排序方式： 共有46条查询结果，搜索用时 156 毫秒
11.
Tolga Yalcin 《Aquatic Geochemistry》2007,13(1):75-93
Thermal water chemistry from the Biga Peninsula (NW Turkey) was investigated in order to discriminate among hydrochemical
facies, and isotopic groups and identify the major geochemical processes. A systematic hydrogeochemical survey was carried
out, incorporating new data as well as results from the previous studies. Results were used to further develop hydrogeological
and geochemical models. Thermal water compositions were classified into four groups and the processes affecting evolution
of water compositions were interpreted. Types 1, 2 and 3 are representatives of water corresponding to sulfate dominant fluids
(mainly NaSO4-type), chloride dominant fluids (mainly NaCl-type), and bicarbonate dominant fluids (Na- or CaHCO3-type), respectively. Group 4 comprises the fluids with compositions that are not dominated by any distinctive anion. Groundwater
infiltrates and circulates through the marbles of the Paleozoic basement. The isotopic composition of thermal waters revealed
that deep infiltration of meteoric water took place in periods of changed climatic conditions. 相似文献
12.
13.
Kivanc Zorlu M. Celal Tunusluoglu Tolga Gorum Hakan A. Nefeslioglu Ali Yalcin Dilek Turer Candan Gokceoglu 《Environmental Earth Sciences》2011,62(8):1685-1693
The Cappadocia region has unique geomorphological features resulting from differential erosional processes which make it very attractive to tourists. Besides the fairy chimneys for which the area is best known, there are also impressive buttes and mesas. Buttes and mesas are formed in regions having flat-lying strata in which the uppermost levels are composed of well-cemented limestones and granular ignimbrites, whereas the lower parts and slopes consist of low-durability tuff and ignimbrites. This durability difference results in serious rockfall events. This study involves two-dimensional rockfall analyses in and near the Avanos, Zelve, and Çavusini areas, where volcano-sedimentary units of Neogene age outcrop, to provide a rockfall hazard map in which areas of tourism activity are also considered. 相似文献
14.
We performed a probabilistic analysis of earthquake hazard input parameters, NW Turkey covers Gelibolu and Biga Peninsulas, and its vicinity based on four seismic sub-zones. The number of earthquakes with magnitude M ≥ 3.0 occurred in this region for the period between 1912 and 2007 is around 5130. Four seismic source sub-zones were defined with respect to seismotectonic framework, seismicity and fault geometry. The hazard perceptibility characterization was examined for each seismic source zone and for the whole region. The probabilities of earthquake recurrences were obtained by using Poisson statistical distribution models. In order to determine the source zones where strong and destructive earthquakes may occur, distribution maps for a, b and a/b values were calculated. The hazard scaling parameters (generally known as a and b values) in the computed magnitude–frequency relations vary in the intervals 4.28–6.58 and 0.59–1.13, respectively, with a RMS error percentage below 10 %. The lowest b value is computed for sub-zone three indicating the predominance of large earthquakes mostly at Gelibolu (Gallipoli) and north of Biga Peninsula (southern Marmara region), and the highest b value is computed for sub-zone two Edremit Bay (SW Marmara region). According to the analysis of each seismic sub-zone, the greatest risk of earthquake occurrence is determined for the triangle of Gelibolu–Tekirda? western part of Marmara Sea. Earthquake occurrence of the largest magnitude with 7.3 within a 100-year period was determined to be 46 % according to the Poisson distribution, and the estimated recurrence period of years for this region is 50 ± 12. The seismic hazard is pronounced high in the region extending in a NW–SE direction, north of Edremit Bay, west of Saros Bay and Yenice Gönen (southern Marmara region) in the south. High b values are generally calculated at depths of 5–20 km that can be expressed as low seismic energy release and evaluated as the seismogenic zone. 相似文献
15.
The Normalized Full Gradient (NFG) method has widespread applications in the analysis of potential fields, especially the gravity and magnetic fields. This method is used to identify the lateral and horizontal density variations in the crust and lithosphere. In this study, the NFG method was applied to the gravity data of the Cretan Arc and its surroundings. Because of the tectonic features of the eastern Mediterranean, the Cretan Arc and the neighboring areas are seismically very active. Especially the subduction zone and the complicated crustal features have been defined applying many different geophysical methods. In this study, first the NFG method is tested with synthetic prisms (two cubes). After that, the NFG method was applied to the Bouguer gravity data of the Cretan Arc and its subduction zone (Hellenic subduction zone) and Hellenic subduction zone was defined with the foci depth data (USGS) along the south–north direction. Thus, geometry of the focal depth distribution has been created to determine probable media depths and their localizations. According to the NFG results, vertical structural transitions were observed at a depth ranging between 10 and 180?km. Also, these results were compared with the foci depth model and the other results of the related publications. Finally, some considerations in vertical solution with the NFG method have been presented and locations of the different structures at horizontally have been defined with application of the NFG method. 相似文献
16.
The urban heat island (UHI) is a result of urbanization, causing local microclimatologic changes such as increase in ambient temperature. Factors causing the UHI effect are anthropogenic energy release, energy absorption by concrete, tarmac structures and traffic, although the main factor is the replacement of vegetation with man-made structures. These factors cause heating of not only local air but also subsurface and groundwater. Observations of groundwater temperatures from the urban, southern part of Istanbul (Turkey) and the rural, northern part of Istanbul revealed that the urban groundwater temperatures were 3.5°C higher than the rural. Urbanization is a direct consequence of improvements in technology and modern life. However, this comes at the cost of an ever-increasing demand for energy. Exploitation of low-enthalpy geothermal energy is an attractive alternative to fossil fuel based energies. From the environmental point of view, clean and cheap energy is the most preferable, with heat pumps being the best choice for recovery purposes. Usage of elevated groundwater temperature in the heat pumps in urban areas increases the efficiency of the heat pump system and yields more thermal energy than that of rural groundwater. This system may be applicable to Istanbul. 相似文献
17.
Seismic behaviour of shallow foundations: Shaking table experiments vs numerical modelling 总被引：1，自引：0，他引：1
The capability of a simplified approach to model the behaviour of shallow foundations during earthquakes is explored by numerical simulation of a series of shaking table tests performed at the Public Works Research Institute, Tsukuba, Japan. After a summary of the experimental work, the numerical model is introduced, where the whole soil–foundation system is represented by a multi‐degrees‐of‐freedom elasto‐plastic macro‐element, supporting a single degree‐of‐freedom superstructure. In spite of its simplicity and of the large intensity of the excitation involving a high degree of nonlinearity in the foundation response, the proposed approach is found to provide very satisfactory results in predicting the rocking behaviour of the system and the seismic actions transmitted to the superstructure. The agreement is further improved by introducing a simple degradation rule of the foundation stiffness parameters, suitable to capture even some minor details of the observed rocking response. On the other hand, the performance of the model is not fully satisfactory in predicting vertical settlements. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
18.
Alper Erdem Yılmaz Yeşim Dede Sağsöz Baybars Ali Fil Murat Tolga Yılmaz 《洁净——土壤、空气、水》2023,51(1):2200032
In this study, domestic wastewater was used as the electrolyte. The work was carried out with an up-flow tubular reactor, made of stainless steel that was used as cathode, while the anode electrode material was aluminum and varying values of flow regime (25, 50, 75 and 100 mL/s for continuous system), initial pH value (5, 6, 7 and 7.8) and current intensity (10, 15 and 20 A) were applied. For domestic wastewater with natural pH, the effluent pH was >9 in the batch system, while in the continuous system the pH was 8–8.5. Likewise, while the effluent temperature was up to 60°C in the batch system, it was at most 35°C in the continuous system. However, the energy consumption values in the continuous system were considerably lower compared with the batch system. At a current intensity of 10 A, 80 kWh of energy per unit volume was consumed in the batch system, while it was 50 kWh for the continuous system. The present results show that the batch system can be used for small wastewater streams whereas the continuous system can be used for large wastewater streams for domestic wastewater treatment. 相似文献
19.
Erkan Gökaşan Hüseyin Tur Berkan Ecevitoğlu Tolga Görüm Ahmet Türker Buğser Tok Faruk Çağlak Halim Birkan Mehmet Şimşek 《Geo-Marine Letters》2005,25(5):324-342
The Strait of İstanbul (SoI) (Bosphorus) is a narrow valley, which has evolved tectonically from a stream, and in which thick
sediment deposits have accumulated in the course of its evolution. Detailed seismic and multi-beam bathymetric data have revealed
that the upper parts of the deeper channel deposits consist of parallel strata, which have mostly been eroded subsequently
to their deposition. The resulting erosion surface is represented by the present channel floor in the strait, the estimated
volume of the eroded material being approximately 2×108 m3 . Erosion rate and seafloor morphology indicate that the flow direction was from the south to the north. This inner channel
may have been formed by an abrupt flooding of the Black Sea by Mediterranean waters at the beginning of the latest connection
between the Marmara and the Black seas. Subsequently, the Mediterranean bottom current of the modern two-way flow system,
which was established at about 5–4 ka b.p., has given the latest shape to the strait floor. 相似文献
20.
Fusun Balik Sanli Saygin Abdikan Mustafa Tolga Esetlili Filiz Sunar 《Journal of the Indian Society of Remote Sensing》2017,45(4):591-601
This research aimed to explore the fusion of multispectral optical SPOT data with microwave L-band ALOS PALSAR and C-band RADARSAT-1 data for a detailed land use/cover mapping to find out the individual contributions of different wavelengths. Many fusion approaches have been implemented and analyzed for various applications using different remote sensing images. However, the fusion methods have conflict in the context of land use/cover (LULC) mapping using optical and synthetic aperture radar (SAR) images together. In this research two SAR images ALOS PALSAR and RADARSAT-1 were fused with SPOT data. Although, both SAR data were gathered in same polarization, and had same ground resolution, they differ in wavelengths. As different data fusion methods, intensity hue saturation (IHS), principal component analysis, discrete wavelet transformation, high pass frequency (HPF), and Ehlers, were performed and compared. For the quality analyses, visual interpretation was applied as a qualitative analysis, and spectral quality metrics of the fused images, such as correlation coefficient (CC) and universal image quality index (UIQI) were applied as a quantitative analysis. Furthermore, multispectral SPOT image and SAR fused images were classified with Maximum Likelihood Classification (MLC) method for the evaluation of their efficiencies. Ehlers gave the best score in the quality analysis and for the accuracy of LULC on LULC mapping of PALSAR and RADARSAT images. The results showed that the HPF method is in the second place with an increased thematic mapping accuracy. IHS had the worse results in all analyses. Overall, it is indicated that Ehlers method is a powerful technique to improve the LULC classification. 相似文献