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Doç. Dr. Vahdettin DemirKTO KARATAY ÜNİVERSİTESİ/MÜHENDİSLİK VE DOĞA BİLİMLERİ FAKÜLTESİ/İNŞAAT MÜHENDİSLİĞİ BÖLÜMÜ/İNŞAAT MÜHENDİSLİĞİ PR. (TAM BURSLU)/
Taban akımı yağış miktarı azaldığında veya kurak zamanlarda yağış olmadığında nehrin kurumasını engeller ve nehirdeki akışın devamlılığını sağlar. Ayrıca taban (baz) akımı çok yağış alan ve kar erimesinin uzun süre devam ettiği drenaj alanlarında taşkınları etkilemektedir. Bu nedenle özellikle taşkın ve kuraklık çalışmalarında baz akımı dikkate alınmalıdır. Bu çalışmada baz akımı, debi-sürek eğrisi kullanılarak Samsun-Kürtün Irmağı için elde edilmiştir. Kürtün Irmağı için incelenen bu çalışmada zamanın %95’inde var olan debi taban akımı olarak alınmıştır. Kürtün Irmağı, Yeşilırmak-Kızılırmak n ...Daha fazlası
In this study, monthly solar radiation (SR) estimation was performed using five different machine learning-based approaches. The models used are support vector machine regression (SVMR), long short-term memory (LSTM), Gaussian process regression (GPR), extreme learning machines (ELM) and K-nearest neighbors (KNN). Modeling of these approaches was carried out in two stages. In the first stage, VIF analysis was carried out to develop the model. Thus, the input parameters that decrease the performance of the model are removed. In the second stage, remaining input parameters such as meteorological ...Daha fazlası
Determining water level changes in lakes is significant for sustainable water supply planning, flood control, water resource management, and economic development with ecosystem sustainability. Trend analysis is a commonly used tool for detecting changes in hydrologic time series of quantities such as lake level, precipitation and temperature. Trend analysis of meteorological variables is very important for assessing the long-term changes in lake levels. This study examines long-term changes in the lakes in the Central Anatolia region of Turkey. Kızören and Timraş sinkhole lakes and Lakes Tuz a ...Daha fazlası
Floods are considered one of the most important natural disasters after earthquakes in Turkey. As a result, there is currently great public interest in this issue and it is necessary to intensify research activities in order to understand natural disasters better and to reinforce risk management. The effect of climate change on meteorological events causes an increase in extreme events such as excessive precipitation in some regions. An extreme natural event becomes a disaster when it has a large impact on human settlements and activities. Study area Samsun city is placed in the north of Turke ...Daha fazlası
Soft computing models are known as an efficient tool for modelling temporal and spatial variation of surface water quality variables and particularly in rivers. These model’s performance relies on how effective their simulation processes are accomplished. Fuzzy logic approach is one of the authoritative intelligent model in solving complex problems that deal with uncertainty and vagueness data. River water quality nature is involved with high stochasticity and redundancy due to the its correlation with several hydrological and environmental aspects. Yet, the fuzzy logic theory can give robust ...Daha fazlası
This study aims to investigate the trend of water-level changes in lakes (Lake Tuz and Lake Beyşehir) and sinkholes (Timraş and Kızören) in the Konya Closed Basin located in Turkey. Water-level changes in these lakes and sinkholes were investigated along with changes in meteorological parameters (precipitation, temperature, and evaporation) and groundwater trends that indicate the climate in the region. Several statistical tests can be used to determine the signifcance of hydrological trends over time. These tests are divided into two categories: parametric and nonparametric. In this study, th ...Daha fazlası
YAĞBASAN, Özlem | DEMİR, Vahdettin | YAZICIGİL, Hasan
Trend analyses of meteorological variables play an important role in assessing the long-term changes in water levels for sustainable management of shallow lakes that are extremely vulnerable to climatic variations. Lake Mogan and Lake Eymir are shallow lakes offering aesthetic, recreational, and ecological resources. Trend analyses of monthly water levels and meteorological variables affecting lake levels were done by the Mann-Kendall (MK), Modified Mann-Kendall (MMK), Sen Trend (ST), and Linear trend (LT) methods. Trend analyses of monthly lake levels for both lakes revealed an increasing tre ...Daha fazlası
Bu çalışmada, Samsun Mert Irmağı Havzası’nda, hâlihazır haritalardan temin edilmiş yatay ve düşey koordinat bilgilerinin yer aldığı noktalardan yükseklik değerleri, M5 model ağacı (M5-tree) ve çok değişkenli uyarlamalı regresyon eğrileri (MARS) sezgisel regresyon yöntemleri kullanılarak tahmin edilmeye çalışılmıştır. Sonuçlar Tek ve Çok Değişkenli Regresyon (TDR-ÇDR) yöntemiyle karşılaştırılmıştır. Çalışmada 3 farklı giriş senaryosu incelenmiştir. Bunlar: X yönündeki koordinat bilgisiyle yükseklik tahmini (i); Y yönündeki koordinat bilgisiyle yükseklik tahmini (ii); X ve Y koordinat bilgisiyle ...Daha fazlası
BEDEN, Neslihan | DEMİR, Vahdettin | ÜLKE KESKİN, Aslı
Study area Samsun/Atakum province is almost under threat of flooding in each year. In this region, the main reason of devastating flood is the influence of the Degirmen stream especially during March, April, and July and due to seasonal rainfall, which eventually makes the district vulnerable to flooding. In addition, the human-based constructions and the collapse of water retaining structures are among the main causes of flooding. In this study flood risks of Samsun Degirmen stream determinate by MIKE 11 and GIS. Numerical model selection for studies provides advantages in developing and chan ...Daha fazlası
This study aims to carry out regional intensity−duration−frequency (IDF) equality using the relationship with IDF obtained from point frequency analysis. Eleven empirical equations used in the literature for seven climate regions of Turkey were calibrated using particle swarm optimization (PSO) and genetic algorithm (GA) optimization techniques and the obtained results were compared. In addition, in this study, new regional IDF equations were obtained for each region utilizing MultiGene Genetic Programming (MGGP) method. Finally, Kruskal–Wallis (KW) test was applied to the IDF values obtained ...Daha fazlası
ÜLKE KESKİN, Aslı | BEDEN, Neslihan | DEMİR, Vahdettin
Climate change impacts are perceived today as being very noticeable; determination of precipitation, wind, flow, evaporation and temperature trends has become essential for water resources and engineering projects in management and planning. Nowadays there is a lot of studies have been made in progress on global and regional climate changes in literature. In this study, monthly, annual and seasonal trends in average temperature, total precipitation, and average wind speed data calculated by Mann-Kendall, linear trend and Sen’s trend tests. The gauge station is located in Samsun, which is the l ...Daha fazlası
YAĞBASAN, Özlem | YAZICIGİL, Hasan | DEMİR, Vahdettin
Variations in temperature and precipitation have direct impacts on the physical, chemical and biological characteristics of the shallow lakes. This paper examines the possible linkages between climate variables and the water levels of shallow interconnected Lakes Mogan and Eymir, located 20 km south of Ankara in Central Anatolia. The variations in the lakes' water levels during 1996-2015 are studied and the impacts of climate variables on the lake levels are assessed to address the long-term consequences. The nonparametric Mann-Kendall test was used to quantify trends in the climate variables ...Daha fazlası
6698 sayılı Kişisel Verilerin Korunması Kanunu kapsamında yükümlülüklerimiz ve cerez politikamız hakkında bilgi sahibi olmak için alttaki bağlantıyı kullanabilirsiniz.