Ortalama Su Seviyesi Değişimlerinin Taş Dolgu Kıyı Koruma Yapılarının Tasarımına ve Performansına Etkisi

Gel-git, mevsimsel değişiklikler, dalga kabarması/alçalması, fırtına kabarması ve küresel ısınmaya bağlı su seviyesi değişimleri sonucunda ortalama su seviyesinde gözlenen değişimler, taş dolgu kıyı koruma yapılarının tasarımlarının ve performanslarının değerlendirilmesi ile doğrudan ilgilidir. Bu tip yapılar için en kritik su seviyesi, yaygın olarak en yüksek su seviyesi tanımı ile kullanılmaktadır. Ancak, Kıyı Yapıları Planlama ve Tasarım Teknik Esasları’nda [1] koruma yapısında kullanılacak taşların kütlelerinin belirlenmesi için en kritik su seviyesinin en düşük su seviyesi ile en yüksek su seviyesi arasında ortaya çıkabileceği belirtilmiştir. Bu çalışmada taş dolgu kıyı koruma yapılarının tasarım derinliğinin belirlenmesinde kullanılan farklı yaklaşımların koruma tabakası taş kütlesi ile serbest kret kotuna olan etkisi incelenmiştir. Bu amaçla Karadeniz, Ege Denizi ve Akdeniz’de birer proje alanı seçilmiş ve bu projelerdeki yapıların ekonomik ömürleri boyunca gözlenebilecek tüm su seviyelerinde koruma tabakası taş kütlesi ile serbest kret kotu hesaplanmıştır. Seçilen projeler için daha düşük su seviyelerinde daha yüksek su seviyelerine göre %60’a varan oranlarda daha büyük taş kütlesi bulunmuştur. Çalışma sonuçları, en yüksek su seviyesinden daha kritik bir su seviyesinin, düşük su seviyesi ile en yüksek su seviyesi arasındaki herhangi bir su seviyesinde de oluşabileceğine örnek oluşturmaktadır. Buna bağlı olarak, seçilen kritik su seviyesi değeri ile koruma tabakası taş kütlesi hesaplama yöntemlerinin ilişkisi tartışılmış ve yapının ekonomik ömrü boyunca oluşabilecek tüm su seviyelerinin tasarım derinliği belirlenirken göz önünde bulundurulması önerilmiştir.&nbsp;</p

Kıyılarda iklim değişikliğine karşı kumlanma modeli destekli kırılganlık analiz projesi-KIDEKA

TÜBİTAK MAG15.03.201

The Coastal Circulation Model of Büyük Menderes River and Adjacent Coastal Areas

In this study, circulation model of Büyük Menderes River and the adjacent coastal areas willbe presented. Büyük Menderes runs through the second biggest alluvial plains in Turkey anddischarges into the Aegean Sea where fishing and tourism are main income for the region.Therefore, an accurate representation of water circulation is important both for the waterquality in the bay and the morphodynamics at the coast of Büyük Menderes Delta.Finite Volume Coastal Ocean Model (FVCOM) is used for the circulation modelling mainlybecause use of unstructured grid mesh enables modeling of a larger coastal water body withhigher resolution at river discharge region, efficiently. The model is set-up to assess thepatterns under the forcing of Coriolis, tide, wind, wave (SWAN integration) and river.Results of model runs for March (rainy season) and October (dry season) 2017 will bepresented with comparisons to in situ data(Figure 1). In situ data used in the modelincludes salinity and temperature of seawater and river, river discharge, windcharacteristics, water levels and currentmeasurements at three locations, which wascollected as part of a research projectcampaign funded by The Scientific andTechnological Research Council of Turkey(TUBITAK).These results are going to be used for calibration of the model and it is the first step ofdeveloping regional circulation model for long term scenarios and future changes

Effects of Deep Water Source Sink Terms in 3rd generation Wave Model SWAN using different wind data in Black Sea

Coastal development in Black Sea has increased in recent years. Therefore, careful monitoring of the storms and verification of numerical tools with reliable data has become important. Previous studies by Kirezci and Ozyurt (2015) investigated extreme events in Black Sea using different wind datasets (NCEP's CFSR and ECMWF's operational datasets) and different numerical tools (SWAN and Wavewatch III). These studies showed that significant effect to results is caused by the deep water source-sink terms (wave growth by wind, deep water dissipation of wave energy (whitecapping) and deep water non-linear wave-wave interactions). According to Timmermans(2015), uncertainty about wind forcing and the process of nonlinear wave-wave interactions are found to be dominant in numerical wave modelling. Therefore, in this study deep water source and sink term solution approaches of 3rd generation numerical tool (SWAN model) are tested, validated and compared using the selected extreme storms in Black Sea. 45 different storms and storm like events observed in Black Sea between years 1994-1999 are selected to use in the models. The storm selection depends on the instrumental wave data (significant wave heights, mean wave period and mean wave direction) obtained in NATO-TU Waves project by the deep water buoy measurements at Hopa, Sinop, Gelendzhik, and wind data (mean and peak wind speeds, storm durations) of the regarding events. 2 different wave growth by wind with the corresponding deep water dissipation terms and 3 different wave -wave interaction terms of SWAN model are used in this study. Wave growth by wind consist of two parts, linear growth which is explained by Cavaleri and Malanotte-Rizzoli(1981),and dominant exponential growth. There are two methods in SWAN model for exponential growth of wave, first one by Snyder et al. (1981), rescaled in terms of friction velocity by Komen et. al (1984) which is derived using driving wind speed at 10m elevation with related drag coefficient (WAM Cycle 3).The second method follows the quassi linear wind-wave theory by Janssen(1989,1991) which also considers the atmospheric boundary layer effects and the roughness length of the sea surface (WAM Cycle 4).(SWAN Technical Documentation,2015) The dissipation caused by whitecapping depends on the steepness of the waves. There are two different steepness dependent coefficient configurations in SWAN model corresponding to the selected wind-wave interaction formulations which are mentioned above (Komen and Janssen approaches). Lastly ,there are 3 options for defining deep water non-linear wave-wave interaction, which are DIA(Discrete Interaction Approximation)by Hasselman (quadruplets), XNL(which is based on the original six-dimensional Boltzmann integral formulation of Hasselmann), and multiple DIA which considers up to 6 wave number configurations by Hashimoto et al. (2002).(SWAN Technical Documentation,2015) In this study, 540 test cases are modelled using all possible selections of deep water source and sinks approaches available in SWAN model. The computed results are compared with buoy measurements. The uncertainty due to different source sink selections are quantified using different statistical analysis. Preliminary results show that some of the term configurations predict the significant wave height (Hs) less than actual values measured at the buoy locations. One of the reasons of the underestimation of the wave parameters could be the lower wind speed estimated in closed basins and the other one is the uncertainties in the wind-sea interaction. All of the results, comparisons and discussions will highlight the best source sink approach to be used to model extreme wave events in Black Sea. References Kirezci C., Ozyurt G., (2015), "Comparison of Wave Models in Black Sea", UK YCSEC 2015, 21-23 March 2015, Manchester Özhan, E. and Abdalla, S.,(1999)"Wind and Wave Climotology of the Turkish Coast and the Black Sea:An Overview of the NATO TU-WAVES Project.",p.1-20. SWAN Team.,(2015)," SWAN Scientific and Technical Documentation,SWAN Cycle III version 41.01AB", Delft University of Technology Timmermans, B.,(2015), "Uncertainty In Numerical Wind-Wave Models", Doctoral dissertation of University of Southampto

Application of Sea Level Rise Vulnerability Assessment Model to Selected Coastal Areas of Turkey

Climate change and anticipated impacts of sea level rise such as increased coastal erosion, inundation, flooding due to storm surges and salt water intrusion to freshwater resources will affect all countries but mostly small island countries of oceans and low-lying lands along coastlines. Turkey having 8333 km of coastline including physically, ecologically and socio-economically important low-lying deltas should also prepare for the impacts of sea level rise as well as other impacts of climate change while participating in mitigation efforts. Thus, a coastal vulnerability assessment of Turkey to sea level rise is needed both as a part of coastal zone management policies for sustainable development and as a guideline for resource allocation for preparation of adaptation options for upcoming problems due to sea level rise. As a scientific approach to coastal vulnerability assessment a coastal vulnerability matrix and a corresponding coastal vulnerability index of a region to sea level rise are developed. In the development of the matrix and the index, indicators of impacts of sea level rise which use commonly available data are used. The developed coastal vulnerability assessment model is used to determine the vulnerability of three different coastal areas or Turkey; Goksu Delta (Specially Protected Area), Gocek (Specially Protected Area) and Amasra to present the sensitivity of the model to regional properties

Improving Coastal Vulnerability Assessments to Sea-Level Rise: A New Indicator-Based Methodology for Decision Makers

Integration of impacts of sea-level rise to coastal zone management practices are performed through coastal vulnerability assessments. Out of the types of vulnerability assessments, a proposed model demonstrated that relative vulnerability of different coastal environments to sealevel rise may be quantified using basic information that includes coastal geomorphology, rate of sea-level rise, and past shoreline evolution for the National Assessment of Coastal Vulnerability to Sea-Level Rise for U.S. Coasts. The proposed methodology focuses on identifying those regions where the various effects of sea-level rise may be the greatest. However, the vulnerability cannot be directly equated with particular physical effects. Thus, using this concept as a starting point, a coastal vulnerability matrix and a coastal vulnerability index that use indicators of impacts of sea-level rise are developed. The developed model compares and ranks different regions according to their vulnerabilities while prioritizing particular impacts of sea-level rise of the region. In addition, the developed model determines most vulnerable parameters for adaptation measures within the integrated coastal zone management concept. Using available regional data, each parameter is assigned a vulnerability rank of very low to very high (1-5) within the developed coastal vulnerability matrix to calculate impact sub-indices and the overall vulnerability index. The developed methodology and Thieler and Hammar-Klose the proposed methodology were applied to the Goksu Delta, Turkey. It is seen that the Goksu Delta shows moderate to high vulnerability to sea levelsea-level rise. The outputs of the two models indicate that although both models assign similar levels of vulnerability for the overall region, which is in agreement with common the literature, the results differ significantly when in various parts of the region is concerned. Overall, the proposed Thieler and Hammar-Klose method assigns higher vulnerability ranges than does the developed coastal vulnerability index sea-level rise (CVI-SLR) model. A histogram of physical parameters and human influence parameters enables enable decision makers to determine the controllable values using the developed model

CALIBRATION AND EVALUATION OF THE 3RD GENERATION WAVE MODEL WAVEWATCH III UNDER EXTREME CONDITIONS IN EASTERN MEDITERRANEAN AND AEGEAN SEA

In the previous studies Poseidon Buoy data are used for both calibration and validation forthird generation wave models in Aegean Sea. However, due to spatial resolution limits(caused by huge computational time of wave model), there is problem with the bathymetry.This problem is caused by complex orography of Aegean Sea and existence of islands.Depth of Poseidon buoys are under 20m and it is not possible to obtain these depths forany of Poseidon buoys with a spatial resolution that is applicable for calibration. Depth ofbuoy is critical since it effects directly the calibration considering results of wave model andbuoy are taken for different depths.In this study, both Poseidon Buoy and Buoys of Turkish General Directorate of Meteorology(MGM) are used. MGM buoys started recording at 2015 March and they are stilloperational. Two of MGM buoys are located in Eastern Mediterranean which gives us thechance to make a calibration for eastern Mediterranean Sea. As far as our knowledge thereis no calibration study in eastern Mediterranean using buoy data. One of MGM Buoy at theAegean Sea is located at deeper location (70m depth) which provides healthier calibrationin Aegean Sea. In this conference the performance of Wavewatch III for January 2018Storm and December 2016 Storm will be discussed