q3 (38.65kg/ha/mm) and F1 (2.06 kg/m3) to F3 (2.23 kg/m3) and Q1 (1.89 kg/m3) to Q3 (2.36 kg/m3), respectively. Therefore, it can be concluded that a furrow length of 50 m is suitable to use 1.3 L/S of flow rate for better onion yield and water productivity under similar soil type of study area.
 Int. J. Agril. Res. Innov. Tech. 11(1): 92-100, June 2021

Prediction of aeration efficiency of Parshall and Modified Venturi flumes: application of soft computing versus regression models

AbstractIn this study, the potential of soft computing techniques, namely Random Forest (RF), M5P, Multivariate Adaptive Regression Splines (MARS), and Group Method of Data Handling (GMDH), was evaluated to predict the aeration efficiency (AE20) of Parshall and Modified Venturi flumes. Experiments were conducted for 26 various Modified Venturi flumes and one Parshall flume. A total of 99 observations were obtained from experiments. The results of soft computing models were compared with regression-based models i.e., with multiple linear regression (MLR) and multiple nonlinear regression (MNLR). Results of the analysis revealed that the MARS model outperformed other soft computing and regression-based models for predicting AE20 of Parshall and Modified Venturi flumes with Pearson's correlation coefficient (CC) = 0.9997, and 0.9992, and root mean square error (RMSE) = 0.0015, and 0.0045 during calibration and validation periods, respectively. Sensitivity analysis was also carried out by using the best executing MARS model to assess the effect of individual input variables on AE20 of both flumes. Obtained results on sensitivity examination indicate that the oxygen deficit ratio (r) was the most effective input variable in predicting the AE20 of Parshall and Modified Venturi flumes.

Machine learning model development for predicting aeration efficiency through Parshall flume

This study compares several advanced machine learning models to obtain the most accurate method for predicting the aeration efficiency (E20) through the Parshall flume. The required dataset is obtained from the laboratory tests using different flumes fabricated in National Institute Technology Kurukshetra, India. Besides, the potential of K Nearest Neighbor (KNN), Random Forest Regression (RFR), and Decision Tree Regression (DTR) models are evaluated to predict the aeration efficiency. In this way, several input combinations (e.g. M1-M15) are provided using the laboratory parameters (e.g. W/L, S/L, Fr, and Re). Different predictive models are obtained based on those input combinations and machine learning models proposed in the present study. The predictive models are assessed based on several performance metrics and visual indicators. Results show that the KNN-M11 model (), which includes W/L, S/L, and Fr as predictive variables outperforms the other predictive models. Furthermore, an enhancement is observed in KNN model estimation accuracy compared to the previously developed empirical models. In general, the predictive model dominated in the present study provides adequate performance in predicting the aeration efficiency in the Parshall flume.

The Removal of Residual Concentration of Hazardous Metals in Wastewater from a Neutralization Station Using Biosorbent-A Case Study Company Gutra, Czech Republic.

This article deals with the possibility of using a biosorbent in the form of a mixture of cones from coniferous trees to remove the residual concentration of hazardous metals contained in hazardous waste, which is disposed of in a neutralization station. The efficiency of the tested biosorbent in removing Ni, Zn, Cu, and Fe was monitored here. Laboratory research was carried out before the actual testing of the biosorbent directly in the operation of the neutralization station. With regard to the planned use of the biosorbent in the operational test, the laboratory experiments were performed in a batch mode and for the most problematic metals (Ni and Zn). The laboratory tests with real wastewater have shown that the biosorbent can be used to remove hazardous metals. Under the given conditions, 96% of Ni and 19% of Zn were removed after 20 min when using NaOH activated biosorbent with the concentration of 0.1 mol L−1. The inactivated biosorbent removed 93% of Ni and 31% of Zn. The tested biosorbent was also successful during the operational tests. The inactivated biosorbent was applied due to the financial costs. It was used for the pre-treatment of hazardous waste in a preparation tank, where a significant reduction in the concentration of hazardous metals occurred, but the values of Ni, Cu, and Zn still failed to meet the emission limits. After 72 h, we measured 10 mg L−1 from the original 4,056 mg L−1 of Ni, 1 mg L−1 from the original 2,252 mg L−1 of Cu, 1 mg L−1 from the original 4,020 mg L–1 of Zn, and 7 mg L−1 from the original 1,853 mg L−1 of Fe. However, even after neutralization, the treated water did not meet the emission limits for discharging into the sewer system. The biosorbent was, therefore, used in the filtration unit as well, which was placed in front of the Parshall flume. After passing through the filtration unit, the concentrations of all the monitored parameters were reduced to a minimum, and the values met the prescribed emission limits. The biosorbent was further used to thicken the residual sludge in the waste pre-treatment tank, which contributed to a significant reduction in the overall cost of disposing of residual hazardous waste. This waste was converted from liquid to solid-state.