Yazar "Kurtulus, Bedri" seçeneğine göre listele

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    A NEW ARTIFICIAL NEURAL NETWORK MODEL FOR THE PREDICTION OF THE RAINFALL-RUNOFF RELATIONSHIP FOR LA CHARTREUX SPRING, FRANCE
    (Parlar Scientific Publications (P S P), 2018) Inan, Cagri Alperen; Canoglu, Mustafa Can; Kurtulus, Bedri
    The prediction of a rainfall-runoff relationship includes complex processes in karstic aquifer systems. In this study, an artificial neural network (ANN) model is utilized in order to simulate the rainfall -runoff relationships of La Chartreux spring in the karstic region Cahors, Southern France. Since numerical models are thought to be insufficient, the present study will contribute to the improvement of rainfall-discharge prediction models by using ANNs in MATLAB software. The model has been conducted with a feed forward and back propagation algorithm. The model is improved by the Levenberg-Marquardt algorithm in order to generalize the complex and non-linear rainfall-runoff issues. The meteorological data was obtained from meteorological stations in the region including eight years of rainfall and discharge data between 1976 and 1983. Model performance has been evaluated with respect to statistical error measures (root mean square error (RMSE), and correlation coefficient square (R-2). This study confirmed that artificial neural networks are capable of predicting rainfall-runoff relationships depending on the data quality, neural network properties, and data variability.
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    ASSESSMENT OF HEAVY METAL CONTAMINATION AND ACCUMULATION PATTERNS IN THE COASTAL AND DEEP SEDIMENTS OF LAKE SALDA, TURKEY
    (Parlar Scientific Publications (P S P), 2017) Caldirak, Huseyin; Kurtulus, Bedri; Canoglu, Mustafa Can; Tunca, Evren
    In this study, contamination levels were found for 8 different metals (Cu, Pb, Zn, Ni, Mn, Fe, Cd, Cr) and metalloids (As) in sediment samples, coming from 9 different stations, through statistical analysis and sediment assessment at Lake Salda (Turkey). The correlation, cluster, factor and Mann Whitney-U analysis were used for evaluation of the results, and the values of all metals were compared with the limit values of PEL (probable effect level), ERM (effect range median), TEL (threshold effect level), and ERL (effect range low). According to the correlation, PCA and cluster analysis, highest correlation was determined as being between Cu-Mn, Cu-Zn, Fe-Ni, Cr-Ni and Fe-Cr. The weakest relationships with other metals were identified as Pb and As. Additionally, deep and shallow stations were compared and station-based anthropogenic effects were demonstrated. The status of the sediments was considered separately for the studied elements. According to the results, contamination factor, enrichment factor, geoaccumulation index, potential ecological risk factor and quotient toxic unit showed up the highest values for Ni. However, Pb results seemed quite serious at several stations according to the results of the research. The pollution load index was used to find out the baseline and ideal levels throughout the lake.
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    Elemental accumulation in the surficial sediment of Kesikkopru, cubuk II and Asartepe Dam Lakes (Ankara) and potential sediment toxicity
    (Taylor & Francis Ltd, 2021) Fikirdesici-Ergen, Seyda; Tekatli, Cagri; Gurbuzer, Pinar; ucuncu-Tunca, Esra; Ture, Hasan; Biltekin, Demet; Kurtulus, Bedri
    In this study, cubuk 2, Kesikkopru and Asartepe Dam Lake, were investigated. A total of 60 sediment samples were collected and the concentrations of 10 elements (Cu, Pb, Zn, Ni, Mn, Fe, Co, Cr, Al, As) were determined. The obtained findings were compared to the limit values for the sediment quality guidelines (SQGs) and were investigated using sediment assessment methods. The results indicate that the values for SQGs revealed that the concentrations of Ni and As should be emphasised. Toxic unit (TU) values showed that As and Ni together constitute 69.95-80.09% of the total toxic effect alone for all lakes. In addition, the Contamination factor (Cf) and Enrichment factor (EF) detected the concentration of As for Kesikkopru Dam Lake as being at a medium and higher accumulation levels, although the Geoaccumulation index (Igeo) detected that As leads to contamination below the medium level. When the total element accumulation was evaluated, no risk was detected for the lakes. Cluster analysis (CA) revealed quite different elemental profiles for 3 lakes. The strongest correlation between the elements was observed for Cu-Ni (r = 0.942) in cubuk 2, whereas cubuk 2 was the lake with the highest seasonal elemental variation among the lakes investigated.
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    Investigating the Structure of a Coastal Karstic Aquifer through the Hydrogeological Characterization of Springs Using Geophysical Methods and Field Investigation, Gokova Bay, SW Turkey
    (Mdpi, 2020) Sagir, Cagdas; Kurtulus, Bedri; Soupios, Pantelis; Ayranci, Korhan; Duztas, Erkan; Aksoy, Murat Ersen; Avsar, Ozgur
    The electrical resistivity tomography method has been widely used in geophysics for many purposes such as determining geological structures, water movement, saltwater intrusion, and tectonic regime modeling. Karstic springs are important for water basin management since the karst systems are highly complex and vulnerable to exploitation and contamination. An accurate geophysical model of the subsurface is needed to reveal the spring structure. In this study, several karst springs in the Gokova Bay (SW, Turkey) were investigated to create a 3D subsurface model of the nearby karstic cavities utilizing electrical resistivity measurements. For this approach, 2D resistivity profiles were acquired and interpreted. Stratigraphically, colluvium, conglomerate, and dolomitic-limestone units were located in the field. The resistivity values of these formations were determined considering both the literature and field survey. Then, 2D profiles were interpolated to create a 3D resistivity model of the study area. Medium-large sized cavities were identified as well as their locations relative to the springs. The measured resistivities were also correlated with the corresponding geological units. The results were then used to construct a 3D model that aids to reveal the cavity geometry in the subsurface. Additionally, several faults are detected and their effect on the cavities is interpreted.
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    Land subsidence assessment under excessive groundwater pumping using ESA Sentinel-1 satellite data: a case study of Konya Basin, Turkey
    (Springer, 2021) Yesilmaden, Hande Mahide; Inan, Cagri Alperen; Kurtulus, Bedri; Canoglu, Mustafa Can; Avsar, Ozgur; Razack, Moumtaz
    Land subsidence analysis using satellite imagery is a consequential subject. Earth scientists have begun utilizing satellite imagery as an alternative to in-situ measurements and conceptual models. Synthetic aperture radar (SAR) images, moreover, utilize the reformer approach more than traditional satellite imagery with the use of high-resolution radar images. As a natural hazard, land subsidence is mostly attributed to excessive groundwater extraction, which is also the main reason for choosing the Konya Plain in Turkey as the study area for the present work. Since the Konya region is an agricultural and industrial land, groundwater extraction has been a challenging circumstance for the last few years. Change in groundwater level is also correlated with land subsidence rates through hydrogeological conceptualization. In this study, SAR images of the Sentinel 1 satellite are utilized for land subsidence rate calculation with the European Space Agency's SNAP software. Differential SAR interferometry (DInSAR) technique was used, which makes possible to detect deformation on the ground surface of the same portion of the Earth's surface using SAR images. The different acquisitions with DInSAR method allow to create differential interferograms that provide information ground motion with accuracy in cm. Three periods were utilized as 2016-2017, 2017-2018 and 2018-2019 the mean land subsidence rates were calculated for each period as 2.2, 1.4 and 1.7 cm/year, respectively. In the sum of the 3-year period, the maximum subsidence value went up to 16 cm.
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    SOIL-AQUIFER INTERACTIONS AND VADOSE ZONE MODELING: AN EXAMPLE FROM MARAIS POITEVIN (WESTERN FRANCE)
    (Carpathian Assoc Environment And Earth Sciences, 2019) Canoglu, Mustafa Can; Kurtulus, Bedri; Razack, Moumtaz
    Water flux in unsaturated zone is one of the most important phenomenon for determining the recharge characteristics of an aquifer. In-situ measurement and simulation models have been developed in recent years to characterize the recharge process in unsaturated zone. Recently, a mechanistic model named as AgriFlux have been adopted to specify the water fluxes in unsaturated zone. In this study, water flows in the unsaturated zone is investigated in order to understand a global interaction of soil-aquifer exchange system and to simulate the water flux leaching from unsaturated zone of soil and capacitance using AgriFlux model. Input parameters of the model were characterized by in-situ measurement and laboratory works. In-situ measurement were done by auger hole and Porchet test at 36 locations. Within laboratory tests, mineralogy of soil samples is characterized by X ray diffraction (XRD) and grain size distribution is determined on the undisturbed soil sampled from study area. The modelling results reveal that a percolated total water flow leaching through the unsaturated zone. The results were also compared with the observed ground water level fluctuations in the aquifer. Consequently, water flow quantification of a soil - aquifer system in Poitevin Marshland signpost the recharge characteristics of Bri Aquifer.
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    SPATIAL AND TEMPORAL ASSESSMENT OF METAL(LOID) CONTAMINATION IN ASARTEPE DAM LAKE (ANKARA, TURKEY) USING POLLUTION INDICES AND MULTIVARIATE STATISTICAL ANALYSIS
    (Parlar Scientific Publications (P S P), 2019) Kurtulus, Bedri; Sagir, Cagdas; Erdem, Gunseli; Tunc, Semih Okan; Canoglu, Mustafa Can; Tunca, Evren
    This study has investigated metal(loid) contamination in Asartepe Dam Lake, which is used for irrigation in Ankara, Turkey. Contamination Factor and Degree of Contamination were applied to evaluate contamination in the lake sediment. The contamination was shown to be moderate according to a modified Degree of Contamination analysis. Chromium was found to be the highest calculated metal on the Geoaccumulation Index, and the lake was found to be moderate-to-strongly contaminated according to the same method. The Pollution Load Index for the lake sediment varied between 3.11 and 3.5. Enrichment Factors suggest a minor anthropogenic origin for metal(loid) pollution; various statistical techniques were implemented. The greatest correlation among water-borne metal(loid)s was shown by analysis to be between iron and titanium. No strong correlation was observed for sediment samples. The results show that the lake water is relatively free of metal(loid)s. However, this is not the case for the lake sediment.
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    Su Yapilarinda Gövde Tipi Optimizasyonu ve Dogal Yapi Malzemelerinin Mühendislik Parametrelerinin Belirlenmesi: Kislademirli Göleti Örnegi Kütahya
    (Zonguldak Bülent Ecevit Üniversitesi, 2016) Canoglu, Mustafa Can; Kurtulus, Bedri
    Bu çalisma, Kütahya ili, Tavsanli Ilçesi, Kislademirli Göleti için gerekli dogal yapi malzemelerinin mühendislik özelliklerinin arastirilmasi, gölet gövde tipine karar verilmesini kapsamaktadir. Bu baglamda, büro, arazi ve laboratuvar çalismalari gerçeklestirilmistir. Sahanin genel jeolojisi, gövdede kullanilabilecek potansiyel geçirimli, geçirimsiz ve kaya malzeme alanlari 1/25.000’lik harita üzerinden büro çalismalari ile belirlenmistir. Arazi çalismalari kapsaminda ise malzeme alanlarinin kullanilabilirligi ve potansiyel malzeme miktarlari gözlemsel olarak ortaya koyulmustur. Daha sonra geçirimli ve geçirimsiz malzeme alanlarinda arastirma çukurlari açilmis ve ilgili malzeme alanindaki kullanilabilir derinlik yine gözlemsel olarak belirlenmistir. Bunun sonucunda, Kislademirli Göleti dogal yapi malzemesi ihtiyaçlarinin belirlenmesi amaci ile 2 adet geçirimsiz malzeme alaninda toplam 18 adet arastirma çukuru, 2 adet geçirimli malzeme alaninda toplam 11 adet arastirma çukuru olmak üzere toplamda 29 adet malzeme arastirma çukuru açilmistir. Sahada açilan arastirma çukurlarindan ve 1 adet kaya malzeme alanindan alinan temsil edici numuneler ise laboratuvar testlerine tabi tutulmus ve ilgili malzeme alaninin kullanilabilir olup olmadigi ortaya koyulmustur. Buna bagli olarak, kullanilabilir dogal yapi malzemelerinin, gölet aksina olan uzakligi, malzeme miktari ve niteligi göz önüne alinarak, gölet gövde tipine karar verilmistir