Publications

Prof. Avci has published in the following topics.

  • Groundwater Hydraulics and Contaminant Transport
  • Surface Water Hydraulics
  • Numerical Methods
  • Sustainable Financing for Infrastructure Projects
  • Environmental and Social Impact Assessments 

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Analysis of CO2 Emission Reduction and Energy Interactions in Turkey Via Genetic Algorithm and BUEMS-macro for Electric Vehicles

Conference paper
Cem Tiranlar and Cem Avcı
Publication year: 2019

The electricity demand forecasting of the transport sector in Turkey has been carried out by taking into consideration official estimates, energy infrastructure needs, sector-specific growth and development expectancies. A survey for end user perceptions towards electric vehicles has been conducted, and two alternative ways are employed: (i) top-down approach using genetic algorithms and (ii) bottom-up approach using the Boğaziçi University Energy Modeling System (BUEMS), a technologically detailed linear activity analysis framework. BUEMS is calibrated under various scenarios to evaluate the impact of additional electricity demand on the power generation mix and CO2 emissions.

Environmental and Social Risk Management in Emerging Economies: An Analysis of Turkish Financial Institution Practices

Book Chapter
Isil Gultekin and Cem Avcı
Responsible Investment Banking Risk Management Frameworks, Sustainable Financial Innovation and Softlaw Standards
Publication year: 2015

Abstract

Turkish Financial Institutions (FIs) have come to recently realise that nonfinancial factors can materially affect an institution’s long-term performance. Environmental and social issues (i.e. pollution, resource depletion, wastes, biodiversity, land acquisition and resettlement, labour and working conditions, occupational/community health and safety, cultural heritage) have been recognised to pose risks to the Turkish FIs through their project finance operations. This awareness developed in parallel to the concept of sustainability being embraced by Turkey’s corporate sector. Several large Turkish lending institutions have developed environmental and social (ES) management systems for evaluation of the projects considered for financing. Although the majority of these are based on international standards that include ES performance criteria of the International Finance Corporation (IFC), European Bank for Reconstruction and Development (EBRD) and European Investment Bank (EIB), they do not yet fully encompass the requirements of the international standards in the actual implementation process. The projects considered for financing are typically subject to the Turkish Environmental Impact Assessment (EIA) Regulations that set the commitments for the project owner for environmental protection based on the Turkish regulatory framework. Compared to the international standards, there are gaps in the Turkish EIA studies that include a lack of a structured impact assessment, insufficient baseline studies and limited community engagement programmes. These gaps may eventually pose legal risks to the project during development and operations and also to the lending institution in terms of financial and reputational risks. Although several institutions have developed ES management systems internally, experience shows that these systems initially focus on following the Turkish EIA process without fully assessing issues such as biodiversity, cultural heritage and social impact assessments including expropriation and resettlement issues. This chapter will provide an overview of ES procedures of large lending institutions in Turkey and discuss generic data gaps between Turkish EIA studies and international requirements as well as the evaluations of ES risk management systems in place. Discussions include main risks and opportunities in applying international standards in investment finance in Turkey as well as identifying future trends.

Electricity Demand Projection for Turkey: Bottom-up Modelling Approach and Comparison with EU and Asia

Conference paper
Zafer Ozturk, Gurkan Kumbaroglu, Cem Avci & Merve Kucuk
Energy Security, Technology and Sustainability Challenges Across the Globe 38th IAEE International Conference Antalya, Turkey May 25-27, 2015
Publication year: 2015

The main intention of this study is to develop an electricity demand projection for Turkey for the period 2012-2035.
The project covers the five main clusters of electricity demanding sectors that are: i) industrial sector, ii) residential
sector, iii) Service/commercial sector, iv)transport sector, and v) others. Overall electricity demand forecasting
process till end year 2035 has been carried out by taking into considerations of official demographic projections, and
energy efficiency improvement expectations as well as the sector based growth and development expectancies.

Assessing radial transmissivity variation in heterogeneous aquifers using analytical techniques

Article
Cem B. Avci A. Ufuk Sahin
Hydrogeology Journal Volume28, Issue23 15 November 2014 Pages 5739-5754
Publication year: 2014

Abstract

Pumping tests are one of the most commonly used in situ testing techniques for assessing aquifer hydraulic properties. Numerous researches have been conducted to predict the effects of aquifer heterogeneity on the groundwater levels during pumping tests. The objectives of the present work were as follows: (1) to predict drawdown conditions and to estimate aquifer properties during pumping tests undertaken in radially symmetric heterogeneous aquifers, and (2) to identify a method for assessing the transmissivity field along the radial coordinate in radially symmetric and fully heterogeneous transmissivity fields. The first objective was achieved by expanding an existing analytical drawdown formulation that was valid for a radially symmetric confined aquifer with two concentric zones around the pumping well to an N concentric zone confined aquifer having a constant transmissivity value within each zone. The formulation was evaluated for aquifers with three and four concentric zones to assess the effects of the transmissivity field on the drawdown conditions. The specific conditions under which aquifer properties could be identified using traditional methods of analysis were also evaluated. The second objective was achieved by implementing the inverse solution algorithm (ISA), which was developed for petroleum reservoirs to groundwater aquifer settings. The results showed that the drawdown values are influenced by a volumetric integral of a weighting function and the transmissivity field within the cone of depression. The weighting function migrates in tandem with the expanding cone of depression. The ability of the ISA to predict radially symmetric and log‐normally distributed transmissivity fields was assessed against analytical and numerical benchmarks. The results of this investigation indicated that the ISA method is a viable technique for evaluating the radial transmissivity variations of heterogeneous aquifer settings.

Keywords

  • inverse solution algorithm
  • radial transmissivity variation
  • aquifer heterogeneity

Identification of aquifer and well parameters from step-drawdown tests

Article
Cem B. Avci, Emin Ciftci & A. Ufuk Sahin
Hydrogeology Journal volume 18, pages1591–1601(2010)
Publication year: 2010

A new analysis technique has been proposed for interpreting transient step-drawdown test data. The proposed method is based on taking the derivative of the drawdown with respect to time for the entire pumping test period to eliminate the time-independent well-loss terms. The derivative function is subsequently integrated to obtain the time-dependent aquifer drawdown as a continuous function. The well-loss parameters are then obtained with higher accuracy once the aquifer behavior is identified. The proposed method is applicable for analyzing data obtained not only from ideal confined aquifers but also from other aquifer types (i.e. unconfined) and non-ideal aquifers (i.e. heterogeneous). The technique was tested for synthetically generated and field data; the proposed approach was noted to provide accurate aquifer and well-loss parameter estimates. The results of the proposed method were compared with those of some of the existing methods for analyzing step-drawdown test data and were found to be more reliable and robust.

Assessment of advective–dispersive contaminant transport in heterogeneous aquifers using a meshless method

Journal paper
Emin Ciftci, Cem B. Avci, Osman S. Borekci & A. Ufuk Sahin
Environmental Earth Sciences volume 67, pages2399–2409(2012)
Publication year: 2010

Groundwater solute transport phenomena typically occur in water-bearing zones with heterogeneous solute dispersive characteristics and/or media hydraulic properties. A radial basis function collocation method (RBFCM)-based numerical method was developed in order to investigate the ability of RBFCM to accurately portray solute transport phenomena under heterogeneous conditions. Simulations were performed for 1-D and 2-D transport scenarios in which scale-dependent dispersivity fields were taken into consideration and compared with available analytical solutions. Different radial basis functions (RBFs) were employed for assessing the sensitivity of the present method on the selected RBFs. The simulation results were also compared with the results of MT3DMS which is a modular three-dimensional transport model with alternative solution schemes including the method of characteristics, the implicit central finite difference and the third order total variation diminishing finite volume. The proposed model was also used to simulate a real case condition where solute transport through a two-layer soil medium had been investigated experimentally. The results showed that RBFCM represented a powerful tool for predicting the solute transport occurrence under heterogeneous conditions with high accuracy.

Environmental Impact Assessment Standards and Thresholds for Sanitary Landfills

Book Chapter
Cem Avcı and Erol Guler
Standards and Thresholds for Impact Assessment pp 103-111| Cite as
Publication year: 2008

Abstract

Municipal waste landfills represent a viable and quite commonly used method for domestic waste disposal even though the method has been used for centuries. Municipal waste landfills, at the same time, pose potentially adverse environmental impacts that need to be considered during the site selection process, landfill design, operational and post closure phases. An Environmental Impact Assessment (EIA) study represents an effective tool built into the legislative process of many countries and institutions that can be used to identify potential adverse effects on human health, environment impacts and ecologic risks. The decision makers are able to review all the necessary data on potential impacts prior to project approval. In this manner appropriate remedial measures can be identified and implemented prior to the project start-up.

Keywords

Environmental Impact Assessment Sanitary Landfill Ground Water Quality Landfill Cover Environmental Impact Assessment Process