USING WAVE PREDICTIONS FOR PORT STRUCTURE DESIGNS

Ticari limanlar ve yat limanları, deniz taşımacılığı ve tekne turizmi açısından hayati önem taşımaktadırlar. Limanların tasarımında en önemli aşamalardan biri, konaklayan gemi ve teknelere güvenli bir demirleme sağlayacak olan liman koruma yapısının tasarımıdır. Liman koruma yapısı tasarımını etkileyecek dalga özelliklerini belirten dalga iklimi, göz önüne alınması gereken temel unsurdur. Dalga iklimin modellenmesi koruma yapısı tasarımın sağlıklı olabilmesi açısından büyük bir öneme sahiptir. Bugün dünyada olduğu gibi, Türkiye'de de dalga tahminleri, rüzgar ölçümlerine ya da modellerine dayanmaktadır. Ancak, Türkiye Kıyılarında dalga iklimi çalışmalarında kullanılabilecek ölçülmüş dalga verisi bulunmadığından tasarım sürecinde dalga modelleri tercih edilmektedir. Bu çalışmada Türkiye Kıyıları için geliştirilmiş üç boyutlu hidrodinamik taşıma modeli olan HYDROTAM-3D modelinin rüzgar ve dalga iklimi alt modelleri anlatılmakta ve uygulama çalışması olarak Edremit, Balıkesir bölgesinin rüzgar ve dalga iklimi sunulmaktadır Ports and marinas have a vital importance in sea transportation and boat tourism. In the design of these areas, one of the most important steps is the design of the coastal defence structure which provides the safe berthing of the ships and the boats calling ports and marinas. Wave climate providing information on the wave characteristics that will affect the design of the defence structure is the basic aspect of the design process. Modelling the wave climate is of great importance in reaching on sound coastal defence structure. Like the overall practice in the world, wave prediction studies in Turkey are based on either the data gained out of wave measurements or models. However, as there is no continuous wave measurement data along the Turkish coasts, models of wave climate are preferred in the design process. In this study, the wind and wave climate sub-models of HYDROTAM-3D, a three dimensional hydrodynamic transport model are used and and developed for Turkish coasts, and the results of a case study for Edremit, Balıkesir are discussed

Modeling of Hydrodynamics and Dilution in Coastal Waters

Sea outfall systems are preferred to refinery systems because of the assimilation capacity of the sea as an economical choice. If sea outfall systems are chosen, the location of the sea outfall is critical for preventing the return of wastewater to the coastal zone and recovery back into an ecosystem. On the basis of the regulation of water pollution control, bacterial concentration needs to be below a certain value in the protected area. The primary effects on dilution are coastal currents generated by wind and transport of wastewater in closed or semi-closed coastal regions, as found in Turkey. Accurate predictions of wind and wave climates and currents are critical in sea outfall planning. In this study, the wind climate is determined from the data provided by the Edremit and Ayvalık Meteorological Stations and European Centre for Medium-Range Weather Forecasts operational archive at the coordinates of 39.50° N–26.90° E. Wind, wave, and current roses are prepared by HYDROTAM-3D. CORMIX was used for the near-field dilution, and HYDROTAM-3D, a three-dimensional hydrodynamic transport model, was used for the far-field dilution of the pollutant. The results of near-field and far-field dilution modeling show that the sea outfall of Edremit–Zeytinli meets the legal regulations

NUMERICAL MODELING OF EXTENDED MILD SLOPE EQUATIONS

Dalgalar derin denizden sığ denize doğru ilerlerken, dalga sapması, kırınım sığlaşması, yansıma, dalga kırılması ve taban sürtünmesi kayıplarının etkileri sonucunda değişimlere uğramaktadırlar. Bu değişimleri benzeştirmek için bir sayısal model hazırlanmıştır. Sayısal modelde lineer olmayan parabolik yumuşak eğim eşitliği ile genişletilmiş yumuşak eğim eşitlikleri çözülmüştür. Genişletilmiş yumuşak eğim eşitliklerinin çözümüne lineer olmayan dalga hızı ve grup hızı dahil edilmiştir. Sayısal modelin çözümünde sonlu farklar ve sonlu hacim yöntemleri kullanılmıştır. Modelde uygulanan sonlu farklar çözümünde Mac Cormack Yöntemi ve Noktasal Gauss Seidel Yöntemi birarada kullanılarak yeni bir sayısal yaklaşım önerilmiştir. Geliştirilen model, yarı dairesel sığlaşma, eliptik sığlaşma ve kıyıya paralel dalgakıran bulunan su alanlarında test edilip gerçekliği sınanmış ve Türkiye kıyılarında yeralan Fethiye Körfezi ve Obaköy kıyısal alanına uygulanmıştır.Waves transform from deep water to the shallow water. These transformations occur as a result of wave refraction, wave diffraction, wave shoaling, reflection, dissipation due to wave breaking and bottom friction. A numerical model has been developed to simulate these transformations. Nonlinear parabolic mild slope equation and extended mild slope equations have been used in the solution of the numerical model. Nonlinear celerity and group velocity have been included in the solution of the extended mild slope equation. Finite difference and finite volume methods have been used in the solution of the numerical model. Mac Cormack Method and Point Gauss Seidel Method have been applied together in the proposed new solution approach. The numerical model has been tested on the semicirular shoaling, elliptic shoaling and shore parallel breakwater diffraction. Model has been applied to Fethiye Bay and Obaköy coastal areas in Turkish coastline

Estimation of surface runoff to havran dam lake by using SWMM

Yağışlardan dolayı meydana gelen yüzeysel akışın tahmin edilmesi, su kaynaklarıyla ilgili çalışmaların temelidir. Bu sebeple, yağış akış sürecinin benzetimi amacıyla MIKE, BASIN ve SWMM gibi modeller geliştirilmiştir. Yağış türü, miktarı, süresi, sıcaklık, nem ve rüzgâr gibi meteorolojik faktörlerin yanında, havzadaki arazi kullanım türleri, toprak yapısı, eğim, drenaj güzergâhı ile havzada bulunan göl, rezervuar ve su yapıları gibi fiziksel faktörler de yüzeysel akışa etki eder. Bu çalışmada, 2002 yılında taşkın koruma amacıyla inşa edilmiş olan Havran barajını besleyen Havran çayının havzası (Balıkesir), sayısal yükseklik haritaları ve coğrafi bilgi sistemleri (CBS) araçları kullanılarak belirlenmiştir. Sayısal yükseklik modelleri (SYM/DEM), arazi şekli ve yükseltileri, akarsu drenajı, deseni ve çizgiselliklerini analiz etmek için kullanılmıştır. Drenaj havzası, fiziksel, hidrolojik ve arazi kullanımı parametrelerine göre bölümlendirilmiştir. Alt havzaların belirlenmesinde arazilerin, yükseklik modelleri ve jeolojik haritaları yanında güncel durumunu gösteren 2018 yılı CORINE sayısal haritaları da kullanılmıştır. Havzayı oluşturan alt bölümler sayısallaştırılarak, topografya akış yönü ve birikiminin tespit edilmesi ile yüzeysel akış miktarları hesaplanmıştır. EPA-SWMM, Amerika Birleşik Devletleri Çevre Koruma Ajansı - Taşkın Yönetim Modeline göre yağış akış sürecinin modeli oluşturulmuştur. Model, alt havzayı uniform eğime sahip, ortalama genişlikte bir arazi olarak varsayarak, yüzeyde oluşan yüzeysel akışın drenaj havzasına aktarıldığı kabulleri ile hesap yapmaktadır. Buna göre yağış ile gelen su miktarından buharlaşma ve sızma sonucu oluşan kayıplardan sonra kalan miktarı yüzeysel akış eşitliklerinde kullanılmaktadır. Bölgedeki meteoroloji istasyondan elde edilen 5 yıllık veriler ile ortalama günlük yağış miktarları hesaplanmıştır. Sıcaklık, nem, buharlaşma gibi diğer meteorolojik veriler SWMM modelini oluşturmak için kullanılmıştır. Hazırlanan SWMM modeli kullanılarak oluşması muhtemel yüzeysel akış değerleri bu model ile belirlenmiş ve baraja dökülmesi muhtemel mevsimsel yüzeysel akış tahmini yapılmıştır.Estimating the surface runoff due to precipitation is the basis of studies on water resources. Consequently, researchers have developed models such as MIKE, BASIN and SWMM, to simulate the precipitation and surface flow processes. Besides the meteorological factors such as precipitation type, amount, duration, temperature, humidity and wind, physical factors such as land use types, soil structure, drainage route and its slopes, lakes, reservoirs and the water structures in the basin also affect the surface flow. In this study,the drainage basin of Havran dam, Balıkesir, which is built in 2002 for the purpose of flood protection, is drawn by using numerical altitude maps and geographic information systems (GIS) tools. The study uses digital elevation models (DEM) to analyze land shapes, elevations, stream patterns and lineaments. It divides the drainage basin into subcatchments according to spatial identifiers such as physical and hydrological data, and by taking into consideration land use parameters. In the determination of the subcatchments, CORINE numerical maps showing the land use status of year 2018 as well as SYM/DEM and geological maps are used. The surface flow rates are calculated via digitizing the topography of the subcatchments, flow direction and flow accumulation. A model of surface flow process is built by using EPA-SWMM, United States Environmental Protection Agency – Storm Water Management Model. The model assumes the subcatchment as a surface with uniform slope and average width. Accordingly, the remaining amount after evaporation and seepage losses from precipitation is the surface flow transferred to the drainage system. By using this model, the seasonal surface flow drained into the lake is simulated according to the rainfall intensity and other meteorological data such as temperature, humidity, evaporation obtained from the regional stations

Sıcak su deniz deşarjlarının yakın alan dağılımının modellenmesi

The main cause of heated water discharges is the use of seawater as a coolant by power plants and industrial manufacturers. Uncontrolled discharges into the ambient sea water having excess heat, have an adverse effect on the ecosystems. In this study, the near field dilution of heated sea water discharges was modeled and the behaviors of pollutant clouds were analyzed using CORMIX (CORMIX2) and Visual Plumes. Following effects of different parameters (total effluent discharge, diffuser length, port details, current) on the near field dilution of heated discharges were investigated with different scenarios waters by numerical models CORMIX2 and Visual Plumes. Sensitivity analysis of the discharge parameters were made comparatively. In spite of a hypothetical study, a real coastal area was selected to obtain and discuss realistic conditions. Therefore Samsun coastal area in summer condition was selected and CORMIX2 and Visual Plumes were applied to determine the effects of discharge parameters on near field dilution

Web-Based Tsunami Early Warning System: A Case Study of the 2010 Kepulaunan Mentawai Earthquake and Tsunami

This study analyses the response of the Global Disasters Alerts and Coordination System (GDACS) in relation to a case study: the Kepulaunan Mentawai earthquake and related tsunami, which occurred on 25 October 2010. The GDACS, developed by the European Commission Joint Research Center, combines existing web-based disaster information management systems with the aim to alert the international community in case of major disasters. The tsunami simulation system is an integral part of the GDACS. In more detail, the study aims to assess the tsunami hazard on the Mentawai and Sumatra coasts: the tsunami heights and arrival times have been estimated employing three propagation models based on the long wave theory. The automatic alert level for the earthquake was given between Green and Orange Alert, which, in the logic of GDACS means no need or moderate need of international humanitarian assistance; however, the earthquake generated 3 to 9 m tsunami run-up along southwestern coasts of the Pagai Islands where 431 people died. The post event calculations indicated medium-high humanitarian impacts.JRC.G.2-Global security and crisis managemen

Incidence, etiology, and antibiotic resistance patterns of Gram-negative microorganisms isolated from patients with ventilator-associated pneumonia in a medical-surgical intensive care unit of a teaching hospital in Istanbul, Turkey (2004-2006)

The identification of microorganisms causing ventilator-associated pneumonia (VAP) is important for formulating appropriate therapies. In this study, we report the incidence, etiology, and antibiotic resistance patterns of Gram-negative microorganisms isolated from patients diagnosed with VAP in our medical-surgical intensive care unit (ICU) during the years 2004-2006. VAP was diagnosed by using the clinical criteria of the Centers for Disease Control and Prevention. Antibiotic resistance patterns of isolated microorganisms were defined by standard methods. The VAP incidence rate was 22.6/1,000 ventilator days. The most frequently isolated pathogens were Acinetobacter spp., methicillin-resistant Staphylococcus aureus, and Pseudomonas aeruginosa. Ninety percent of Acinetobacter spp. isolates were resistant to ceftazidime, 64% to imipenem, and 80% to ciprofloxacin. Fifty-nine percent of P. aeruginosa isolates were resistant to ceftazidime, 32% to imipenem, and 62% to ciprofloxacin. Cefoperazone-sulbactam was the most active agent against Acinetobacter spp. In conclusion, the incidence of VAP and the prevalence of multidrug-resistant microorganisms are quite high in our ICU. Comparison of the resistance rates of isolates demonstrates that certain antibiotic agents are more effective than others