Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Geogenic Determinants of Indoor Radon Exposure in Izmir (West Türkiye)(Pergamon-Elsevier Science Ltd, 2026) Alkan, Turkan; Simsek, Celalettin; Sac, Murat; Uzelli, Taygun; Taskin, NurcihanRadon, a naturally occurring product of uranium decay, is the second leading cause of lung cancer. I(center dot)zmir Province in western T & uuml;rkiye, situated within the Aegean extensional regime, comprises complex fault-bounded basins that favor indoor radon accumulation. This study evaluates the spatial variability and geogenic controls of indoor radon to delineate radon-prone zones with public-health relevance. Indoor radon was measured in 79 dwellings distributed across major lithologies and structural settings; detectors were deployed in basements to capture soil-gas infiltration. Concentrations ranged from 12 to 366.5 Bq/m3 (mean 118 Bq/m3), exceeding the national average of 81 Bq/m3; 32 % of sites surpassed the EPA action level of 148 Bq/m3. Highest values cluster in Bornova, Buca, and Kemalpas, a, coincident with fault-controlled sedimentary basins and permeable units. Spatial mapping highlights the dominant influence of lithology and fault proximity on radon distribution and underscores the limitations of uniform, national-scale mitigation policies. We advocate targeted, geology-aware health policies and urban-planning measures for monitoring and mitigation in geogenically vulnerable districts. These findings contribute to medical geology by providing region-specific evidence of radon risk in one of T & uuml;rkiye's most seismically active metropolitan areas. These outputs provide decision-ready evidence for monitoring, mitigation, and building-code updates in seismically active metropolitan settings.Article Citation - Scopus: 2The Uncertain Certainty of a Nightmare: What If Another Destructive Earthquake Strikes Izmir (türkiye)?(Mdpi, 2024) Salata, Stefano; Uzelli, TaygunOn 6 February 2023, near Kahramanmaras in south-central Turkiye, an event underscored the vulnerability of cities to seismic activity, revealing a lack of preparedness for substantial shocks. The contributing factors are manifold, yet fundamentally, the collapse of buildings and infrastructure can be attributed to an underestimated capacity for meticulous settlement planning (location) and the adoption of advanced techniques for resilient construction (structure). Regrettably, as has been investigated by many research works, ordinary urban planning in Turkiye hardly finds ways to integrate the vulnerability analysis for settlement expansion, which includes the full integration of geological characteristics with the analysis of building sensitivity. With this work, we wanted to build a composite risk index based on earthquake vulnerability, hazard amplification map, and exposure. We designed the composite index in Izmir's basin, Turkiye's third most populated city, to answer the question: What if a destructive earthquake strikes this densely settled area? The results illustrates how the coupled integration of digital data on geology with settlements and infrastructure in a Geographic Information System environment can be used to produce risk maps and plan the anthropic system's adaptation carefully. Findings demonstrate the city is highly vulnerable to earthquakes and identify priority areas for planning intervention, relocation, and renovation of buildings.Article Citation - WoS: 5Citation - Scopus: 5Are Soil and Geology Characteristics Considered in Urban Planning? an Empirical Study in Izmir (turkiye)(MDPI, 2023) Salata, Stefano; Uzelli, TaygunIt is well acknowledged that sustainable soil management can play a crucial role in reducing the vulnerability of urban areas, but are soil characteristics properly evaluated in the decision-making process concerning urbanization? Within this work, we conducted an analysis of the land-use change trends in the city of Izmir (Turkey). We made an extended and detailed analysis of the urbanization processes between 2012 and 2018 in a geographic information system environment (Esri ArcGIS 10.8.1 and ArcGIS Pro 3.0). Then, we superimposed by spatial overlay different soil characteristics: land capability, hydraulic conductibility, soil groups, and fault lines. We discovered that although there is a joint agreement on soil and its geological importance in reducing urban vulnerabilities to flooding, urban heat islands, agricultural production, or earthquakes, there is scarce knowledge of its characteristics to inform land-use planning. This work sheds some light on how newly developed areas are planned without proper consideration of soil properties, following a fuzzy and irrational logic in their distribution. Results encourage the utilization and inclusion of soil knowledge to support the decision-making process concerning urban transformation to achieve more resilient and less vulnerable urban systems.Article Citation - WoS: 11Citation - Scopus: 11Adapting Cities To Pluvial Flooding: the Case of Izmir (türkiye)(MDPI, 2022) Salata, Stefano; Couch, Virginia Thompson; Velibeyoğlu, Koray; Baba, Alper; Saygın, Nicel; Uzelli, TaygunIn the coming decades, climate change will be one of the most significant challenges for urban areas. The quantity, duration and intensity of events, such as flash rains and heat waves, will increase the vulnerability of urban regions while exposing citizens to potentially dangerous conditions. According to the current literature, mainstreaming resilience in urban planning means designing rules that strengthen urban systems’ adaptive and self-regulating functions by reducing their vulnerability. In this work, we aimed to build knowledge for the application of the sponge district concept to Izmir (Türkiye), one of Europe’s most vulnerable areas to pluvial flooding. To do this, we first analyzed the runoff in each urban sub-watershed, then employed a composite index to determine potential areas of intervention for nature-based solutions. Results show that 10% of Izmir’s urban areas are extremely vulnerable to cloudbursts, which means that 40% of the urban population is exposed to this phenomenon. Moreover, the runoff calculation in the sub-watershed demonstrated that the potential flood volume is underestimated, especially in the upslope areas. The results can be used as a template to suggest a stepwise approach to mainstream the resilience of densely-inhabited coastal urban catchments.Article Citation - WoS: 10Citation - Scopus: 10Hydrogeology and Hydrogeochemistry of the Geothermal Systems and Its Direct Use Application: Balçova-Narlıdere Geothermal System, İzmir, Turkey(Elsevier, 2022) Baba, Alper; Sözbilir, Hasan; Sayık, Tolga; Arslan, Sinan; Uzelli, Taygun; Tonkul, Serhat; Demir, Mustafa MuammerThe Balçova-Narlıdere geothermal system, located in western Turkey, is an extensional domain type geothermal play. Geological, hydrogeological, and geothermal studies have been done in the Balçova-Narlıdere geothermal field since 1960. As a result of these studies, production and research wells were drilled in the area by both the public and private sectors. Of the 37 wells drilled in the Balçova-Narlıdere geothermal field, 26 were drilled by İzmir Geothermal Energy Company Inc. (16 productions, 4 re-injection, 4 gradientst, 2 unused) and 11 by the İzmir Governorship Investment Monitoring and Coordination Department and companies in the private sectors. There are two reservoirs, one shallow and one deep, in the geothermal field. Well depths are less than 200 m in the shallow reservoir. The deep production wells have depths ranging from 400 to 1,100 m and reservoir temperatures reaching 140 °C. The electrical conductivity (EC) values in the shallow production wells range from 1,200 to 1,500 µS/cm. EC values in the deep production wells vary from 1,871 to 2,025 µS/cm, and all geothermal fluids in the field are mineral-rich waters. In the İzmir geothermal district heating system, the newest technologies are used, and operational costs are very low. İzmir Geothermal Energy Company Inc. has been operating since 1996 and has reached 38,460 residences. The current capacity of the system is approximately 160 MWt. Cooling systems continue to spread in Turkey, focusing on electric air conditioning systems and geothermal heating systems, but both economic and applicability problems have slowed the expansion of cooling systems. However, İzmir Geothermal Energy Company Inc. began operating its first geothermal cooling application in Balçova in 2018, cooling 1,900 m2 of the indoor area by lithium bromide absorption and 90/85 °C geothermal temperature regime by supplying 6/9 °C clean cold water to the coolers in the buildings. These results show that the extensional domain type geothermal system in the Balçova-Narlıdere region is suitable for both heating and cooling applicationsArticle Citation - WoS: 8Citation - Scopus: 8Structural Controls and Hydrogeochemical Properties of Geothermal Fields in the Varto(TÜBİTAK Scientific & Technological Research Council Turkey, 2021) Uzelli, Taygun; Sener, Mehmet Furkan; Dolek, Iskender; Baba, Alper; Sozbilir, Hasan; Dirik, Ramazan KadirVarto and the surrounding region have important geothermal fields, developing in strike-slip tectonic setting in East Anatolia, which resulted from the collision of the Arabian and Eurasian plates. The main structural elements in the area are the NE-trending sinistral and NW-trending dextral strike-slip fault segments and N-S trending extension zones. In order to determine fault-controlled geothermal circulation, it is very important to fully characterize the structural elements in these complex environments. The widely distributed volcanic rocks have fracture and crack systems that play an important role in surface infiltration, geothermal fluid, and groundwater circulation. Especially in areas where the fault segments intersect, hot springs outlets and natural resources easily come to the surface. In order to understand the flow paths of geothermal fluid along the faults in these geothermal systems, it is necessary to determine the stress state of the faults and to map the distribution of the structural elements. For this reason, we conducted a detailed study on the Varto Fault Zone, which has important geothermal fields in Eastern Anatolia. We present conceptual models of the geothermal fields in the Varto region that show favorable geothermal activity on the intersecting fault segments, fault bends, step-overs, and accompanying fracture-crack sets. As a result, we emphasize that the planes of strike-slip faults in transtensional areas are more favorable for secondary permeability and enhances the geothermal fluid circulation, and this can be supported by hydrogeochemical data.Article Citation - WoS: 4Citation - Scopus: 15Effects of Seismic Activity on Groundwater Level and Geothermal Systems in İzmir, Western Anatolia, Turkey: the Case Study From October 30, 2020 Samos Earthquake(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2021) Uzelli, Taygun; Bilgiç, Esra; Öztürk, Bahadır; Baba, Alper; Sözbilir, Hasan; Tatar, OrhanThe October 30, 2020 Samos earthquake (Mw 6.6) affected the Aegean Sea and environs, caused destruction and loss of life in the city of İzmir located 70 km away from the earthquake epicenter. Before this earthquake, water resources were monitored in the areas of Bayraklı, Gülbahçe, and Seferihisar. For this purpose, 10 groundwater monitoring wells were drilled in the Bayraklı area, where groundwater level, temperature, and electrical conductivity changes were monitored at 1-h intervals in 5 wells. Besides physical parameters such as groundwater levels, temperatures and electrical conductivities, hydrogeochemical cations, and anions measured in the study area. Change in the groundwater levels was observed before, during, and after the Samos earthquake. A trend of rising groundwater level was observed two days before the mainshock, to a height of 10 cm, and the level was maintained till the end of the earthquake. The water levels returned to its original height after about 7 to 10 days of the earthquake. Moreover, electrical conductivity (EC) values were changed because of the interaction with the surrounding rocks and well walls, mixing with different waters during the earthquake shaking. The essential anomalies were observed in the geothermal fields of Gülbahçe and Seferihisar. Due to this earthquake, new geothermal springs emerged along the NE-SW trending Gülbahçe and Tuzla faults, located about 50 to 20 km from the Samos earthquake epicenter, respectively. The new geothermal waters are in Na-Cl composition and similar to other geothermal springs in the region. While the recorded water temperatures in the new geothermal springs vary from 40 to 45 °C in Seferihisar, it was measured between 35 and 40 °C in Gülbahçe. Due to these anomalies, it is found essential to monitor the effect of the earthquake on the physical and chemical characteristics of the groundwater and its usefulness in earthquake predictions.Article Citation - WoS: 40Citation - Scopus: 44Geological and Hydrogeochemical Properties of Geothermal Systems in the Southeastern Region of Turkey(Elsevier Ltd., 2019) Baba, Alper; Şaroğlu, Fuat; Akkuş, I.; Özel, Nedret; Yeşilnacar, Mehmet İrfan; Nalbantçılar, Mahmut Tahir; Demir, Mustafa Muammer; Gökçen, Gülden; Arslan, Ş.; Dursun, N.; Uzelli, Taygun; Yazdani, HamidrezaThe Anatolia region is one of the most seismically active regions in the world. It has a considerably high level of geothermal energy potential thanks to its geological and tectonic settings. The Southeastern Anatolia Region (GAP) is located in the south of Bitlis-Zagros Suture Zone (BZSZ) which is in the Arabian foreland. During the neotectonic period, the folded structures have been developed under the influence of tectonic compression from the Upper Miocene in the GAP Region where it is closely related to active tectonics. These tectonic activities produce more geothermal resources. Few studies have been carried out in this region for geothermal energy. Limited portions of the geothermal resources have been used both for thermal tourism and greenhouses in the GAP region. The aim of this study is to determine geological, tectonic and hydrogeochemical properties of a geothermal system in the GAP Region. The result indicates that the surface temperatures of geothermal fluids are from 20 to 84.5 °C A large number of abandoned oil wells, whose temperature reaches 140 °C, are found in the region. Also, hydrogeochemical results show that deep circulated geothermal fluids are enriched with Na-Cl and shallow geothermal system fluids have Na−HCO 3 and Ca-SO 4 characters because of cold water mixing and water-rock interaction. Cold waters are generally of Ca-Mg−HCO 3 and Ca−HCO 3 type. Cation geothermometers were used for determining reservoir temperature of the geothermal resources in the region. The results show that the reservoir temperature of these geothermal resources ranges from 50 °C to 200 °C. The isotope data (oxygen-18, deuterium and tritium) suggests that geothermal fluid is formed by local recharge and deep circulation.Article Citation - WoS: 26Citation - Scopus: 25Conceptual Model of the Gülbahçe Geothermal System, Western Anatolia, Turkey: Based on Structural and Hydrogeochemical Data(Elsevier Ltd., 2017) Uzelli, Taygun; Baba, Alper; Mungan, Gamze Gül; Dirik, Ramazan Kadir; Sözbilir, HasanThe Gülbahçe Geothermal Field is located on the eastern margin of the Karaburun Peninsula, about 45 km from the city of İzmir, western Anatolia, Turkey. The stratigraphy of the study area is represented by a Miocene volcano-sedimentary succession, including several sedimentary and volcanic units. These units overlie the basement rocks of the Karaburun Platform and Bornova Flysch Zone which consist of sandstones, shales and carbonate blocks. These rock units are cut and deformed by a series of NW-SE- to NE-SW-trending faults, extending from Sığacık Bay to Gülbahçe Bay. Structural studies suggest that while most of the geothermal systems in western Anatolia are controlled by normal faults, the geothermal system at Gülbahçe is controlled by a strike-slip dominated shear zone, previously named the İzmir-Balıkesir Transfer Zone. Along the fault zone, associations of active fault segments accommodate deep circulation of hydrothermally modified sea water, and thus the resulting negative flower structure is the primary control mechanism for the geothermal system. Hydrogeochemical properties of the field show that surface temperature of fluid ranges from 30 to 34 °C. Geothermal fluids in Gülbahçe have high salinity (EC > 34 mS/cm) and low enthalpy. Piper and Schoeller diagrams indicate that geothermal fluid is in the NaCl facies. Chemical geothermometers suggest that the reservoir temperature is around 53–136 °C. The isotopic data (oxygen-18, deuterium and tritium) suggest that geothermal fluids are formed by local recharge and deep circulation of sea water.
