Papers by Cevza Melek Kazezyilmaz Alhan
Environmental Engineering and Management Journal
Pamukkale University Journal of Engineering Sciences, 2017
Su kaynaklarının ekonomik, sosyal ve çevresel açıdan en verimli şekilde kullanılması, canlı hayat... more Su kaynaklarının ekonomik, sosyal ve çevresel açıdan en verimli şekilde kullanılması, canlı hayatın sürdürülebilmesi için kaçınılmazdır. Özellikle kentleşme ile birlikte betonlaşma ve buna paralel olarak topraktaki geçirimsiz yüzey artmakta, toprakta meydana gelen sızma azalmakta ve yağış sonucu yüzeyde toplanan fazla su hızlı bir şekilde akışa geçerek taşkına neden olmaktadır. Kentleşme ile beraber toprağa sızamayan su, doğal arıtım olan topraktan mahrum kalmakta ve yüzeyde biriken kirliliği doğrudan su kaynaklarına taşımaktadır. Bu durum su kalitesini olumsuz yönde etkilemekte ve su kirliliğine neden olmaktadır. Bu çerçevede, çevresel sürdürülebilirliğin sağlanması, su kaynaklarının korunması ve kentleşmenin çevre ve su kaynakları üzerindeki olumsuz etkilerinin azaltılması için yeni hidrolojik yöntemlere ihtiyaç duyulmaktadır. Bu çalışma kapsamında, kentleşme sonucu arazi kullanımında meydana gelen değişimler ile artan yüzeysel akış ve su kirliliğini önlemek için Düşük Etkili Kentleşme (DEK) tipi En İyi Yönetim Uygulamaları (EİYU) incelenmiştir. Yüksek yüzeysel akış ve yayılı kirlilik kaynaklarının olumsuz etkilerini azaltmak için kullanılan bir yağmur suyu yönetimi uygulaması ve DEK çeşidi olan "biyotutma" araştırılmıştır. Bu amaçla kurulmuş olan bir deney düzeneği ile biyotutmanın hidrolojik verimliliği ve performansı gözlemlenmiştir. Yapılan deney sonuçları değerlendirilerek biyotutmanın pik debinin azalması üzerine etkisi incelenmiştir. Biyotutma kolonlarında kullanılan malzemelerin mekanik özellikleri incelenmiştir. Elde edilen sonuçlar değerlendirildiğinde malzeme tipi ve özelliklerinin biyotutma kolonlarında suyun tutulmasında etkili olduğu görülmüştür. Kum içeriğinin fazla olması ile kolonlardaki çıkış debisinin arttığı ve ince taneli malzemelerin artması ile azaldığı gözlemlenmiştir. Efficient use of water is vital for economic, social and environmental sustainability of water resources. Especially, urbanization and thus high imperviousness results in a decrease in infiltration and percolation. Consequently, surface runoff generated over the surface increases tremendously and results in floods. Surface runoff also washes off the pollutants that are built up on the surface during dry days which results in poor water quality. Therefore, new methods in hydrology are necessary for environmental sustainability, protection of water resources, and mitigation of impacts of urbanization on environment and water resources. In this study, Low Impact Development (LID) Best Management Practices (BMP) are investigated in order to prevent high surface runoff and water pollution due to land use change caused by urbanization. Bioretention, which is a LID type of storm water management practice, is investigated to mitigate impacts of high surface runoff and nonpoint source pollution. For this purpose, an experimental setup is developed to observe the hydrologic efficiency and performance of bioretention. Performance of bioretention on peak flow decrease is observed by evaluating experimental results. The mechanical properties of materials used in bioretention columns are investigated. It is observed that the material type and properties are effective in retaining water in bioretention. As the sand content increases, the outflow at the exit of the column also increases and if the fine grained material increases, the outflow at the exit of the column decreases.
The crucial role of surface water/ground water interactions in water resources and hydrologic app... more The crucial role of surface water/ground water interactions in water resources and hydrologic applications has been taking center stage recently. The interaction of ground water occurs with all types of surface waters (e.g., streams, lakes, wetlands and reservoirs) and pollutants in either surface or ground water get mixed and the quality of both sources is affected by each other. Wetlands are land areas which are frequently transitional between uplands and flooded systems. In the last two decades, the beneficial aspects of treatment wetlands have been studied. Yet, investigating surface/ground water interactions within wetlands has only recently become a critical issue, especially in order to understand the effect of wetland hydrology on water quality. For this purpose, a comprehensive wetland model is being developed that incorporates these surface/ground water interactions. The effect of wetlands on storm water runoff is investigated by routing the overland flow through the wetla...
The crucial role of surface/ground water interactions in determining contaminant concentration di... more The crucial role of surface/ground water interactions in determining contaminant concentration distributions both in streams and ground water has only recently been recognized. In particular, in pool and riffle or meandering types of streams, long tails and small peaks are observed in the stream tracer data, which reflects the influence of surface/subsurface flow on solute concentration. Bencala and Walters (1983) first presented a comprehensive transient storage model for streams to explain the effects of surface storage and the hyporheic zone in stream concentration. We complement these surface/subsurface modeling efforts by incorporating the transient storage zone in a conjunctive stream-aquifer model. The core of this conjunctive model is MODFLOW which computes the ground water flow in the aquifer, while DAFLOW computes unsteady stream flow with diffusion wave routing technique and MOC3D computes the solute transport in ground water. In addition, an explicit finite difference pa...
Human activities affect natural water resources and these effects also cause some problems such a... more Human activities affect natural water resources and these effects also cause some problems such as flood inundation which is a big natural disaster in urban areas for many years. In this study, flood analysis of Çayırova Stream and its basin, located in Kocaeli, Turkey, is carried out by developing a hydrodynamic model for the region. And flood mechanism and inundation behavior of Çayırova watershed are investigated. The lack of culvert through the Çayırova Stream and careless interference with the riverbed resulted in major flood events and significant damage in the watershed. Çayırova stream passes through the Gebze Institute of Technology (GIT) Campus and this place faces with problems due to the narrow cross-sections of the channel and lots of inadequate culverts and bridges along the stream. In this study, the hydrodynamic model of the watershed and the riverbed are developed by using Watershed Modeling System (WMS) and Environmental Protection Agency Storm Water Management Sys...
Hydrology Research, 2014
Ground water should be used efficiently and improved for sustainable water management plans. For ... more Ground water should be used efficiently and improved for sustainable water management plans. For this purpose, comprehensive ground water flow models are developed incorporating surface/ground water interactions. Typically, these models require a significant amount of hydrological parameters and the sensitivities of these parameters on interaction mechanisms need to be clarified. Therefore, in this study, the role of the geometric shape of the stream on stream/ground water interactions is investigated. First, an analytical solution for two-dimensional ground water flow is developed with sloping stream boundary in an isotropic and homogeneous aquifer. Then, ground water head distribution and hyporheic exchange flow between stream and aquifer are obtained by conducting sensitivity analyses with prototype models developed using Visual MODular Finite-Difference FLOW in order to observe individual effects of each stream property. Finally, by incorporating the highest possible stream/grou...
2nd Annual International Conference on Architecture and Civil Engineering (ACE 2014), 2014
La Houille Blanche, 2014
The land development and increase in urbanization in a watershed affect water quantity and water ... more The land development and increase in urbanization in a watershed affect water quantity and water quality. Especially, uncontrolled urbanization causes flood and poor water quality which results in an increase in peak flow rate and in Total Suspended Solid (TSS) concentration. Low Impact Development (LID) is a Best Management Practice (BMP) and land planning method which may be used to manage storm water runoff in order to reduce flooding as well as simultaneously improve water quality. In this study, the impact of "LID-BMP" on surface runoff and TSS is investigated by employing a calibrated hydrodynamic model for Sazlıdere Watershed which is located in Istanbul, Turkey. For this purpose, a calibrated hydrodynamic model was developed by using Environmental Protection Agency Storm Water Management Model (EPA SWMM). For model calibration and validation, a rain gauge and a flow meter are set into the field and rainfall and flow rate data are obtained. And then, several LID types are selected such as retention basins, vegetative swales and permeable pavement and their influence on peak flow rate and pollutant buildup and washoff for TSS are obtained. Consequently, the possible effects of LID on surface runoff and TSS in Sazlıdere Watershed are observed.
Journal of Hydrology, 2006
The behavior of solute transport in pool and riffle, or meandering types of streams, is greatly i... more The behavior of solute transport in pool and riffle, or meandering types of streams, is greatly influenced by surface/subsurface flow and solute transport interactions. It is important to model these processes accurately in rivers and streams to improve downstream water quality. Two decades ago, Bencala and Walters (1983) [Bencala, K.E., Walters, R.A., 1983, Simulation of solute transport in a mountain pool-and-riffle stream-a transient storage model. Water Resources Research 19(3), 718-724] introduced the transient storage model to represent the movement of solute from main streams into stagnant zones and back to the main stream. This model includes the effect of both surface storage, in which water is stationary relative to the main channel and the hyporheic zone, to which water moves from the main channel, flows through and returns to the main channel. However, their simplified approach lumped the surface storage and hyporheic zones together in a single storage zone. In this study, we take a step towards a mechanistic model to explain the physics of water exchange between the surface water and the porous media by developing an improved mathematical model. For this purpose, we include the advection and dispersion processes into the transient storage zone, and we consider the hyporheic zone as a transient porous media from surface water to ground water. We use this improved model to solve a test problem in order to demonstrate its capabilities. Finally, we simulate the Uvas Creek experiment and compare our results to the observations described in Bencala and Walters (1983) [Bencala, K.E., Walters, R.A., 1983, Simulation of solute transport in a mountain pool-and-riffle stream-a transient storage model. Water Resources Research 19(3), 718-724] and to results of the existing transient storage model obtained by using OTIS.
Journal of Hydrology, 2008
The general solutions for contaminant transport in a saturated semi-infinite porous media are der... more The general solutions for contaminant transport in a saturated semi-infinite porous media are derived by using the Laplace transform and Fourier transform, along with their transform inversions, under the conditions of one-dimensional seepage flow and the three-dimensional dispersive effect. The analytical expression of contaminant concentration in a porous medium, subjected to a local contaminant source with arbitrary geometry, and intensity that varies with time and coordinates is derived by the source function method based on the elementary solution of an instantaneous point contaminant source. The results show that an exponentially degenerated contaminant source injected into the porous medium migrates gradually toward the depth and width of the porous medium due to the convective water flow and diffusion induced by molecular and mechanical movement, along with deposition of the contaminant on the solid matrix surface. The contaminant concentration in a porous medium subjected to a cyclic contaminant source exhibits cyclic fluctuations due to the fluctuation of the contaminant source applied on the porous surface; concentrations reach a quasi-steady state, with the same fluctuation phase as the contaminant source. The hydrodynamic dispersion effect accelerates the migration processes of the contaminant in the vertical direction as well as the diffusion in the horizontal direction, resulting in a dramatic rise in the contaminant concentration in a short period of time.
Applied mathematics and …, 2005
The reliability of several finite difference numerical formulations for solving one-dimensional k... more The reliability of several finite difference numerical formulations for solving one-dimensional kinematic and diffusion wave equations that describe overland flow is investigated. Particular emphasis is placed on two numerical schemes which are second order accurate in space ...
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Papers by Cevza Melek Kazezyilmaz Alhan