A study on uncertainty-based flood analysis

Download

MustafaBerkayAKPINAR_MSc_Thesis.pdf

Date

2023-1

Author

Akpınar, Mustafa Berkay

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

198
views

171
downloads

A hydraulic model is a collection of mathematical equations that give a simple representation of reality with the inputs obtained from hydrological assessments to estimate flow, flow depth and velocity in channels. Basically, hydraulic models require digital elevation models, Intensity-Duration-Frequency curves, maximum flows from hydrographs, and roughness coefficients from field studies and/or satellite images. Inherently, these major inputs have uncertainties due to the complex nature of the evaluation processes of inputs and boundary conditions. In recent years, researches have shown that roughness coefficients and evaluated maximum flows may have error margins of 5% to 15%; this may result in underestimation for expected flow depths compared to evaluated ones. In this study, convenient probability distributions in the nature of uncertainties in peak discharge of the input hydrograph and Manning’s roughness value have been investigated separately and in combined manner in flood modelling. The study was conducted and modelled with an automated Monte Carlo-based method of HEC-RAS and Visual Basic Applications software in the catchment of Yılanlı Dere, in Samsun. 1-D hydraulic model was used. The results show that the maximum flows and roughness values may cause uncertainties in flow depths up to 10% of the total capacity of cros-sections without overflow in this region. Moreover, distances of the cross-sections to the hydraulic structures existing along the river and topographic conditions can also directly affect these uncertainties. It is obtained that the distributions of the flow depth at the cross-sections were changed.

Subject Keywords

Hydraulic Models, Uncertainties, Probabilistic Flood Modelling

URI

https://hdl.handle.net/11511/102103

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

A finite element variational multiscale method for the Navier-Stokes equations Volker, John; Kaya Merdan, Songül (Society for Industrial & Applied Mathematics (SIAM), 2005-01-01) This paper presents a variational multiscale method (VMS) for the incompressible Navier-Stokes equations which is defined by a large scale space L-H for the velocity deformation tensor and a turbulent viscosity nu(T). The connection of this method to the standard formulation of a VMS is explained. The conditions on L-H under which the VMS can be implemented easily and efficiently into an existing finite element code for solving the Navier - Stokes equations are studied. Numerical tests with the Smagorinsky ...
A Mechanistic Model for Predicting Frictional Pressure Losses for Newtonian Fluids in Concentric Annulus SORGUN, MEHMET; Ozbayoglu, M. E. (Informa UK Limited, 2010-01-01) A mathematical model is introduced estimating the frictional pressure losses of Newtonian fluids flowing through a concentric annulus. A computer code is developed for the proposed model. Also, extensive experiments with water have been conducted at Middle East Technical University, Petroleum and Natural Gas Engineering Department Flow Loop and recorded pressure drop within the test section for various flow rates. The performance of the proposed model is compared with computational fluid dynamics (CFD) soft...
An analysis of a linearly extrapolated BDF2 subgrid artificial viscosity method for incompressible flows Demir, Medine (Elsevier BV, 2020-10-01) This report extends the mathematical support of a subgrid artificial viscosity (SAV) method to simulate the incompressible Navier-Stokes equations to better performing a linearly extrapolated BDF2 (BDF2LE) time discretization. The method considers the viscous term as a combination of the vorticity and the grad-div stabilization term. SAV method introduces global stabilization by adding a term, then anti-diffuses through the extra mixed variables. We present a detailed analysis of conservation laws, includin...
A study on major seismological and fault-site parameters affecting near-fault directivity ground-motion demands for strike-slip faulting for their possible inclusion in seismic design codes Akkar, Sinan; MOGHIMI, SAED; Arıcı, Yalın (2018-01-01) We investigate the role of major seismological (magnitude, pulse period, fault length, seismic activity, orientation of incident seismic wave with respect to fault-strike) and geometrical (fault-site geometry) parameters to understand the variations in ground-motion demands due to near-fault directivity (NFD) effects. To this end, we used a suite of probabilistic strike-slip earthquake scenarios and established the elastic spectral amplitude distributions conditioned on the above investigated parameters. Th...
Two approximation schemes to the bound states of the Dirac-Hulthen problem IKHDAİR, SAMEER; Sever, Ramazan (IOP Publishing, 2011-09-02) The bound-state (energy spectrum and two-spinor wavefunctions) solutions of the Dirac equation with the Hulthen potential for all angular momenta based on the spin and pseudospin symmetry are obtained. The parametric generalization of the Nikiforov-Uvarov method is used in the calculations. The orbital dependence (spin-orbit-and pseudospin-orbit-dependent coupling too singular 1/r(2)) of the Dirac equation are included to the solution by introducing a more accurate approximation scheme to deal with the cent...

Citation Formats

M. B. Akpınar, “A study on uncertainty-based flood analysis,” M.S. - Master of Science, Middle East Technical University, 2023.