M. Tamer Ayvaz

M. Tamer Ayvaz
Pamukkale University · Department of Civil Engineering

Professor

About

60
Publications
11,987
Reads
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1,166
Citations
Additional affiliations
June 2011 - present
Pamukkale University
Position
  • Professor (Associate)
March 2009 - June 2011
Pamukkale University
Position
  • Professor (Assistant)
Education
September 2004 - May 2008
Pamukkale University
Field of study
  • Civil Engineering - Hydraulics
February 2002 - June 2004
Anadolu University
Field of study
  • Civil Engineering - Geotechnics
September 1997 - June 2001
Eskisehir Osmangazi University
Field of study
  • Civil Engineering

Publications

Publications (60)
Article
In this study, a solution approach which is based on the differential evolution (DE) optimization method is developed for optimum design of the sewer systems. In the developed approach, the slope of each pipe is used as the decision variable of the optimization model and the diameters are selected from the available diameters in market for minimizi...
Article
Aquifer parameter estimation is an important problem in groundwater engineering. In practice, these parameters are determined by using the curve matching approaches. However, graphical and/or human-based errors can be made during parameter estimation by using these approaches. To overcome these problems, an optimization based curve matching approac...
Article
In this study, a new simulation-optimization approach is proposed to solve the multipollutant waste load allocation (WLA) problems in surface water systems. The proposed approach simulates the fate and transport of multiple pollutants utilizing the AQUATOX model. Since AQUATOX is an independent model and its integration into the optimization proces...
Article
The main objective of this study is to propose a linked simulation-optimization approach for solving aquifer parameter estimation problems from pumping test results. In simulation part of the proposed approach, the drawdowns at given monitoring points and times are calculated by considering Theis and Hantush approaches for confined and leaky-confin...
Conference Paper
Full-text available
Su kaynaklarının su kalitesini korumak maksadı ile mevcut su kalitesinin özelliği dikkate almadan noktasal atıksu deşarjlarına teknoloji bazlı deşarj standartlarının verilmesi sonucunda su kaynakları günden güne kirlenmektedir. Ülkemizde, noktasal kaynaklı deşarjları düzenleyen yönetmelik olan Su Kirliliği Kontrolü Yönetmeliği (SKKY) ile deşarj sta...
Conference Paper
Full-text available
Bu çalışma geniş havza alanına ve çok sayıda kirletici kaynağına sahip nehirler için kirletici deşarj verilerinin elde edilmesi sorununa bir çözüm sunmaktadır. Çalışma TÜBİTAK tarafından desteklenen 115Y064 numaralı “Ergene Havzası Su Kalitesi Yönetimi İçin Kirletici Parmak İzine Bağlı Coğrafi Bilgi Sistemi Bazlı Karar Destek Sistemleri Geliştirilm...
Conference Paper
Full-text available
Water quality models are important tools in supporting river basin scale decision-making and exploration of pollutant loading effects on the water quality of the receiving waterbody. Contemporary river basin management studies rely on the intensive use of modeling to evaluate pollutant source control strategies. To ensure that water quality standar...
Conference Paper
Full-text available
Bu çalışmanın amacı, Ergene Nehri’nin Meriç Nehri ile birleştiği noktanın mansabında bulunan E01A012 – Yenigörüce Akım Gözlem İstasyonu’nun alanı 10508 m2 olan su toplama havzasındaki yağış-akış ilişkisinin A.B.D. Ordu Mühendisleri Birliği (U.S. Army Corps of Engineers) tarafından geliştirilmiş olan HEC-HMS yazılımı kullanılarak belirlenmesidir. Bu...
Conference Paper
Full-text available
Özet Bu çalışmanın amacı, matematiksel modellerin nehir suyu kalitesi izleme çalışmaları kapsamında üretilen saha gözlemleri ile kirletici ölçüm sonuçlarının değerlendirilmesindeki kullanılabilirliğinin araştırılmasıdır. Çalışma TÜBİTAK tarafından desteklenen 115Y064 numaralı “Ergene Havzası Su Kalitesi Yönetimi İçin Kirletici Parmak İzine Bağlı C...
Conference Paper
In this study, a gradient based solution approach is proposed to analyze the water distribution networks. In the proposed approach, the nonlinear system of equations which are formed by the energy and continuity equations are numerically solved by using a solution approach which is based on the Levenberg-Marquardt optimization method. The main obje...
Conference Paper
The main objective of this study is to propose a linked simulation-optimization approach to determine the parameters of the confined and leaky-confined aquifers from the results of the pumping tests. In the simulation part of the proposed approach, the drawdowns at the given monitoring points and times are calculated by considering Theis and Hantus...
Conference Paper
Flood routing problem is one of the important problems in water resources engineering. There are two widely used flood routing approaches in the literature: hydraulic and hydrological methods. Accuracy of hydrological methods are may be poor compare to hydraulic methods but the application of hydrological methods are easier than hydraulic methods....
Article
Full-text available
Management of groundwater requires a sufficient coverage of accurate groundwater quality data. These data are usually collected from monitoring wells which are spatially distributed in the river basin or the groundwater body that is studied. A minimum number of monitoring wells with an optimum spatial distribution is desired to ensure a cost-effect...
Poster
Full-text available
River hydraulic models are useful tools in watershed management. They are critical components of flood planning studies, and are prerequisites for pollution transport modeling. One of the critical parameters in modeling river hydraulics is the river channel slope. When the river system of a large watershed is of concern, the land surface elevation...
Conference Paper
This study aims to propose a new systematic partitioning approach for Muskingum flood routing models. In the proposed approach, the inflow hydrograph of the flood event is partitioned into sub-regions with different model parameters. The optimum parameter values for each sub-region is determined by using the Generalized Reduced Gradient (GRG) based...
Conference Paper
Identification of the hydrogeological parameters of the aquifer systems is an important problem in groundwater engineering. Generally, these parameters are determined by means of the graphical based curve matching approaches. Although these approaches provide effective results in terms of the calculated aquifer parameters, accuracy of them is mostl...
Article
Full-text available
A hybrid simulation-optimization approach is developed in this study for optimally designing the booster chlorination systems in water distribution networks. In the developed approach, chlorine residuals in the demand locations are determined by using the response matrix (RM) approach. The generated RM is then integrated to an optimization model wh...
Article
In this study, a new partitioning approach is proposed for nonlinear Muskingum flood routing models with lateral flow contribution. The proposed approach is used to partition the inflow hydrograph into different sub-regions so that each sub-region can have its own model parameters. The main advantage of the proposed approach is its independence fro...
Article
In this study, a linked simulation–optimization approach is proposed for optimal dewatering system design for an excavation site. In the simulation part of the proposed approach, an analytical groundwater flow model is used to simulate the flow process in the subsurface. This model is then integrated with two different optimization models where dif...
Conference Paper
Full-text available
Planning and management of groundwater systems require appropriate monitoring data for groundwater quality and aquifer hydraulic head measurements. These data are usually collected from monitoring wells which are spatially distributed in the basin. Since monitoring of groundwater systems can be a time consuming and costly task, a minimum number of...
Article
Summary In this study, a new simulation–optimization approach is proposed for solving the areal groundwater pollution source identification problems which is an ill-posed inverse problem. In the simulation part of the proposed approach, groundwater flow and pollution transport processes are simulated by modeling the given aquifer system on MODFLOW...
Conference Paper
Full-text available
An integrated groundwater management model is developed to determine groundwater supply wells that meet any water demand by considering groundwater vulnerability. The developed model solves the problem by using MODFLOW in the simulation stage and the differential-evolution algorithm in the optimization stage. The groundwater management problem is s...
Article
Disinfection of water in distribution networks is usually achieved by chlorine injection at outlet of the treatment plants. However, such disinfection applications cause non-uniform chlorine residuals since chlorine decays during its propagation in the network. To maintain chlorine residuals within allowable limits, additional chlorine injection lo...
Article
A fuzzy decision-making framework (DMF) is combined with a hybrid genetic algorithm-linear programming (GA-LP) optimization approach to determine the best booster station network for a water distribution system. The proposed hybrid GA-LP model simultaneously optimizes two conflicting objectives; namely, minimization of total chlorine injection dosa...
Article
Full-text available
The objective of this study is to present an optimization approach to determine locations of new groundwater production wells, where groundwater is relatively less susceptible to groundwater contamination (i.e. more likely to obtain clean groundwater), the pumping rate is maximum or the cost of well installation and operation is minimum for a presc...
Chapter
Full-text available
Mathematical simulation models are essential tools to analyze and manage groundwater systems. These models are based on analytical or numerical solutions of partial differential equations (PDEs), which represent groundwater flow for any given set of initial and boundary conditions. Analytical solutions are possible only for simplified cases where t...
Article
A linked simulation-optimization model is proposed for simultaneously estimating the Manning's surface roughness parameters and their associated parameter structures for one-dimensional shallow water flows. In the simulation part of the model, hydrodynamic flow process is simulated by modeling the given flow reach on HEC-RAS. The association of unk...
Article
Full-text available
The quantification of groundwater recharge is an important but challenging task in groundwater flow modeling because recharge varies spatially and temporally. The goal of this study is to present an innovative methodology to estimate groundwater recharge rates and zone structures for regional groundwater flow models. Here, the unknown recharge fiel...
Article
This study proposes a linked simulation-optimization model to solve the groundwater pumping cost minimization problem for existing and new wells to satisfy any given water demand. The proposed model integrates MODFLOW-2000 with HS-Solver which is a recently proposed global-local hybrid optimization algorithm that integrates heuristic harmony search...
Conference Paper
Full-text available
This study proposes a linked simulation-optimization model for solving the groundwater pumping cost minimization problem for satisfying any given water demand. The proposed model integrates MODFLOW-2000, a modular three-dimensional finite difference groundwater flow model, with the heuristic harmony search (HS) optimization algorithm. HS is a recentl...
Conference Paper
Full-text available
The aim of this study is to present a linked simulation–optimisation model to estimate the groundwater recharge rates, their associated zone structures, and hydraulic conductivity values for regional, steady-state groundwater flow models. For the zone structure estimation problem the fuzzy c-means clustering (FCM) method was used. The association o...
Article
This study deals with a new hybrid global–local optimization algorithm named PSOLVER that combines particle swarm optimization (PSO) and a spreadsheet “Solver” to solve continuous optimization problems. In the hybrid PSOLVER algorithm, PSO and Solver are used as the global and local optimizers, respectively. Thus, PSO and Solver work mutually by fe...
Article
This study proposes a linked simulation-optimization model for solving the unknown groundwater pollution source identification problems. In the proposed model, MODFLOW and MT3DMS packages are used to simulate the flow and transport processes in the groundwater system. These models are then integrated with an optimization model which is based on the...
Chapter
Groundwater is not only an important component of water resources, but also a reliable source of fresh water for domestic and industrial uses. However, due to climate change and the fast population growth, the quality and quantity of groundwater resources have been continuously decreasing. Therefore, sustainable management strategies should be deve...
Article
In this article, a hybrid global–local optimization algorithm is proposed to solve continuous engineering optimization problems. In the proposed algorithm, the harmony search (HS) algorithm is used as a global-search method and hybridized with a spreadsheet ‘Solver’ to improve the results of the HS algorithm. With this purpose, the hybrid HS–Solver...
Article
This study proposes a groundwater resources management model in which the solution is performed through a combined simulation-optimization model. A modular three-dimensional finite difference groundwater flow model, MODFLOW is used as the simulation model. This model is then combined with a Harmony Search (HS) optimization algorithm which is based...
Chapter
Mathematical simulation models are widely used to predict the future response of groundwater systems for different flow and mass transport conditions. These models are based on the solution of governing partial differential equations which require some spatially distributed hydro-geological model parameters. However, these parameters are usually un...
Chapter
Full-text available
This study reviews recent applications of the music-inspired HS algorithm, such as music composition, Sudoku puzzle solving, structural design, ecological conservation, aquifer
Article
Full-text available
An artificial neural network (ANN) model is proposed for the simultaneous determination of transmissivity and storativity distributions of a heterogeneous aquifer system. ANNs may be useful tools for parameter identification problems due to their ability to solve complex nonlinear problems. As an extension of previous study - Karahan H, Ayvaz MT (2...
Article
In this study, a simulation/optimization (S/O) model is proposed for the identification of unknown groundwater well locations and pumping rates for two-dimensional aquifer systems. The proposed S/O model uses a finite-difference solution of governing groundwater flow equation as simulation model. This model is then combined with a genetic algorithm...
Article
Full-text available
Abstract: In this study, a solution algorithm that solves Intensity-Duration-Frequency relationship by using Genetic Algorithm (GA) optimization technique has been applied to four city centers in the GAP region. Modified coefficient of efficiency (E) is selected as an objective function and maximization of E is intended. Regional parameters of any...
Article
This study proposes an inverse solution algorithm through which both the aquifer parameters and the zone structure of these parameters can be determined based on a given set of observations on piezometric heads. In the zone structure identification problem fuzzy c-means (FCM) clustering method is used. The association of the zone structure with the...
Article
Abstract: In this study, we propose an inverse solution algorithm through which both the aquifer parameters and the zone structure of these parameters can be determined based on a given set of observations on piezometric heads. In the zone structure identification problem, kernel-based fuzzy c-means (KFCM) clustering method is used. The association...
Article
In this study a spreadsheet application of three-dimensional seepage modeling with an unknown free surface has been carried out. The governing equation is derived using finite differences method in the general case of anisotropic and non-uniform material properties and variable grid spacing. The derived finite difference equation is also modified b...
Article
Abstract A genetic algorithm rainfall intensity (GARI) model has been developed and used to predict the intensities for given return period. It is a one-step solution procedure that may not require any mathematical transformation. The problem formulation is given and the genetic algorithm solution of the problem is presented. The results show that...
Article
Full-text available
ABSTRACT This study proposes an artificial neural network (ANN) model to solve an inverse parameter identification problem for groundwater modeling. It is a problem for which the transmissivities can be obtained for given hydraulic heads. ANN may be a useful tool for parameter estimation problems because of its ability to model complex nonlinear...
Article
Time-dependent groundwater modeling using spreadsheet simulation (TGMSS) model is developed as solution technique. It is a practical method that uses spreadsheets instead of the conventional solution methods. All of the aquifer parameters can easily be described in TGMSS model. The results of TGMSS are validated with MODFLOW. Results showed that TG...
Article
This study proposes a transient groundwater modeling using spreadsheet simulation (TGMSS) model for solving groundwater problems. TGMSS may be considered as a practical method and introduction to groundwater modeling that uses spreadsheets instead of conventional groundwater model codes. Irregular aquifer geometry, variable boundary conditions and...
Article
A new solution method called the dual reciprocity finite differences method (DRFDM) is proposed. The method combines the finite differences method and optimization technique, and can be implemented in a spreadsheet to solve groundwater parameter estimation problems. In the DRFDM model, the hydraulic heads and transmissivities in the solution domain...
Article
ABSTRACT In this paper, a new finite-difference-solution technique for solving transient seepage problems with an unknown free surface has been proposed. The governing finite-difference equations were derived using flux conservation in the general case of anisotropic and nonuniform permeabilities and variable grid spacing, and these equations wer...

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Projects

Projects (3)
Archived project
Investigate methods to eliminate redundancy in groundwater monitoring networks.
Archived project
According to the Water Pollution Control Regulation, technology-based discharge limits are defined for each industry and applied to water bodies without considering the physical characteristics and current water quality of the water body. The main objective of this project is to develop a methodology to determine discharge limits that are based on the status of the receiving water body. These limits will be essentially obtained using a water quality modeling approach that is linked with sophisticated optimization.