Browsing by Author "Ozturk, Sevki"

Now showing 1 - 5 of 5

Citation - WoS: 2
Citation - Scopus: 1
Comparative Landslide Susceptibility Mapping Using Local Inventories: a Case Study From Trabzon, Türkiye
(Springer, 2025) Ozturk, Sevki; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
This paper presents a novel approach to landslide susceptibility mapping by integrating two landslide inventories prepared by different national agencies of T & uuml;rkiye (MTA and AFAD) in the Trabzon region. By leveraging these different inventories, the study aims to offer a more comprehensive understanding of landslide risks, addressing limitations in previous susceptibility models that typically rely on single inventory sources. Employing the frequency ratio method, the paper generates susceptibility maps from each database to examine the influence of landslides across various environmental factors. Additionally, an Analytical Hierarchy Process (AHP)-based map, incorporating environmental characteristics, literature, and expert opinions, is developed to provide a third perspective, independent of historical landslide data. The results indicate that AHP model classifies approximately 19.20% of the study area as very high and high susceptibility. In contrast, the MTA and AFAD models assign only 12.40% and 8.80% to high and very high categories, with most areas falling into low to moderate susceptibility. Comparisons with the Global Landslide Hazard Map further highlight the strengths and limitations of localized versus global assessments. This study contributes to the field by demonstrating the benefits of a dual-inventory approach, enhancing the precision of landslide susceptibility maps and providing valuable insights for disaster risk management and sustainable land-use planning.
Citation - WoS: 12
Citation - Scopus: 15
Debris Flow Modelling and Hazard Assessment for a Glacier Area: a Case Study in Barsem, Tajikistan
(Springer, 2023) Dincer, A. Ersin; Kalpakci, Volkan; Ozturk, Sevki; Yilmaz, Kutay; 163874; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
This study analyses a previous debris flow hazard as a consequence of emerging risks related to climate and regional physical changes. In addition to the increasing flood frequencies, there is an increasing risk of mud or debris flow due to increasing temperature and heavy precipitation resulting in glacier melting. One of the most recent dramatic examples of the debris flow incident took place in Barsem, Tajikistan, in 2015. As a result of heavy precipitation and excess temperature, the melting of glaciers caused debris flow which ended up with a catastrophic damage at Barsem Town. In this study, a methodology for modelling debris flow and related hazard is developed by examining the 2015 incident in detail with a commercially available software, Hydrological Engineering Centre-River Analysis System (HEC-RAS). Simulations and hazard assessment of the incident suggest that assessment of debris flow hazard can be implemented similar to flood hazard. Moreover, it is seen that debris flow inundation area can be predicted accurately by low-resolution free-source digital elevation models (DEMs), while in the present work they could not predict the debris flow hazard assessment accurately. Sensitivity results also reveal that free-source DEMs with higher resolutions do not necessarily give better predictions than free-source DEMs with lower resolutions.
Citation - WoS: 12
Citation - Scopus: 13
Effect of Urbanization on Surface Runoff and Performance of Green Roofs and Permeable Pavement for Mitigating Urban Floods
(Springer, 2024) Ozturk, Sevki; Yilmaz, Kutay; Dincer, A. Ersin; Kalpakci, Volkan; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Floods are increasingly becoming a significant concern due to climate change, global warming, and excessive urbanization. The Intergovernmental Panel on Climate Change (IPCC) has projected that global warming will continue to contribute to more frequent and severe floods and hydrological extremes. In response to these challenges, nature-based solutions (NBSs) have gained recognition as effective approaches to mitigate the adverse impacts of floods by focusing on ecosystem conservation, restoration, and sustainable utilization of natural resources. This study examines a flood that occurred in the Erkilet District of Kayseri, T & uuml;rkiye on September 22, 2022, as a result of intense rainfall. It involves a thorough on-site investigation to assess the hydraulic, hydrologic, and geotechnical attributes of the study area. The findings from the field study indicate that the primary cause of the flood is attributed to excessive urbanization. To further analyze the impact of urbanization, a hydraulic model is developed considering both the physical and topographical conditions of the study area for both the year 2006 and 2022. The simulation results reveal that the extent of inundation area and water depth has increased significantly due to the excessive urbanization that occurred within a 16-year period. Additionally, the effectiveness of green roofs and permeable pavements as NBSs to mitigate urban flooding is explored. The implementation of green roofs and permeable pavements shows promising results, reducing the adverse effects of urban floods by 3% to 8%, depending on their specific locations and configurations. However, the results suggest that NBSs alone cannot fully prevent floods so they should complement gray infrastructure. The novelty of the study lies in its ability to demonstrate the impact of urbanization and the effectiveness of nature-based solutions in mitigating flood extent based.
Liquefaction Hazard Assessment in a Gis Environment: a Case Study of Buğday Pazarı Neighborhood in Çankırı Province
(Techno-press, 2024) Ozturk, Sevki; Sarifakioglu, Ender; Yurdakul, Eren; 163874; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Seismic movements have varying effects on structures based on characteristics of local site. During an earthquake, weak soils are susceptible to damage due to amplified wave amplitudes. Soil -structure interaction issue has garnered increased attention in T & uuml;rkiye, after devastating earthquakes in Kocaeli G & ouml;lc & uuml;k (1999), Izmir (2020), Kahramanmara Pazarc & imath;k and Elbistan (2023). Consequently, liquefaction potential has been investigated in detail for different regions of T & uuml;rkiye, mainly with available field test results. & Ccedil;ank & imath;r & imath;, a city located close to North Anatolian Fault, is mainly built on alluvium, which is prone to liquefaction. However, no study on liquefaction hazard has been conducted thus far. In this study, groundwater level map, SPT map, and liquefaction risk map have been generated using Geographical Information System (GIS) for the Bu & gbreve;day Pazar & imath; District of & Ccedil;ank & imath;r & imath; province. Site investigations studies previously performed for 47 parcels (76 boreholes) were used within the scope of this study. The liquefaction assessment was conducted using Seed and Idriss's (1971) simplified method and the visualization of areas susceptible to liquefaction risk has been accomplished. The results of this study have been compared with the City Council's precautionary map which is currently in use. As a result of this study, it is recommended that minimum depth of boreholes in the region should be at least 30m and adequate number of laboratory tests particularly in liquefiable areas should be performed. Another important recommendation for the region is that detailed investigation should be performed by local authorities since findings of this study differ from currently used precautionary map.
A Sustainable Decision-Making Framework To Evaluate Land and Seaside Disposal Options for Tunnel Spoil: A Case Study of Trabzon
(Science Press, 2025) Dincer, Ali Ersin; Demir, Abdullah; Ozturk, Sevki; Yilmaz, Kutay; 06.05. İnşaat Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
Sustainable urbanization is essential for developing cities. To ensure the success of planned construction projects, designers must prioritize sustainability by lowering emissions and reducing costs. Tunnel projects are common worldwide, but disposing of the excavated material presents a significant challenge due to unsuitable geographic conditions. While coastal cities with mountainous terrains have historically used spoil for sea filling, this study offers alternative landside options to promote sustainability. By using a conventional analytical hierarchy process (AHP) method for multi-criteria decision-making (MCDM), the study evaluates land use, sustainability, slope, and drainage lines as constraints for the AHP method. The transportation-related greenhouse gas (GHG) emissions are also considered to reduce environmental damage. Particle swarm optimization is used to determine the minimum transportation distance from the excavation zone to the dumpsite. As a sub-criteria of land use, the seaside is also considered a dumpsite compared with other options on the land side. The spatial analysis results of the case study show that suitable landside sites are available for the Trabzon tunneling project. Although coastal areas in Trabzon have been used for spoil dumping for filling purposes in the past, landside deposition is a viable alternative. The suitability ranks of land and coastal filling options are relatively similar, and selecting the seaside as the dumpsite for the Trabzon tunneling project reduces CO2 emissions. By adopting sustainable practices, we can realize a better future for our cities and the environment.