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141.
The city of Burdur, which is built on an alluvium aquifer, is located in one of the most seismically active zones in southwestern
Turkey. The soil properties in the study site are characterized by unconsolidated and water-saturated sediments including
silty, clayey and sandy units, and shallow groundwater level is the other characteristic of the site. Thus, the city is under
soil liquefaction risk during a large earthquake. A resistivity survey including 189 vertical electrical sounding (VES) measurements
was carried out in 2000 as part of a multi-disciplinary project aiming to investigate settlement properties in Burdur city
and its vicinity. In the present study, the VES data acquired by using a Schlumberger array were re-processed with 1D and
2D inversion techniques to determine liquefaction potential in the study site. The results of some 1D interpretations were
compared to the data from several wells drilled during the project. Also, the groundwater level map that was previously obtained
by hydrological studies was extended toward north by using the resistivity data. 2D least-squares inversions were performed
along nine VES profiles. This provided very useful information on vertical and horizontal extends of geologic units and water
content in the subsurface. The study area is characterized by low resistivity distribution (<150 Ωm) originating from high
fluid content in the subsurface. Lower resistivity (3–30 Ωm) is associated with the Quaternary and the Tertiary lacustrine
sediments while relatively high resistivity (40–150 Ωm) is related to the Quaternary alluvial cone deposits. This study has
also shown that the resistivity measurements are useful in the estimation of liquefaction risk in a site by providing information
on the groundwater level and the fluid content in the subsurface. Based on this, we obtained a liquefaction hazard map for
the study area. The liquefaction potential was classified by considering the resistivity distributions from 2D inversion of
the VES profiles, the types of the sediments and the extended groundwater level map. According to this map, the study area
was characterized by high liquefaction hazard risk. 相似文献
142.
Modelling palaeoglaciers in mountainous terrain is challenging due to the need for detailed ice flow computations in relatively narrow and steep valleys, high-resolution climate estimations, knowledge of pre-ice topography, and proxy-based palaeoclimate forcing. The Parallel Ice Sheet Model (PISM), a numerical model that approximates glacier sliding and deformation to simulate large ice sheets such as Greenland and Antarctica, was recently adapted to alpine environments. In an attempt to reconstruct the climate conditions during the Last Glacial Maximum (LGM) on Mount Dedegöl in SW Turkey, we used PISM and explored palaeoglacier dynamics at high spatial resolution (100 m) in a relatively small domain (225 km2). Palaeoice-flow fields were modelled as a function of present temperature and precipitation. Nine different palaeoclimate simulations were run to reach the steady-state glacier extents and the modelled glacial areas were compared with the field-based and chronologically well-established ice extents. Although our results provide a non-unique solution, best-fit scenarios indicate that the LGM climate on Mount Dedegöl was between 9.2 and 10.6 °C colder than today, while precipitation levels were the same as today. More humid (20% wetter) or arid (20% drier) conditions than today bring the palaeotemperature estimates to 7.7–8.8 or 11.5–13.2 °C lower than present, respectively. 相似文献
143.
The standard practice for assessing aquifer parameters is to match groundwater drawdown data obtained during pumping tests against theoretical well function curves specific to the aquifer system being tested. The shape of the curve derived from the logarithmic time derivative of the drawdown data is also very frequently used as a diagnostic tool to identify the aquifer system in which the pumping test is being conducted. The present study investigates the incremental area method (IAM) to serve as an alternative diagnostic tool for the aquifer system identification as well as a supplement to the aquifer parameter estimation procedure. The IAM based diagnostic curves for ideal confined, leaky, bounded and unconfined aquifers have been derived as part of this study, and individual features of the plots have been identified. These features were noted to be unique to each aquifer setting, which could be used for rapid evaluation of the aquifer system. The effectiveness of the IAM methodology was investigated by analyzing field data for various aquifer settings including leaky, unconfined, bounded and heterogeneous conditions. The results showed that the proposed approach is a viable method for use as a diagnostic tool to identify the aquifer system characteristics as well as to support the estimation of the hydraulic parameters obtained from standard curve matching procedures. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
144.
Aquifer parameter estimation using an incremental area method 总被引:2,自引:0,他引:2
Theoretical well functions have been derived over the years to predict ground water level behaviour in aquifer systems under stress owing to groundwater extraction. The drawdown data collected during pump tests are typically analysed using graphical curve‐matching procedures to estimate aquifer parameters based on these well functions. Difficulty in aquifer characteristic identification and parameter estimation may arise when the field data do not perfectly match the drawdown curves obtained from the well functions. The present study provides a new method for the interpretation of aquifer pump tests which supplements the existing curve‐matching procedures in case ideal conditions do not exist; the proposed method provides a greater degree of flexibility in the data analysis for diagnostic tool purposes. The method, referred to as the Incremental Area Method (IAM) is based on integrating the logarithmic‐based drawdown curves within a discrete time and matching the results with a corresponding time integral of the Theis ( 1935 ) Well Function which governs ideal confined aquifers. The application of the proposed method to synthetically generated data and field data showed that IAM represents a viable method which yields information on potential non‐idealness of the aquifer and provides aquifer parameter estimates thus potentially overcoming drawdown data curve‐matching difficulties. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
145.
Levent Şaylan Barış Çaldağ Fatih Bakanoğulları Hüseyin Toros Mustafa Yazgan Orhan Şen Yunus Özkoca 《洁净——土壤、空气、水》2011,39(5):491-501
Pollutants affect not only the environment in which they originate since they are also transported by air currents to other locations. For this reason, air pollution is a global problem for all countries and the air and water quality need to be monitored carefully. More information on precipitation chemistry is required to determine the source of pollution as well as its effects on the ecosystems. In this study, precipitation chemistry has been analyzed for the first time by using simple bulk collectors located at four different sites in Northwest Turkey for a period of two years. About 650 sequential rainwater samples were collected and analyzed for pH, electrical conductivity, anions such as , , Cl?, and cations such as Na+, K+, Mg2+, Ca2+, and . The selected sites were under the effect of different environmental factors. Our results showed that the highest and concentrations were measured in the Northwest of the research area. Additionally, it has been found that Ca2+ ions are abundant within all rainwater samples. 相似文献
146.
Mualla Cengiz Çinku 《International Journal of Earth Sciences》2011,100(7):1633-1645
The Jurassic paleogeographic position of the Pontides is not well studied because of insufficient paleomagnetic data. For
this reason, a paleomagnetic study was carried out in order to constrain the paleolatitudinal drift of the Turkish blocks
during the Jurassic period. A total of 32 sites were sampled from volcanic and volcanoclastic rocks of the Lower/Middle Jurassic
Kelkit formation (Eastern Pontides), Mudurnu formation (Sakarya continent) and Upper Jurassic–Lower Cretaceous Ferhatkaya
formation exposed around Amasya region (Eastern Pontides). Rock magnetic experiments demonstrate that the main ferromagnetic
mineral is pseudo-single-domain titanomagnetite in these rocks. Paleomagnetic analysis revealed two main components of the
natural remanent magnetization during stepwise thermal and alternating field demagnetization. The first component is a low-coercivity
(unblocking temperature) component with a direction sometimes similar to that of the earth’s present field or a viscous component.
The second component, which is interpreted as the characteristic remanent magnetization (ChRM) direction, has low to high
coercivity properties between 20 and 100 mT or unblocking temperatures between 300 and 580°C. A positive fold test at the
95% level of confidence proved that the ChRM of the sites is primary. Paleomagnetic directions calculated for the Kelkit formation
in the Eastern Pontides have a mean direction of D = 334.8°, I = 49.7°, α
95 = 7.1° after tilt-correction. A mean direction of D = 332.2°, I = 48.5°, α
95 = 14.6° was obtained from the volcanoclastic rocks of the Mudurnu formation, and D = 324.3°, I = 43.3°, α
95 = 9.5° was calculated for the Upper Jurassic–Lower Cretaceous limestones/Ferhatkaya formation of the Amasya region. The Jurassic
rocks in the Eastern Pontides and Mudurnu region are considered to represent products of the rifted Neo-Tethys ocean, while
the Upper Jurassic–Lower Cretaceous sediments in Amasya are related to basin-filling materials. The data suggest that the
Kelkit formation was formed at 30.5°N paleolatitude and the equivalent Mudurnu formation at 29.5°N paleolatitude. The paleolatitude
of the Eastern Pontides indicates that this rifting block was separated from Eurasia by a marginal basin instead of being
a part of Eurasia. The lower paleolatitude of the Amasya region at 24.8°N in the Upper Jurassic to Lower Cretaceous clearly
indicates southward drift of the Turkish blocks during the Jurassic to Lower Cretaceous period together with the motion of
Eurasia. 相似文献
147.
Erkan Çelebi Muharrem Aktas Naci Çağlar Aşkın Özocak Mustafa Kutanis Necati Mert Zeki Özcan 《Natural Hazards》2013,65(3):2287-2310
On October 23, 2011, a magnitude of Mw 7.2 earthquake struck the Van province in eastern Turkey which caused approximately 600 life loss and 4,000 injured people. Although the recorded peak ground accelerations were relatively low (0.15–0.2 g) compared with that of other recent destructive Turkish earthquakes and the code-based design response spectrum, a large number of reinforced concrete buildings with 4–6 stories and non-engineered masonry buildings were either heavily damaged or collapsed in the region. Based on the post-earthquake technical inspections, the goal of this paper is to introduce major reasons for structural damages in the disaster area and to discuss these failures along with the approaches given in the design code which is renewed after August 17, 1999 Marmara Earthquake. Some remarkable lessons learned from earthquake-induced failures and damages specific to building construction techniques are presented in this paper. 相似文献
148.
The homogeneity of newly compiled 212 precipitation records in Turkey for the period 1973‐2002 was checked by the Standard Normal Homogeneity Test (SNHT) and Pettitt Test. Stations were considered inhomogeneous if at least one of the tests rejects the homogeneity. As a result, 43 out of 212 stations were found to be inhomogeneous. In addition, the previously detected Southern Oscillation (SO)‐related precipitation anomalies by the authors were quantified at each station using the gamma distribution. The observed SO‐related shifts in the median precipitation amounts expressed as gamma percentiles may be considered as a typical SO response of that station. The results of this study confirm the wet responses of Turkish precipitations to El Nino events, whereas those for La Nina events seem to be masked by sampling variations within the study period. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
149.
150.
Natural Hazards - In this paper, the seismic behavior of the existing reinforced concrete tall building is investigated by using the linear and nonlinear dynamic methods. The selected existing... 相似文献