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A new realm in spatial planning defies administrative boundaries and adopts larger territories than cities, which encompasses city clusters where cities can both compete and cooperate rather than compete as individual entities. In that regard, various approaches to the delineation of functional regions and "mega" regions have been proposed in time, based on population and employment, the urban landscape, or the interactions between regions in terms of intracity travel or migration flows. This paper proposes a methodology to delineate functional regions as well as megaregions based on the pattern of intercity freight flows and a composite economic indicator, exemplified by a case study of Turkey. A four-step delineation method is proposed in which population and trips are used initially to rank the cities and their hinterlands. Second, hierarchical clustering is carried out to delineate new clusters based on flows, and the resulting clusters are used to delineate functional regions for regional planning purposes. Third, a composite economic indicator (income and wealth index, IWI) is employed to refine and finalize the boundaries, thus ensuring the functional zones' homogeneity as economic clusters. In the last step, megaregions are pinpointed based on the cities of the functional regions using two criteria: IWI (≥0.4089) and GDP (TRY ≥18.3 million) in 2015. The defined regions represent a new geographical scale in regional planning that can aid the central government in addressing leading regional issues: for example, prioritizing governmental investments that are subsidized by national funds aimed at the alleviation of regional inequalities. A future study may focus on the effect of regional economic inequalities on internal migration flows. [ABSTRACT FROM AUTHOR]

This paper aims to define trends and dominant modes in annual instantaneous maximum flows (AIMF) covering the period 1961–2014 from 10 gauge stations located in different river basins in Turkey. To achieve this aim, discrete wavelet transform (DWT) and additive wavelet transform (AWT) in conjunction with the Mann-Kendall (MK) test are used and compared for the first time. Moreover, global wavelet spectrum (GWS) is employed to test the significance of the most effective periodic components. The sequential MK test is also used to determine the start or change points of trend in AIMF series. From the MK trend results, five stations showed a statistically significant (at a 5% level) negative trend for AIMF series and short-term periodic components (2 and 4 years) were found to be the most effective components, which are responsible for producing a real trend founded on the data series. The GWS analysis indicated that the most dominant components identified are significant. In addition, the MK- z values of the most effective periods derived from AWT generally showed a better agreement with MK- z value of original time series with higher correlation coefficient compared to those of DWT. The sequential MK graphs of the AWT-based time series also produced a better harmony with the sequential MK of the original data. Finally, the results showed AWT coupled with the MK provided a very efficient and accurate analysis for defining the most effective modes in the AIMF series and can be successfully used in any hydrological time series. [ABSTRACT FROM AUTHOR]

This paper presents a study of liquefaction-induced lateral ground displacements along the coast of Izmit Bay during the 1999 Kocaeli (Izmit)-Turkey earthquake. The paper discusses: (1) observed ground displacements after the earthquake, (2) the results of field investigations by means of borings and in situ index tests, including standard penetration tests, static cone penetration tests, and piezocone tests, (3) analyses of expected lateral displacements using two empirical models and one semiempirical model, and (4) comparisons between observed and calculated lateral ground movements. The three models provide inconsistent predictions of observed lateral ground displacements, with one method overpredicting and two methods both overpredicting and underpredicting observed lateral ground displacements by large amounts. Thus, it appears that there is a need for improved engineering tools for prediction of small to moderately significant lateral ground displacements (lateral displacements of approximately 0.1-2.5 m) at soil sites with similar ground characteristics to the case history sites presented herein. [ABSTRACT FROM AUTHOR]

During the past several decades, many studies illustrated the importance of socioeconomic factors on interregional migration in different countries. Interregional migration has had an immense impact on Turkey's population dynamics after the 1950s. This study aims at investigating the patterns of interregional migration in Turkey during the period of 2008 to 2010 using a hierarchical cluster analysis. First, the paper gives background information about interregional migration by providing the ratios of immigration and emigration with respect to the population and the characteristics of the regions between 2007 and 2010. Second, interregional immigration and emigration flows are investigated by the use of a hierarchical clustering analysis with different linkage techniques, e.g., single, complete, average, and others, which determine how the distance between two clusters should be defined to represent actual partitioning. Then, the best partitioning of the regions is selected based on a popular internal or unsupervised criterion, called cophenetic correlation. According to the results obtained by the single linkage that yielded the highest cophenetic correlation, the country's largest city, Istanbul, dominates the largest cluster of the country consisting of the regions from east to west both immigration and emigration flows. These analyses have shed light on the complex relationship of the interregional migration in Turkey. Regional inequalities can be overcome first by understanding this complex relationship of the interregional migration in the country. Then, under a national strategic development plan, public investments can be directed more to, and private investments can be encouraged in, underdeveloped regions via the tool of economic subsidies in order to create economic sustainability across the regions throughout the country. [ABSTRACT FROM AUTHOR]

Lean construction is the term that corresponds to the reflection of the production system developed at the Toyota Corporation (automotive industry) on the construction industry. Turkish contractors constitute a large portion of the local economy and are important global actors in contracting business. Lean construction-based research and practice, as a production management-based approach for increasing the effectiveness and efficiency of the construction industry, are scarce among Turkish contractors. This paper presents the results of a questionnaire prepared to predict the lean conformance levels of Turkish contractors and discusses the results. The comparative strengths and weaknesses of Turkish contractors for a lean construction initiative are highlighted. The findings that are presented in this paper can be used as a starting point to disseminate the research and practice in lean construction among Turkish contractors in the future. A similar kind of research can be repeated to compare the lean conformance levels in different countries and to evaluate the lean construction programs at different companies after the introduction of lean construction. [ABSTRACT FROM AUTHOR]

Construction delays are common in construction industry and create major concerns for project performance. Construction delays are caused by many factors. The aim of this paper is to identify delay factors on construction projects and analyze these factors with the relative importance index method. For this purpose, 83 different delay factors were identified, categorized into nine major groups, and visualized by the Ishikawa (fishbone) diagram through detailed literature review and interviews with experts from the construction industry. The relative importances of these delay factors were quantified by the relative importance index method. The ranking of the factors and groups were demonstrated according to their importance level on delay. According to the case study results, the factors and groups contributing the most to delays (those needing attention) were discussed, and some recommendations were made to minimize and control delays in construction projects. [ABSTRACT FROM AUTHOR]

Following the 1999 Marmara earthquakes, urban regeneration has gained particular importance in redevelopment of housing areas particularly in historical districts of Istanbul. Local governments, upon new roles and responsibilities regarding postdisaster conditions as well as the changing global trends, called for innovative planning approaches which involve the community. In this respect, some questions are raised in the planning agenda: While performing the new roles, what kind of institutional changes should local governments experience? How should local community be involved in this process? The paper considers the conditions of spatial and community change in realizing urban regeneration as a collaborative action through the case study of Matra—Regeneration of Istanbul Metropolitan Area (Matra REGIMA) project which highlights the fundamental capacity building requirement for both local government practitioners and the community in order to achieve the necessary actions. Consequently, this study highlights the strengths and limitations of the capacity building program applied in Zeytinburnu toward implications for future collaborative actions within urban regeneration schemes. [ABSTRACT FROM AUTHOR]

The heuristic method is one of the methods used for the scheduling of resource-constrained projects. This method is commonly used in programming the projects with high number of activities and resources such as construction investments. This paper investigates the effectiveness of three heuristic method priority rules applied in the resource scheduling of ten Turkish housing estate projects which were scheduled according to three preselected priority rules [maximum remaining path length (MRPL), latest finish time (LFT), and minimum slack time (MNSLCK)] in resource-constrained conditions. The performance of each priority rule was evaluated in relation to the duration of the project. The results revealed that MRPL priority reduced the project duration to minimum in six projects, whereas LFT priority yielded the best duration results in three projects and MNSLCK priority in only one project. [ABSTRACT FROM AUTHOR]

This paper conducts a catchment-scale analysis of extreme rainfall events of the reference (1961-1990) and three future climate periods (2013-2039, 2040-2070, and 2071-2100) for Rize Province, Turkey. The extreme value theory (EVT) is applied to analyze observational and projected extreme rainfall data including regional climate model (RCM) outputs guided by two general circulation models (GCM) under SRES-A2 and RCP8.5 greenhouse gas scenarios. A new rapid and effective bias correction method is also developed and applied to adjust the climate models simulations. The EVT analysis results demonstrated significant differences between the model runs for both the reference and future periods with considerable spatial variability in rainfall extremes. Based upon the assembled mean results, approximately a 30% decrease in the median value of extreme rainfall events is projected over the study region for the near future, 2013-2039, and middle of the century. This change dramatically decreases to 15% of its historic value at the end of the century. The results from the implemented GCM-RCM combinations revealed that more intense rainfalls are produced by the combination forced by the RCP8.5 scenario. In addition, the results from goodness-of-fit tests among different distribution models showed that general extreme value distribution can be used appropriately to characterize the behavior of projected extreme rainfalls over the study region. [ABSTRACT FROM AUTHOR]

In the last 30 years, there have been various findings related to the effects of construction investments––especially housing investments––on the economic development of urban areas. However, the impact of public housing investments on economic development in rapidly and dynamically developing countries with high housing demand has not been sufficiently discussed. This article presents an examination of the impact of housing production as a public housing investment on the economic development of provinces at the macro level through the case of Turkey. In the study, we analyzed the impact of public housing investments on the economic development of the provinces in Turkey between 2004 and 2018. Since 2004, Turkey has pursued a policy of increasing public housing investments, and for this purpose, the structure of the Toplu Konut İdaresi Başkanlığı (TOKI––the Mass Housing Authority), which is a strong and autonomous centralized public institution, has changed. Despite the increase in public housing investment at the country level as a result of this policy, the effect of public housing investment on economic growth at the provincial level has not been determined. In this study, panel data analysis methods were applied, regression analyses were conducted, and the findings were evaluated. The findings of the analyses showed that, although housing investments (private sector) have had an impact on the development of the provinces at the macro level, public housing investment and production have not played a decisive role in the economic development of the provinces. [ABSTRACT FROM AUTHOR]

This study argues that businesses, as principal units of both the economy and the urban environment, show different performances in the postdisaster period that in turn affect the community-level recovery. To this end, the paper examines the long-term recovery process of businesses through empirical research in Adapazari, Turkey, which was greatly challenged by the 1999 earthquake. A total of 232 respondent firms there were selected through stratified random sampling. Data were gathered via questionnaire designed to identify the factors that determined their success during the recovery process. It is hypothesized that the recovery performance of businesses is affected by a number of factors that are categorized thus: internal factors, response capacity, and the extent of damage within the business recovery model. The findings of the study indicate that business recovery is associated positively with operating in the finance, insurance, and real estate (FIRE) sector, but negatively correlated with operating in the trade and service sectors, and with variables expressing the states of being financially in trouble and taking more damage. A policy frame is provided for the integration of business recovery into community recovery by focusing on the predictors of business vulnerability and loss. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to determine the radiological hazard level of various commercial scrap piles in Turkey. Samples were taken from metal scrap yards near the city of Istanbul, Turkey. In this study, radioactivity measurements were carried out on these samples. The activities of , , , and were determined in the laboratory by gamma-ray spectrometry. The highest , , , and activities were found to be 8,735, 465, 524, and , respectively, in residues of technologically enhanced, naturally occurring radioactive material (TENORM) scraps. Radiation doses due to gamma exposure and radon emanation from residues were determined. Site-specific test results were determined to be less than the exemption limits for external radiation. According to these results, external radiation doses were less than for workers. The main factors due to radon inhalation were based on measured effective radium content, mass, and areal exhalation rates as well as the radon emanation power. [ABSTRACT FROM AUTHOR]

This paper investigates the multicenter development course of Istanbul based upon urban travel patterns in the city. The spatial distribution of population and employment between 1970 and 2000 illustrated a decentralizing trend in the urban structure. Hierarchical clustering analysis was used to determine relatively homogenous groups of interactions and to explain the interaction patterns among the districts. The results of the study supported the multicenter development at the lower level on both continents (Asia and Europe), and at the upper level between the continents. Determination of efficient locations of new subcenters was suggested for further research. [ABSTRACT FROM AUTHOR]

This paper presents a study that aims to define the present position of Turkish construction companies in terms of strategic management. It is based on a survey measuring strengths and weaknesses in the “strategic management” practices of Turkish construction companies, and thus reveals potential opportunities and threats in a generalized manner. The results highlight the current strategic management practice of construction firms for designing their own future. Toward this aim, a detailed questionnaire was administered to 52 construction companies. The culture of companies and their perceptions of strategic management were shown to have serious shortcomings. However, specialization on different project types through joint venture companies established by their partners was found to be a major strength of many companies. These companies also pointed out the developing and unstable nature of both the political and economic structure of Turkey as their most significant threat. This disadvantage has inclined many firms to choose investment in the private sector as a response. [ABSTRACT FROM AUTHOR]

Most of the public school buildings in Turkey and Peru are built according to a small number of template plans. Over the years, these template plans are kept the same while the structural designs are varied with the seismic design codes in force. During recent strong earthquakes in Turkey and Peru, the design concepts and construction styles for these template school buildings have been put to test. In this paper, observed earthquake performances of template reinforced concrete school buildings with moment-frames or moment-frames and shear walls are compared. The comparison reveals choices in design that were successful as well as those that were not. The disastrous results of “captive columns” are demonstrated in illustrations from what has been observed in recent earthquakes in these seismically active countries. It is shown that since 1997 the Peruvian practice has been producing school buildings that perform well during strong earthquakes. [ABSTRACT FROM AUTHOR]

In this paper, a gravity model is used to capture urban influences in a single variable that combined urban population and distance to urban centers. The model was developed under the theory that urbanization pressures increase as population increases and distances from the urban center decrease. The data were gathered by the questionnaires of investment areas of several natural gas pipeline projects in eight different cities of Turkey. The results suggest that both land rents and urban influences have been important factors affecting the farmland prices. [ABSTRACT FROM AUTHOR]

Turkey has a large economy and, thus, it expects a very large growth in energy demand. Today, Turkey’s economy is mainly dependent on oil, natural gas, and electricity. On the other hand, Turkey’s energy production meets nearly 35% of its total primary energy consumption. Turkey is an energy importing country. Turkey presently has considerable renewable energy sources. The most important renewable sources are hydropower, wind, solar, geothermal, and biomass. Turkey has about 1% of the total world hydroelectric potential and its significant potential for geothermal power production is ranked seventh in the world. This paper presents the energy situation and potential of the renewable energy sources in Turkey. [ABSTRACT FROM AUTHOR]

Provision of adequate electricity is one of the major factors for industrial and commercial development. However, decisions on the expansion of electricity are bogged down by high investment requirements and nonsynchronized expansion between electricity generation and transmission systems. As a rule, the investment requirements for these types of projects are immediate but their benefits can be obtained only in the long-term basis albeit electricity planners base their decisions on immediate requirements of shorter terms. As investment funds are very hard to come by, the funds, if available, should be utilized to maximum by minimizing the investment through a synchronized expansion planning of both electricity generation and transmission systems. This paper attempts to address this opportunity. We have proposed here a mixed integer model to develop concurrent transmission and generation investments plans. The model selects new generation plants or generation capacity expansions for existing plants that are located on the interconnected network by considering explicitly congestion in the transmission network. Hence the model contributes to this area by filling in the gap between models for developing long-term power generation policies and power flow models focusing on transmission network expansion. The application of the model in Turkey’s electricity network highlights the country’s congested areas in the transmission network, which might lead to loss of load and inefficient generation capacity expansion if not tackled properly. The analysis shows that a cost efficient generation expansion is possible to realize in congested regions if proper transmission expansion decisions are made concurrently with generation expansion decisions. [ABSTRACT FROM AUTHOR]

This paper explores the impact of some key infrastructure measures in transportation, telecommunication, and electricity production sectors on labor productivity, using data on two-digit sectors for the Turkish economy for the years 1987-2006. We find both statistical and economic significance for the positive productivity impact of infrastructure on productivity growth, for road, port, and air transport, telecommunications, and electricity production. In the railway sector, only measures of actual freight carried are consistently and significantly associated with productivity growth, whereas other measures of infrastructure are insignificantly or inversely associated with productivity growth. Given that the railway-transport sector is the only infrastructure sector that remains closed to competition and private participation, this raises the issue of the significance of private sector involvement in infrastructure provision. [ABSTRACT FROM AUTHOR]

The quality of a project depends on the performance of the design team; design faults can be prevented by effective team management. In this context, effective leadership is needed to enable effective team management. The preference for more than one style of leadership is inevitable in complex business life because different styles are contingent on different situated contexts. This paper focuses on determining which of the two leadership styles architects predominantly prefer in Turkey, and whether there are any differences in the preferences of leadership styles between the design and production phases in a construction context. Data were collected through a questionnaire on leadership styles, which was distributed to 40 architects from different design offices in Turkey. The leadership styles are gathered into two primary groups: transactional and transformational leadership styles. Two styles fall under transactional leadership-coercive and authoritative-and four styles fall under transformational leadership-affiliative, democratic, coaching, and pacesetting. The results show that Turkish architects prefer affiliative, authoritative, and pacesetting leadership styles, but when two styles need to be combined, their choices are the affiliative-democratic and affiliative-coaching leadership styles. Within the frame of this research, the leadership preferences of leading Turkish architects are discussed in light of Hofstede's parameters on Turkish national culture. Within this context, compatibility with the national culture of the leaders' preferences for these behaviors may affect the overall performance of architectural design teams. [ABSTRACT FROM AUTHOR]

A conceptual framework has been developed to investigate value innovations within construction companies. A visual metaphor has been defined to model the innovation system where the elements of the model are objectives, strategies, environmental barriers/drivers, and organizational factors. The major idea is that none of the elements of the model alone can explain the innovative capability, and elements as well as their interrelations should be considered concurrently to investigate how the innovation system works in construction companies. An application of the framework has been demonstrated by 11 cases taken from the Turkish construction industry. General findings of the research have been reported as well as specific company examples that demonstrate the major mechanisms of the innovation system. The research findings have revealed that environmental factors can have both hindering and supporting impacts on the innovation system, depending on other elements of the framework. The type of innovations is strongly related to company targets, strategies, strengths/weaknesses, and environmental factors. Moreover, matching of appropriate strategies with organizational properties leads to an increase in innovative capacity. [ABSTRACT FROM AUTHOR]

This study utilizes remotely sensed pre- and post-disaster images in order to detect any change specifically associated with structural and major regional damage caused by natural disasters such as a strong earthquake. Currently, postdisaster reconnaissance is conducted using mostly ground-truth teams. Although by using this method high-resolution assessment can be provided, it is very time consuming, costly and sometimes not practical. This study investigates an unsupervised near near-time method of reconnaissance using a pair of coregistered remotely sensed images of the same scene acquired at different times as input. The output is an image (mostly binary) in which “changed” pixels are separated from “not-changed” ones. The approach is fully deterministic using principal component analysis, normalization and further setting a threshold to classify pixels. For verification, a set of multispectral images from Golcuk-Turkey 1999 earthquake was used. It is concluded the program generates very similar results as obtained by ground-truth teams. [ABSTRACT FROM AUTHOR]

Because delays are common in construction projects, causes of delays are widely investigated in the construction-management literature. However, there is no consensus on the relative severity of various causes of delay because severity may change with respect to project characteristics, such as the type of project and/or procurement type. Public–private partnership (PPP) has been utilized extensively in recent years, and the number of public construction works worldwide that adopted the PPP has increased gradually. However, the delay causes specific to PPPs have not been investigated deeply. Moreover, the perceptions of different stakeholders on causes of delay in PPP projects have never been investigated, although the perception difference between stakeholders is considered an important issue in delay management. In this study, the perceptions of three key stakeholders—namely, consultants, the private sector, and the public sector—on delay causes in build–operate–transfer (BOT) projects performed in Turkey, which is one of the leading countries in terms of number of PPP projects and the total value of PPP projects, were investigated. The delay causes specific to BOT projects were evaluated by conducting a workshop to determine the causes of delay in the Turkish market. The identified delay causes were evaluated using the analytical hierarchical process (AHP) by 11 participants who represent consultants, the private sector, and the public sector. The correlations between the respondents were evaluated using Pearson's correlation coefficient and Spearman's rank correlation coefficient. This study showed that the most important delay causes are related to the uncertainties and changes. In particular, private sector participants emphasized the importance of certainty on political and governmental issues and minimization of changes in design to avoid delays in BOT projects. In contrast, the respondents from the public sector proposed that a detailed feasibility study and preliminary plan should be prepared and the transfer stage should be planned carefully. Finally, different perceptions were observed among the stakeholders at the stages where the collaboration of the stakeholders is limited. [ABSTRACT FROM AUTHOR]

Design alternatives in construction projects are compared with concurrently taking various criteria into consideration, such as costs, functionality, and constructability. This case study introduces a comparison process based on lifecycle costing (LCC) between two design alternatives in an irrigation project, the Seyhan River Yedigöze İmamo?glu Irrigation Project, being implemented in the southern region of Turkey. Decisions related to irrigation projects in Turkey are important because of their effect on the agricultural development and because of the high amounts allocated from the national budget for their implementation. In this regard, comparing the design alternatives properly during the design development stage is critical to exploring the superior design. The aim of this case study is to show how considering only the facility initial construction costs, while ignoring LCC, may lead to wrong decisions, through the example case of an irrigation project undertaken in Turkey. Comparison of two different design alternatives has revealed that Design Alternative 2 (pipe network and concrete covered open main channel of 15.812 km) is superior to Design Alternative 1 (pipe network and concrete covered open main channel of 57.562 km) from the perspective of LCC and such technical criteria as constructability, operation easiness, and water saving. [ABSTRACT FROM AUTHOR]

On October 23, 2011, a destructive earthquake of occurred in Eastern Turkey. The event occurred on a previously unknown fault with a thrust mechanism and resulted in 604 deaths and major structural damage to the buildings. The highways at the Van earthquake zone were open to service of rescue operations, aid trucks, and regular traffic immediately after the devastating event. As a success story, the bridges closer to the fault line than the towns of Van and Erciş were observed to have minimal damage, such as minor support movements and cracks at the shear keys. Among the 14 highway bridges in the region evaluated by the authors, only two adjacent bridges, Bendimahi-II, had minor structural cracking along the column height. As expected, the bridges of concern were observed to perform in the essentially elastic state. The main focus of this study was to evaluate the seismic bridge design practice in Turkey, which resulted in a successful seismic performance of the earthquake-zone bridges. As an illustrative example, Bendimahi-II bridge, the closest one to the fault line, was studied through an analytical investigation. [ABSTRACT FROM AUTHOR]

Protecting and improving water resources play an important role for meeting the future demand for drinking water and preventing flood events. Increasing population tends to cause a shift from rural to urban areas, which results in the alteration of concentration time, water quantity, and flow rate. Because of these changes, specific solutions need to be investigated to prevent flood and overflow. For this purpose, calibrated hydrodynamic models should be developed to understand the hydrodynamic behavior of the catchment. Sazlıdere Watershed, which provides an average of of water per year, is one of the most important watersheds of Istanbul, Turkey. There is a tremendous population increase in the area, and moderate flood events are frequently observed. Therefore, in this study, a calibrated hydrodynamic model for Sazlıdere Watershed was developed by using the Environmental Protection Agency Storm Water Management Model (EPA SWMM). The model is calibrated by using the rainfall and flow data obtained from the stations we set in the area. The most sensitive parameters of the hydrodynamic model are determined to be Manning's roughness coefficient for both channels and subcatchments followed by the infiltration parameters, i.e., hydraulic conductivity and the initial soil-moisture condition. The flow developed on the watershed was simulated both under typical rainfall events and under extreme cases, namely, high urbanization and storm events with a high return period. It is observed that even under typical storms, floods developed on the watershed; and finally, several flood control options are suggested. [ABSTRACT FROM AUTHOR]

The purpose of this study is to apply the method of artificial neural networks (ANNs) to predict the hourly solar radiation of six selected provinces in Turkey. Six neurons-receiving input signals of latitude, longitude, altitude, day of the year, hour of the day, and mean hourly atmospheric air temperature-were used in the input layer of the network. One neuron producing a corresponding output signal of hourly solar radiation was utilized in the output layer of the network. Two different models have been analyzed in the ANNs for training and testing. The results obtained from both models were compared by using different neurons, mean squared error (MSE), coefficient of determination (), and mean absolute error (MAE). According to the results, the MSE value of training data in Model II was better than Model I. [ABSTRACT FROM AUTHOR]

Recently, Turkey has been hit by several moderate to large earthquakes that resulted in significant loss of life and property. The 1998 Adana and 1999 Marmara earthquakes caused severe damage not only in residential buildings but also in industrial buildings. Most of the industrial buildings in Turkey are constructed as prefabricated structures. Prefabricated structures are preferred because of their economic and rapid production. In the present study, the earthquake behavior and infill wall effects for single story hinged industrial prefabricated buildings were investigated. Nonlinear pushover, performance-based, time history, and fragility analyses were carried out for a sample prefabricated industrial building. Infill wall effect was investigated by adopting a diagonal strut model. The structural behavior and load-deformation relationship of prefabricated industrial buildings both with and without infilled walls were evaluated and compared. Results of the study show that masonry infill walls can affect the lateral load-carrying capacity and modify the earthquake response of prefabricated industrial buildings. [ABSTRACT FROM AUTHOR]

In this study, a comparison of the economic viability of wind turbine and diesel water pumping systems (WPSs) is presented for five different sites located in the north central Anatolia region of Turkey. A water pumping system was considered for water usage. The wind energy potential was investigated by using the time-series wind data taken from the Turkish State Meteorological Service (TSMS). Data were processed using FORTRAN computer code. The wind power and the amount of water to be pumped was evaluated using various wind energy conversion systems (WECSs), and unit energy and water cost were measured using life the cycle cost (LCC) method for these WECSs. Moreover, the cost of water to be delivered utilizing WPS with diesel generator (DG) was compared with the cost of water delivered viaWPS with WECS. Sinop had reasonable wind potential to produce electrical energy using WECS and the minimum cost of energy output and cost of water to be delivered were $0.24/kWh and $3.70/m3 in this observation station, respectively. In addition, if the water demand is lower than 1,000 m3 in Sinop, such as the water consumption of a household and farm, the WPS with WECS (for Turbines 1, 2, and 4) will be more plausible than the WPS with DG system. If a medium-scale WECS were set up in Sinop, it could supply both the annual electrical demand and water consumption of a household and farm. Finally, Sinop is going to be a marginal area for cost-effective electrical energy generation as the costs of WECSs are lowered. [ABSTRACT FROM AUTHOR]

Historical structures are one of the most precious pieces of cultural accumulation. In this study, an interdisciplinary work was conducted to assess the structural condition of a historical masonry structure, Urla Kamanlı Mosque in İzmir, Turkey. The structure is a member of group of structures, Yahşi Bey Complex, which includes a Turkish bath, a tomb, two fountains, and a primary school. The structure dates back to early 14th century to mid-15th century. History investigation, measurement survey, long-term settlement, and moisture observations were conducted. Nondestructive and destructive material tests were performed on stone, brick, and mortar. 3D finite-element model of the structure was used to investigate the critical locations of the structure under its self-weight, seismic load, and settlement load. Linear elastic and nonlinear settlement analyses were conducted to investigate the reason for massive cracks challenging the structural integrity. [ABSTRACT FROM AUTHOR]

The determination of built-in material properties is a difficult step during the structural assessment of historical structures. Large variations of material characteristics and the difficulty of obtaining an adequate number and type of material samples are among the major problems. In this study, the material characterization of the approximately 135 years old historical Akaretler Row Houses was carried out. Since several structural walls of the row house complex were to be removed according to the restoration design, a large number of different types of specimens could be collected for laboratory tests and a considerable amount of in situ destructive and nondestructive tests was carried out. The laboratory tests included mechanical, physical, and chemical tests on original materials such as bricks, mortar, brick prisms, cores consisting of two layers of bricks and one layer of mortar between bricks, and wallets. The in situ tests included destructive shear tests and nondestructive rebound hammer tests. At the end of the extensive experimental study, the basic material characteristics of the late period Ottoman construction system were obtained. In addition relations between various mechanical characteristics of the construction materials, as well as the relations between the results of the laboratory and in situ tests, and destructive and nondestructive tests are presented. [ABSTRACT FROM AUTHOR]

In the 1990s, Turkey started a fast transfer program in which a large proportion of government-managed irrigation systems were put into the hands of Water Users’ Associations (WUAs) in a very short space of time. One of the first systems to be handed over was the Gediz Basin. This study aims to set out the effects of the transfer of irrigation management in this basin on water and land productivity and water supply. For this purpose, the indicators of productivity and water supply proposed by the International Water Management Institute have been used to show changes between the pretransfer, transfer, and post-transfer periods. WUA averages for the post-transfer period calculated from the results ranged $2,076–$2,898 ha-1 for output per command area, $2,747–$4,585 ha-1 for output per irrigated area, $0.26–$0.68 m-3 for output per irrigation supply, $0.30–$0.63 m-3 for output per unit water consumed, 0.88–1.49 for relative water supply, and 0.99–1.99 for relative irrigation supply. During the period evaluated by the study, there was a decline in water supply indicators, as against a steady increase in the productivity of water and land use. The basic reason for this decrease in supply is the long-lasting and ongoing drought in the region. [ABSTRACT FROM AUTHOR]

The first hardfill dam in Turkey, Cindere Dam, has recently been constructed and a number of instruments have been installed. The aim of this study is to review the capability of the current instrumentation system and to observe the feasibility of possible alternative measurement systems. To this end, the current instrumentation system has been evaluated as a whole with reference to the parameters measured, instruments, and data acquisition system. Afterward, an alternative instrumentation system was developed by considering additional parameters and instruments to the current system. Furthermore, each instrumentation system equipped with manual and automatic data acquisition systems was considered. The comparison between the current and alternative instrumentation systems was also carried out in terms of technical and economical aspects. Although the current instrumentation system was found to be satisfactory according to the commonly used dam instrumentation practices, it was observed that the alternative system promotes the current one in various aspects without increasing the cost significantly. [ABSTRACT FROM AUTHOR]

This study presents investigations regarding visual inspection, dynamic testing, and finite-element modeling of an approximately 80-year old reinforced concrete tied-arch railway bridge that is still in service in Turkey. Investigations were conducted as part of a systematic periodic inspection along Ankara-Zonguldak railway line. The bridge is subject to heavy freight trains with increasing axle loads. Field tests such as material tests and dynamic tests were used to calibrate the finite-element model of the bridge. Detailed information regarding testing and model updating procedure is given. Based on test results, computer model was refined. The calibrated model of the bridge structure was then used for structural assessment and evaluation. Despite sufficient overall safety, local details were found to be problematic. Due to insufficient bond length in hanger-to-arch connection, a strengthening scheme using steel channel sections was proposed. [ABSTRACT FROM AUTHOR]

Prediction of suspended sediment load (SSL) is important for water resources quantity and quality studies. The SSL of a stream is generally determined by direct measurement of the suspended sediment concentration or by employing sediment rating curve method. Although direct measurement is the most reliable method, it is very expensive, time consuming, and, in many instances, problematic for inaccessible sections, especially during floods. On the other hand, measuring precipitation and flow discharge is relatively easier and hence, there are more rain and flow gauging stations than SSL gauging stations in Turkey. Furthermore, due to its cost, measurements of SSL are carried out in longer periods compared to precipitation and flow measurements. Although daily precipitation and flow measurements are available for most of the Turkish river basins, at best semimonthly measurements are available for SSL. As such, it is essential to predict SSL from precipitation and flow data and to fill the gap for the missing data records. This study employed artificial intelligence methods of artificial neural networks (ANN) and neurofuzzy inference system, the sediment rating curve method, multilinear regression, and multinonlinear regression methods for this purpose. The comparative analysis of the results showed that the artificial intelligence methods have superiority over the other methods for predicting semimonthly suspended sediment loads. The ANN using conjugate gradient optimization method showed the best performance among the proposed models. It also satisfactorily generated daily SSL data for the missing period record of Gediz River, Turkey. [ABSTRACT FROM AUTHOR]

The main goal of this study was to determine regional probability distributions for the annual maximum flood data observed at 45 streamflow gauging sites in the Kucuk and Buyuk River Basins in Turkey using index flood L moments. Mann–Kendall trend analysis was previously applied to the streamflow gauging sites’s observed data, and dam effects were sought at all stations. Seven sites were omitted from the analysis because they were not unregulated or trends were present in the data. A regional analysis was performed on the remaining 36 sites, which satisfied the screening criteria of having a minimum record length of 10 years, representing unregulated natural flows, and passing the Mann–Kendall test at the 5% significance level. Data from the 36 streamflow gauging sites in the basins were screened using the discordancy measure (Di). Homogeneity of the region was then tested using the L-moments heterogeneity measure by carrying out 500 simulations using the four parameter kappa distribution. Based on these tests, the streamflow gauging sites were found to constitute two homogeneous subregions, namely the upper- and lower-Menderes subregions. Seven comparative regional flood frequency analysis studies were carried out for each subregion using various L-moment-based frequency distributions: the generalized logistic, general extreme value, generalized normal, Pearson Type III, generalized Pareto, kappa, and the five-parameter Wakeby. Based on the L-moment goodness of fit statistic criterion, the generalized normal extreme value distribution has been identified as the best-fit distribution for the upper- and lower-Menderes subregions. A Monte Carlo simulation was used to evaluate the results on the basis of the relative root mean square error relative bias. For estimation of floods of various return periods for ungauged catchments, a regional relationship between mean annual peak flood and catchment area was developed and coupled with the regional flood frequency relationship derived for gauged catchments. [ABSTRACT FROM AUTHOR]

Droughts are complex events which may impair social, economic, agricultural, and other activities of a society. The present hydroclimatological study comprises three stages. First, a Markov chain model based on annual flows at a gauging station located on the Göksu River (Turkey) is utilized. Second, a critical drought analysis is conducted. Third, the influences of the North Atlantic Oscillation (NAO) on the probability distribution functions (PDFs) of critical droughts have been documented. Drought duration is used as a key parameter in the Markov chain model. As the model degree should be defined prior to applying a Markov chain model to a series of observations, a model degree of first order has been selected according to the results of the Akaike information criteria and Bayesian information criteria. The exact PDFs of the critical drought duration in a finite sample that follows the first-order Markov chain have been determined by the enumeration technique. The critical drought duration is the possible maximum duration likely to occur over the economic life of any water resources system. The expectations of the critical drought duration are provided for different transitional probabilities. The influences of NAO on the PDFs of critical droughts have been examined for two opposite cases; namely, the period of negative NAO index values (1936–1971) and the period of positive NAO index values (1972–2000). The results of this analysis clearly indicate that NAO series have quantifiable influences on the transition probabilities and expectation of the critical drought duration. As a result, the probability distribution functions obtained for various critical drought durations in the observations of the Göksu River may be implemented as a robust tool to determine a design value with the concept of risk. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop an optimum flow prediction method, based on the adaptive neural-based fuzzy inference system (ANFIS) and artificial neural network (ANN). Each methodology was applied to river flow predicting in Manavgat Stream in the southern part of Turkey. In application, Manavgat Stream flows were predicted from Dalaman Stream, Alara Stream, and Göksu Stream flows. Each stream is located in different catchments. For monthly streamflow predictions, data were taken from the General Directorate of Electrical Power Resources Survey and Development Administration. Used data covered a 35-year period (1969–2003) for monthly streamflows. The ANFIS and ANN models had only one output with three input variables. Comparison of the ANFIS and ANN models showed a better agreement between the ANFIS model estimations and measurements of monthly flows than ANN. With the help of the ANFIS model for interbasin flow prediction, it was possible to estimate missing or unmeasured data. [ABSTRACT FROM AUTHOR]

The Bosphorus Tube Tunnel beneath the Bosphorus Strait is under construction in Istanbul, Turkey, using the tunnel-element immersed method. It is well known that the Bosphorus Strait has a two-layer current system with a rapidly changing flow. To maintain quality and safety of tunnel-element installation, it is important to accurately forecast the current-flow condition for periods of 48 h to identify windows of opportunity for the element-immersion process. In this study, a forecast system is developed based on the information collected and analyzed over an immediate past five-day period (120 h) to provide a two-day (48 h) period current prediction required for the element-immersion process. The system consists of a water-level forecast model and a current forecast model. The water level is forecasted from air pressure and wind information obtained from on-line monitoring data and meteorological service forecasts. The current is then forecasted from the water-level data taking the two-layer density interface effect and the immediate preceding 120-h current data (including its concurrent value) into consideration. This selected data-analysis period is determined based on our operational experience at the site. Both models are statistically constructed and calibrated using a year-long observation data set (October 2004–September 2005). It is found that the proposed forecast system gives sufficiently accurate current information for safe ongoing marine construction operation. [ABSTRACT FROM AUTHOR]

In this study, wind energy density in the southern and southwestern region of Turkey was investigated by using the Weibull and Rayleigh probability density functions, and the wind atlas analysis and application program (WAsP). Hourly wind speeds and directions collected by the General Directorate of Electrical Power Resources Survey Administration were used. Before the construction of the wind turbine generator in these locations, several fundamental properties of the site such as wind behavior, availability, continuity, and probability should be carried out in order to provide the necessary information to the potential investors about cost and economical aspects of planning the wind energy project. The dominant wind direction, probability distribution, Weibull parameters, mean wind speed and power potential of all stations were determined by the Weibull and Rayleigh models, and the WAsP program. The results obtained with these models were compared with the measured data. Finally, it is found that these regions have a reasonable wind power potential and they are suitable for planting wind energy turbines. However, Belen is the most promising and convenient site for production of electricity from wind power. [ABSTRACT FROM AUTHOR]

The purpose of this study is to develop an integrating evaporation estimation model using a data mining process for the Lakes District in the southern part of Turkey. Lakes Eğirdir, Kovada, and Karacaören Dam are located in the Lakes District. The proposed data mining process is applied on these lakes for evaporation estimation. The daily pan evaporation data used in the data mining process are taken from State Hydraulic Works in southern Turkey. These data cover an 8-year period between 1998 and 2005 inclusively for daily pan evaporation of Lakes Eğirdir, Kovada, and Karacaören Dam. It is known that a developed integrated daily pan evaporation model is necessary for these lakes, which are so important to the Lakes District. Therefore, a data mining model having two inputs and one output is developed. Input parameters used in the developed models for Lakes Eğirdir, Kovada, and Karacaören Dam were daily pan evaporation values of Lakes Kovada + Karacaören Dam, Lakes Eğirdir + Karacaören Dam, and Lakes Eğirdir Kovada, respectively. As a result, in comparing the developed models with measured daily pan evaporation values, the REP tree model has better agreement with measured daily pan evaporation than other models. The results show the developed model was more accurate. [ABSTRACT FROM AUTHOR]

The aim of this study is to survey and evaluate permanent housing structures built after the Marmara earthquakes based on the principles of earthquake resistant design of reinforced concrete structures. The seismicity of Turkey requires immediate attention as there is a high probability of another major earthquake event in the next 30 years in Istanbul. The classification of structural systems, the damage patterns and behaviors of structural systems, and structural and nonstructural components under lateral earthquake loads, are analyzed. Based on this analysis, reliable structures can be built without overextending the Turkish economy, and loss of life and structural damage can be reduced by designing structures with greater earthquake energy dissipation capacity. The selection of project areas and the strength of the structural system are thoroughly analyzed taking postearthquake public psychology into account. Structural characteristics of permanent housing built subsequent to the Marmara earthquakes are critiqued and documented with a case study. [ABSTRACT FROM AUTHOR]

Hydrologic regionalization can be employed for importing data from gauged sites to ungauged sites. A number of techniques have been developed for hydrologic regionalization. This study presents an approach that combines three regionalization techniques in order to obtain homogeneous regions and compute streamflow at desired ungauged sites. First, an agglomerative hierarchical clustering algorithm is used to determine the number of homogeneous regions. Second, homogeneous regions are defined by the k-means partitioning method. Third, the flow duration curve (FDC) method is used to compute streamflow discharge at desired ungauged sites in homogeneous regions. The combined approach was then applied to 26 river basins in Turkey having 1,410 river gauging stations, where homogeneous regions were identified and streamflow discharge was calculated at ungauged sites. At many of the unguaged sites, small hydropower projects are being planned for development. It was found that these 1,410 river gauging stations (26 river basins) can be grouped into six homogeneous regions. Homogeneous regions were found to be better distributed in the nonhierarchical k-means method than in the hierarchical method. FDCs, constructed for each homogeneous region, fit monthly discharge data with correlation coefficients between 95 and 100% for 85.7% of the gauging stations, between 85 and 94% for 12.5% of the stations, and between 72 and 84% for 1.8% of the stations. [ABSTRACT FROM AUTHOR]

Induced travel demand is a critical phenomenon for developing countries because neither road network nor the vehicle ownership have reached their contended phases. This leads to the opinion that induced demand is valid for developing countries or increase in travel demand is only a result of rapidly rising vehicle numbers and other socioeconomic parameters. In this study, induced demand estimation methodology is modified from the point of view of a developing country by introducing the application of tendency comparison of lane mile elasticities under different lag terms for control and highway investment data. Beside vehicle miles traveled, travel per vehicle (TPV) and number of vehicles for long-term effects are tried as new demand indicators. The selection of socioeconomic variables is also considered more expediently because of their rapid and wide changes in developing countries. The travel data of Turkish state highways are used for application. TPV is found to be the most distinguishable criterion of induced travel demand for Turkey with 2.0 times relative increase for private TPV and 3.5 times for commercial TPV. Demand elasticities based on commercial travel are found to be more permanent than the private travel based ones. Besides, longer peak period, which indicates the maximum difference in elasticity of control and test data, is obtained as 5 years for commercial travel which is 3 years for private purposed travel in lag consideration based on road supply conditions. [ABSTRACT FROM AUTHOR]

This work assesses the state of maintenance of the concrete-lined trapezoidal canals of the Menemen irrigation system at the end of the Lower Gediz Basin according to the values of roughness (n) and active canal capacity (ACC). The study was carried out on two main canals, five secondary canals, and 12 tertiary canals at 45 measurement points. Average values of n and ACC were found to be 0.023 and 69%, respectively, for the main canals, 0.018 and 93%, respectively, for the secondary canals, and 0.023 and 81%, respectively, for the tertiary canals. The fact that values of n for the selected canals were higher than projected values and higher than the limit values, which would indicate adequate maintenance, and that the related ACC values were low, indicates that maintenance is insufficient in these canals. In order for maintenance work to be carried out more effectively, it may be suggested that new techniques should be applied for canal linings, which are economical and longer lasting, that farmers who benefit from the system should be given a more active role in maintenance work, and most importantly, that the associations responsible for maintenance should be supported financially in these activities. [ABSTRACT FROM AUTHOR]

Although many traffic circles have been designed in Turkey, in recent years few studies have been made on the capacity and performance of roundabouts. In practice, two major problems at intersections need to be solved: traffic accidents and limited intersection capacity. With this in mind, the applicability of various capacity models for single-lane roundabouts to six selected roundabouts in Izmir, Turkey, is discussed. The results show that the HCM2000 procedure can be used as an effective tool for an initial prediction of single-lane roundabout capacity if the lower and upper boundary limits are calibrated. But, since the research was conducted with limited data, the accuracy of the results should be tested with more data sets. Further studies should be conducted to develop a more reliable capacity and performance analysis procedure, especially for Turkey. [ABSTRACT FROM AUTHOR]

This study is aimed to utilize of the Golden Horn (GH) sediments in briquette production after they were conveyed to a stone quarry in Istanbul, Turkey. Two different types of mixtures were prepared for hydrothermal agglomeration. In the first type, GH sediment and lime and in the second type GH sediment, lime, and quartz were mixed. For thermal agglomeration, GH sediment was used alone. First, physical, chemical, and mineralogical properties of the GH sediments were determined. Then, the prepared briquette samples were agglomerated under 0.5, 1.0, and 1.5 MPa water vapor pressure for 4 h with the hydrothermal method in the autoclave and then under 1,273 °K constant temperature for 2 h in a thermal agglomeration oven. Density change of the briquettes as a result of agglomeration compressive strength were measured and the results of the mechanical data and x-ray analysis of sediments subjected to thermal and hydrothermal treatment are presented. Calcium silicate hydrate peaks were observed only at 1.0 MPa between 423 and 473 K in the first type of mixture and the highest compressive strength value (27 MPa) was observed in briquettes prepared without quartz in the hydrothermal method at 1.5 MPa. This study showed that it is possible to produce briquettes from GH sediments and this will reduce environmental pollution. [ABSTRACT FROM AUTHOR]

Alibey Dam is located near Istanbul in Turkey on the Alibey Stream, 4.5 km north of its point of confluence with Golden Horn, an ancient submerged river mouth. It was constructed as an earthfill dam over 30-m-thick soft valley sediments. Before the construction of the dam, field and laboratory tests were performed to determine the geotechnical characteristics of the foundation soils. During the construction and many years after the construction of the earthfill embankments, including the cofferdams and the intermediate fills, the response of the foundation soils was monitored by extensive field instrumentation generating a unique long-term (over 25 years) database. With proper instrumentation and careful monitoring of the collected data, field construction rates could be adjusted and the earth dam was safely constructed on the thick soft deposits. Approaches to settlement prediction were evaluated in a historical context, starting with the simplified one-dimensional approach available at the time of construction to more sophisticated analyses including the employment of modern numerical methods, in terms of the recorded data. Standard subsurface exploration and field testing supplemented with conventional laboratory testing provided the relevant material parameters that were used in the finite element method. The only exception to this was the overall hydraulic conductivity of the deposit, which controlled the rate of consolidation. Early field observations were used to assign the appropriate hydraulic conductivity. An elastoplastic soil model in a coupled analysis of consolidation was employed in the analysis that yielded realistic predictions of field behavior in response to the complex construction history. The accurate prediction and monitoring of the behavior of soft and thick soil layers subjected to staged construction, as in the case of Alibey Dam, is very important for planning of the construction as well as the expected behavior after construction. [ABSTRACT FROM AUTHOR]

With increasing awareness of gains and importance of the strategic use of information and communication technologies (ICTs), the implementation rate of ICTs in the construction sector is increasing. However, these technologies have not been covered by legal and contractual practices. The industry needs to implement application frameworks and legal restructuring of the existing related laws and regulations to use ICT in a legal and contractually valid environment. The EU-funded eLEGAL project, which defined a legal framework for ICT uptake in construction, is selected as a model project to address legal and contractual issues regarding ICT use in the Turkish construction industry. The applicability of this project’s results are discussed by using real cases and defining the barriers, opportunities, methods, and tools to use ICT in a legally admissible manner in the Turkish construction industry. [ABSTRACT FROM AUTHOR]

In this study, an evaluation has been made of the realization level of the planned targets in irrigation planning for all of the 13 water user associations (WUAs) of the Gediz Basin. This evaluation was made according to six performance indicators: level of realization of irrigation ratios, level of realization of crop pattern, dependability, adequacy, efficiency, and equity for the years 1999–2002. Seven associations were successful in irrigation ratio realization, and four were successful in crop pattern. Failure of other WUAs can be reduced by collecting farmers’ declarations and evaluating them with greater care and sensitivity. Water delivery in the general irrigation plan was found to be poor with regard to dependability and equity, and good with regard to the indicators of adequacy (except in the year 2001) and efficiency. In order to improve dependability, the period when water is diverted from the source and the period when water is needed must coincide completely. In order to improve equity, delivery of water to WUAs must be carried out taking account of water requirements predicted in the general irrigation plan. When these two indicators are improved, adequacy and efficiency will improve also. [ABSTRACT FROM AUTHOR]