scholarly journals Calibration of Manning’s roughness in non-instrumented rural basins using a distributed hydrological model

DYNA ◽  
2019 ◽  
Vol 86 (210) ◽  
pp. 164-173
Author(s):  
Carlos Andrés Caro Camargo ◽  
Oscar Fabián Pacheco Merchán ◽  
Hans Paul Sánchez Tueros
Keyword(s):  
Hydrological Model ◽  
Numerical Study ◽  
Research Work ◽  
Roughness Coefficient ◽  
Distributed Hydrological Model ◽  
The Standard Model ◽  
Saint Venant Equations ◽  
Volume Method ◽  
Best Fit ◽  
Selection Of

The purpose of this research work was to calibrate the Manning's roughness coefficient in rural non-instrumented basins using a distributed hydrological model. The process consisted of the selection of several basins with vegetal cover of forests and grasslands, and its subsequent experimental numerical study, in which the hydrological response hydrograph of each reference basin was obtained from the HEC-HMS software and the hydrograph to be calibrated was the Iber software, which is a hydrodynamic model based on the two-dimensional Saint Venant equations, solved by the finite volume method. Once the calibration process was carried out, the roughness coefficients with the best fit for each basin were identified with increases in precipitation, identifying the limitations of these values and the standard model used.

scholarly journals Dynamic Manning's roughness coefficients for hydrological modelling in basins

2018 ◽  
Vol 49 (5) ◽  
pp. 1379-1395 ◽  
Author(s):  
Aizhong Ye ◽  
Zheng Zhou ◽  
Jinjun You ◽  
Feng Ma ◽  
Qingyun Duan
Keyword(s):  
Hydrological Model ◽  
Yellow River ◽  
Temporal Distribution ◽  
Yellow River Basin ◽  
Roughness Coefficient ◽  
Hydrological Models ◽  
Distributed Hydrological Model ◽  
The Yellow River Basin ◽  
Improved Model ◽  
New Formula

Abstract Manning's roughness coefficient (n) has a significant impact on routing in hydrological models. However, computational methods for dynamic roughness coefficients are of little concern in current research. Few studies have produced spatial-temporal distributions of the roughness coefficients in basins. In this study, a formula to calculate the n value was established based on a statistical analysis of estimated n values by Manning's formula. The routing model of a distributed hydrological model was then improved using the new formula to calculate n. The roughness coefficient is not a constant; instead, it changes dynamically with changes in water depth and vegetation in the improved hydrological model. The improved model was applied to the Yellow River basin. The results show that using dynamic n can improve the streamflow simulation of hydrological models, especially on slopes. The dynamic spatial-temporal distribution of n can now be used in other models.

Optimization of measurement campaigns for calibration of a conceptual sewer model

2009 ◽  
Vol 59 (8) ◽  
pp. 1523-1530 ◽  
Author(s):  
M. Kleidorfer ◽  
M. Möderl ◽  
S. Fach ◽  
W. Rauch
Keyword(s):  
Hydrological Model ◽  
Stochastic Modelling ◽  
Distributed Hydrological Model ◽  
Volume Number ◽  
Combined Sewer ◽  
Complete Failure ◽  
Long Term Observation ◽  
Event Based ◽  
Measurement Campaigns ◽  
Selection Of

To simulate hydrological models of combined sewer systems an accurate calibration is indispensable. In addition to all sources of uncertainties in data collection due to the measurement methods itself, it is a key question which data has to be collected to calibrate a hydrological model, how long measurement campaigns should last and where that data has to be collected in a spatial distributed system as it is neither possible nor sensible to measure the complete system characteristics. In this paper we address this question by means of stochastic modelling. Using Monte Carlo Simulation different calibration strategies (selection of measurement sites, selection of rainfall-events) and different calibration parameters (overflow volume, number of overflows) are tested, in order to evaluate the influence on predicting the total overflow volume of the entire system. This methodology is applied in a case study with the aim to calculate the combined sewer overflow (CSO) efficiency. It can be shown that a distributed hydrological model can be calibrated sufficiently when calibration is done on 30% of all existing CSOs based on long-term observation. Event based calibration is limited possible to a limited extend when calibration events are selected carefully as wrong selection of calibration events can result in a complete failure of the calibration exercise.

Integrated FAHP-VIKOR model for green supplier selection in a Nickle coating SME

2020 ◽  
pp. 133-139
Author(s):  
Sanatan Ratna ◽  
B Kumar
Keyword(s):  
Staff Training ◽  
Supplier Selection ◽  
Fuzzy Ahp ◽  
Research Work ◽  
Supplier Evaluation ◽  
Green Supplier Selection ◽  
The Past ◽  
Coating Industry ◽  
Sustainability Issue ◽  
Selection Of

In the past few decades, there has been lot of focus on the issue of sustainability. This has occurred due to the growing concerns related to climate change and the growing awareness about environmental concerns. Also, the competition at global level has led to the search for the most sustainable route in the industries. The current research work deals with the selection of green supplier in a Nickle coating industry based on certain weighted green attributes. For this purpose, a hybrid tool comprising of Fuzzy AHP (Fuzzy Analytical Hierarchy) and VIKOR (VlseKriterijumska Optimizacija I Kompromisno Resenje) is used. The Fuzzy AHP is used for assigning proper weights to the selected criteria for supplier evaluation, while VIKOR is used for final supplier selection based on the weighted criteria. The three criterions for green supplier selection are, Ecological packaging, Corporate socio-environmental responsibility and Staff Training. The outcome of the integrated model may serve as a steppingstone to other SMEs in different sectors for selecting the most suitable supplier for addressing the sustainability issue.

Is Hydraulics Over-Used or Under-Used in Storm Drainage?

1994 ◽  
Vol 29 (1-2) ◽  
pp. 53-61
Author(s):  
Ben Chie Yen
Keyword(s):  
Unsteady Flow ◽  
Computational Time ◽  
Time Step ◽  
Flow Routing ◽  
Kinematic Wave Equation ◽  
Storm Drainage ◽  
Saint Venant Equations ◽  
Unsteady Flow Routing ◽  
Selection Of

Urban drainage models utilize hydraulics of different levels. Developing or selecting a model appropriate to a particular project is not an easy task. Not knowing the hydraulic principles and numerical techniques used in an existing model, users often misuse and abuse the model. Hydraulically, the use of the Saint-Venant equations is not always necessary. In many cases the kinematic wave equation is inadequate because of the backwater effect, whereas in designing sewers, often Manning's formula is adequate. The flow travel time provides a guide in selecting the computational time step At, which in turn, together with flow unsteadiness, helps in the selection of steady or unsteady flow routing. Often the noninertia model is the appropriate model for unsteady flow routing, whereas delivery curves are very useful for stepwise steady nonuniform flow routing and for determination of channel capacity.

scholarly journals Dynamics of Single Droplet Splashing on Liquid Film by Coupling FVM with VOF

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 841
Author(s):  
Yuzhen Jin ◽  
Huang Zhou ◽  
Linhang Zhu ◽  
Zeqing Li
Keyword(s):  
Liquid Film ◽  
Weber Number ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Single Droplet ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
The Relationship

A three-dimensional numerical study of a single droplet splashing vertically on a liquid film is presented. The numerical method is based on the finite volume method (FVM) of Navier–Stokes equations coupled with the volume of fluid (VOF) method, and the adaptive local mesh refinement technology is adopted. It enables the liquid–gas interface to be tracked more accurately, and to be less computationally expensive. The relationship between the diameter of the free rim, the height of the crown with different numbers of collision Weber, and the thickness of the liquid film is explored. The results indicate that the crown height increases as the Weber number increases, and the diameter of the crown rim is inversely proportional to the collision Weber number. It can also be concluded that the dimensionless height of the crown decreases with the increase in the thickness of the dimensionless liquid film, which has little effect on the diameter of the crown rim during its growth.

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