Person: KANKAL, MURAT
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KANKAL
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MURAT
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Publication Trend detection by innovative polygon trend analysis for winds and waves(Frontiers Media Sa, 2022-08-10) Akcay, Fatma; Bingölbali, Bilal; BİNGÖLBALİ, BİLAL; Akpınar, Adem; AKPINAR, ADEM; Kankal, Murat; KANKAL, MURAT; İnegöl Meslek Yüksekokulu; İnşaat Mühendisliği Bölümü; 0000-0003-4496-5974; 0000-0002-9042-6851; 0000-0003-0897-4742; AAZ-6851-2020; AAC-6763-2019It is known that densely populated coastal areas may be adversely affected as a result of the climate change effects. In this respect, for coastal protection, utilization, and management it is critical to understand the changes in wind speed (WS) and significant wave height (SWH) in coastal areas. Innovative approaches, which are one of the trend analysis methods used as an effective way to examine these changes, have started to be used very frequently in many fields in recent years, although not in coastal and marine engineering. The Innovative Polygon Trend Analysis (IPTA) method provides to observe the one-year behavior of the time series by representing the changes between consecutive months as well as determining the trends in each individual month. It is not also affected by constraints such as data length, distribution type or serial correlation. Therefore, the main objective of this study is to investigate whether using innovative trend methods compared to the traditional methods makes a difference in trends of the climatological variables. For this goal, trends of mean and maximum WS and SWH series for each month at 33 coastal locations in Black Sea coasts were evaluated. Wind and wave parameters WS and SWH were obtained from 42-year long-term wave simulations using Simulating Waves Nearshore (SWAN) model forced by the Climate Forecast System Reanalysis (CFSR). Monthly mean and maximum WS and SWH were calculated at all locations and then trend analyses using both traditional and innovative methods were performed. Low occurrence of trends were detected for mean SWH, maximum SWH, mean WS, and maximum WS according to the Mann-Kendall test in the studied months. The IPTA method detected more trends, such as the decreasing trend of the mean SWH at most locations in May, July and November December. The lowest (highest) values were seen in summer (winter), according to a one-year cycle on the IPTA template for all variables. According to both methods, most of the months showed a decreasing trend for the mean WS at some locations in the inner continental shelf of the southwestern and southeastern Black Sea. The IPTA method can capture most of the trends detected by the Mann-Kendall method, and more missed by the latter method.Publication Increasing trends in spectral peak energy and period in a semi-closed sea(Pergamon-elsevier Science Ltd, 2023-02-13) Acar, Emine; Akpınar, Adem; AKPINAR, ADEM; Kankal, Murat; KANKAL, MURAT; Amarouche, Khalid; AMAROUCHE, KHALID; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0002-9042-6851; 0000-0003-0897-4742; 0000-0001-7983-4611; JTU-9268-2023; AAC-6763-2019; AAZ-6851-2020; AFR-7886-2022This study aims to investigate long-term trends in the Black Sea's spectral wave peak energy and periods. Improved Visualization of the Innovative Trend Analysis and the Mann-Kendal methods was applied to the maximum and mean spectral peak energies and peak periods between 1979 and 2020. Long-term spectral data are obtained from the ERA5 reanalysis and two spectral wave models, SWAN and WWIII. The innovative trend analysis method has the particularity to examine trends in higher and lower value categories. Studies of long-term changes in spectral wave characteristics are rare, and trends in spectral peak parameters are evaluated in this study for the first time in the Black Sea. It was detected that both spectral peak energies and peak periods tend to increase predominantly over most of the time scales. Furthermore, while the change rates for peak en-ergies do not exceed 40% annually and seasonally, change rates exceeding 100% are observed on a monthly basis. Besides, the change rates of the peak periods vary in the +/- 5% band and usually do not exceed 15%. Moreover, despite a few differences, trend analysis results obtained using SWAN and WWIII models were close to the global ERA5 results. The results may provide insight into the design and durable development of coastal and marine structures as well as the evaluation of wave climate change based on spectral wave data.Publication Innovative approaches to the trend assessment of streamflows in the Eastern Black Sea basin, Turkey(Taylor & Francis Ltd, 2022-01-20) San, Murat; Akçay, Fatma; Kankal, Murat; KANKAL, MURAT; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0003-0897-4742; AAZ-6851-2020The issue of detection of hydrometeorological trends remains relevant because of the importance of climate change in design, operation, and management studies related to water resources. This study examines the effects of changes in climate and land use on monthly flows (1962-2018) in the Eastern Black Sea basin, Turkey, using innovative trend analysis methods. In this context, innovative polygon trend analysis (IPTA) and innovative trend significance test (ITST) were used to detect the trends and compared with Mann-Kendall test. Only stations with homogeneous data that did not experience non-climatic changes are used in the analysis. IPTA and ITST approaches are much more sensitive than Mann-Kendall in detecting trends. Although the innovative methods are mostly compatible with each other (90%), IPTA presents additional information about trend transitions between successive parts of time series. Results indicate significant decreasing trends in summer months, likely due to diminishing precipitation and effective evaporation.Publication A downscaling application for local meteorological variables of Eastern Black Sea Basin and scenario based predictions(Turkish Chamber Civil Engineers, 2022-11-01) Nacar, Sinan; Okkan, Umut; KANKAL, MURAT; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0003-0897-4742; AAZ-6851-2020Climate change has become one of the most important problems discussed around the world due to its environmental, economic and social impacts. In order to determine the magnitude of the impact of climate change and possible adaptation studies, it is necessary to determine the changes in the future periods of temperature and precipitation being the most important variables of the climate. For this purpose, scenario outputs of general circulation models (GCM) with coarse spatial resolution are used. The low resolution of these outputs limits their direct use in determining the effects of climate change on a local scale. Therefore, GCM outputs should be downscaled into finer scale. The aim of this study is to determine the possible effects of climate change on precipitation and temperature values of Eastern Black Sea Basin (EBSB), which is one of the most important hydrological basin in Turkey. For this purpose, the coarse resolution outputs of the GFDL-ESM2M model under RCP4.5 and RCP8.5 scenarios were reduced to local scale using the multivariate adaptive regression splines (MARS) and classical regression analysis (CRA) methods. Various performance statistics were used to compare the downscaling capabilities of MARS and CRA based models, and the method with the highest performance was determined according to these statistics. Within the scope of the study, the monthly average temperature and total precipitation values for the next period (2021-2050, 2051-2080, 2081-2100) of 12 meteorology stations located in and around the basin were produced by using MARS-based models that give the best performance values. Mann-Kendall trend analysis was also applied to the scenario data obtained. According to the results, it is expected that the temperature values in the southern part of the basin with terrestrial climate characteristics (Bayburt, Gumushane, Susehri ve Sebinkarahisar stations) will increase by an average of 1 degrees C according to the RCP4.5 scenario and 1.5 degrees C according to the RCP8.5 scenario in the period 2021-2050. In addition, temperature increases of up to 2.5 degrees C are foreseen on the coastline of the basin where the Pazar, Rize and Hopa stations are located. According to the outputs of both scenarios, is expected in long-term precipitation average values in almost all of the basin. In the periods of 2051-2080 and 2081-2100, it is foreseen that the increases and decreases in temperature and precipitation values will be more than the 2021-2050 period. According to the results of the trend analysis, the RCP4.5 scenario for temperature and precipitation, no trend is expected in the future, while according to the RCP8.5 scenario, an increase trend for temperature and a decrease trend for precipitation have been determined.Publication Geo-spatial multi-criteria evaluation of wave energy exploitation in a semi-enclosed sea(Elsevier, 2021-01-01) San, Murat; Akpınar, Adem; Bingölbalı, Bilal; Kankal, Murat; KANKAL, MURAT; 0000-0003-0897-4742; AAZ-6851-2020The present study aims to determine priority areas for installation of wave energy converters (WECs) in a semi-enclosed sea using a multi-criteria, spatial, decision-making analysis based on geographical information systems (GIS). The study also suggests a new methodology for determination of suitable areas for WECs taking into consideration different extreme wave conditions, intra-annual variation of wave conditions, and operational range of wave conditions by the WECs. A case study over a distance of 1140 km along the coast in the southwest Black Sea is presented. In the multi- criteria analysis, areas with environmental, economic, technical and social constraints are excluded. Ocean depth, distance to ports, shore, power line, and sub-station, wave climate, and sea-floor geology are all evaluated for their impact on the system implementation and weighted according to their relevance. Thus, the final suitability index (SI) map is produced and spatial statistical significance of the suitable areas is checked using hotspot analysis. Based on this, Kirklareli coastal area and the area between Igneada Cape and Kiyikoy village are determined as primary priority areas. The sustainability parameters with different weights proposed in this study do not differentiate priority areas but affect the SI scores. (C) 2020 Elsevier Ltd. All rights reserved.Publication Investigation of the effect of building-based assessment on flood hazard evaluation(Hard, 2022-01-01) Kurt, Zeynep O.; Yüksek, Ömer; Kankal, Murat; KANKAL, MURAT; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0003-0897-4742; AAZ-6851-2020The aim of this study is to investigate the effect of building-based assessment on flood hazards. Degirmendere, which is one of the most important basins of the Eastern Black Sea Region of Turkey, was selected as the study area. Flood hazards for discharge values with different return periods of this region were found using; the damage percentages table recommended by the Huntington Civil Engineers Association (HCEA), the Van Eck and Kok depth-loss curves, and the equation obtained by Pistrika and Jonkman. The calculations were performed both for building-based and for the region-based and compared. Furthermore, the damage rates obtained for each building on a building-based were graded and shown on the map. It was determined that the damage on individual building-based estimation for Q1,000 calculated more than to the one on region-based 154% and 17% for the damage percentages table recommended by the HCEA, Van Eck and Kok depth-loss curves, respectively. Otherwise, it gave 11% less damage estimation for the equation obtained by Pistrika and Jonkman. Furthermore, it was concluded that the increase in damage from Q(50) to Q(100), from Q(100) to Q(500) , and from Q(500) to Q(1.000) was between 16%-30% according to building-based damage estimation.Publication Wave power trends over the mediterranean sea based on innovative methods and 60-year ERA5 reanalysis(Mdpi, 2023-05-22) Acar, Emine; Akpınar, Adem; Kankal, Murat; Amarouche, Khalid; Acar, Emine; AKPINAR, ADEM; KANKAL, MURAT; AMAROUCHE, KHALID; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0002-9042-6851; 0000-0003-0897-4742; 0000-0001-7983-4611; AAZ-6851-2020; AAC-6763-2019; ABG-2101-2020; JTU-9268-2023; AFR-7886-2022The present study aims to evaluate long-term wave power (P-wave) trends over the Mediterranean Sea using innovative and classical trend analysis techniques, considering the annual and seasonal means. For this purpose, the data were selected for the ERA5 reanalysis with 0.5 degrees x 0.5 degrees spatial resolution and 1 h temporal resolution during 60 years between 1962 and 2021. Spatial assessment of the annual and seasonal trends was first performed using the innovative trend analysis (ITA) and Mann-Kendall (MK) test. To obtain more detailed information, innovative polygon trend analysis (IPTA), improved visualization of innovative trend analysis (IV-ITA), and star graph methods were applied to annual, seasonal, and monthly mean Pwave at 12 stations selected. The results allow us to identify an increasing trend above the 10% change rate with the innovative method and above the 95% confidence level with the Mann-Kendall test in mean wave power in the Levantine basin and the Libyan Sea at all timescales. The use of various innovative methods offered similar results in certain respects and complemented each other.Publication Trend analysis of maximum rainfall series of standard durations in Turkey with innovative methods(Springer, 2023-09-11) Touhedi, Hidayatullah; Kankal, Murat; Yıldız, Mehmet Berkant; Touhedi, Hidayatullah; KANKAL, MURAT; Yıldız, Mehmet Berkant; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0003-0897-4742; 0000-0001-6134-9220; JJL-6056-2023; AAZ-6851-2020; JFH-7236-2023Information about temperature and rainfall, the main elements of the Earth's climate, is essential in determining the characteristics of world climate variations. The changes in these two parameters, which show significant variability in both spatial and temporal scales, reveal essential clues for understanding the general structure of the climate. This study aims to investigate the effect of climate change on the annual maximum (extreme) rainfall values observed in Turkey. In this context, trend analyses were performed using Mann-Kendall (MK) test, innovative trend analysis (ITA), and improved visualization of ITA (IV-ITA) methods to the standard durations (t = 5, 10, 15, 30 min, and 1, 2, 3, 4, 5, 6, 8, 12, 18, 24 h) of the annual maximum rainfalls of 82 stations located in seven geographical regions of Turkey between 1975 and 2015. Trends for low and high maximum rainfall values were determined with IV-ITA. According to the MK test, there was an increasing trend of 15% in all stations, while only a decreasing trend of 1% was detected. Besides, the ITA method determined these values as 63% and 17%, respectively. The trends for low and high category values in the IV-ITA method are consistent, with approximately 60% increasing and 20% decreasing trends. An increasing trend is dominant throughout Turkey, and this trend is concentrated in the Black Sea, Marmara, and Aegean regions. Medium- and long-duration rainfall tended to increase, while short-duration rainfall tended to decrease.Publication Suspended sediment load prediction in rivers by using heuristic regression and hybrid artificial intelligence models(Yıldız Teknik Üniversitesi, 2020-06-01) Yılmaz, Banu; Aras, Egemen; Kankal, Murat; Nacar, Sinan; KANKAL, MURAT; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0003-0897-4742; AAZ-6851-2020Accurate prediction of amount of sediment load in rivers is extremely important for river hydraulics. The solution of the problem has been become complicated since the explanation of hydraulic phenomenon between the flow and the sediment on the river is dependent many parameters. The usage of different regression methods and artificial intelligence techniques allows the development of predictions as the traditional methods do not give enough accurate results. In this study, data of the flow and suspended sediment load (SSL) obtained from Karsikoy Gauging Station, located on Coruh River in the north-eastern of Turkey, modelled with different regression methods (multiple regression, multivariate adaptive regression splines) and artificial neural network (ANN) (ANN-back propagation, ANN teaching-learning-based optimization algorithm and ANN-artificial bee colony). When the results were evaluated, it was seen that the models of ANN method were close to each other and gave better results than the regression models. It is concluded that these models of ANN method can be used successfully in estimating the SSL.Publication Analysis of the precipitation intensity values of various durations in Trabzon province of Turkey by sen's innovative trend method(Yildiz Technical Univ, 2019-03-01) Terzioğlu, Zeynep Özge; Yüksek, Ömer; Nemli, Murat Özer; KANKAL, MURAT; Akçay, Fatma; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0003-0897-4742; AAZ-6851-2020Hydrological and meteorological studies indicate that hydrological processes and water resources are significantly affected by the climate change, particularly with increasing greenhouse gases and temperature. In this study, the trend analyses of the biggest precipitation intensity values in Trabzon, the most populous province of the Eastern Black Sea Basin in Turkey, have been carried out by using Mann-Kendall and Sen's Innovative Trend methods. In line with this purpose; the precipitation intensity data of standard time series from 5 minutes to 24 hours for two meteorological stations in Trabzon (Trabzon and Akcaabat) were used. Before carrying out trend analyses, the Run (Swed Eisenhart) Homogeneity Test was applied to all data and non-homogeneous data were not analysed. Before applying the Mann-Kendall Method, the internal dependency of the data was examined. When the analysis results are reviewed; in Trabzon Meteorology Station an increasing trend for intensities of all-time series has been detected, whereas in the Akcaabat Meteorology Station, a general result of the trend could not be obtained as most the data related to different time series were not homogeneous data.