排序方式： 共有23条查询结果，搜索用时 15 毫秒
11.
The purpose of this study is to assess the susceptibility of landslides around Yomra and Arsin towns near Trabzon, in northeast
of Turkey, using a geographical information system (GIS). Landslide inventory of the area was made by detailed field surveys
and the analyses of the topographical map. The landslide triggering factors are considered to be slope angle, slope aspect,
distance from drainage, distance from roads and the weathered lithological units, which were called as “geotechnical units”
in the study. Idrisi and ArcGIS packages manipulated all the collected data. Logistic regression (LR) and weighted linear
combination (WLC) statistical methods were used to create a landslide susceptibility map for the study area. The results were
assessed within the scope of two different points: (a) effectiveness of the methods used and (b) effectiveness of the environmental
casual parameters influencing the landslides. The results showed that the WLC model is more suitable than the LR model. Regarding
the casual parameters, geotechnical units and slopes were found to be the most important variables for estimating the landslide
susceptibility in the study area. 相似文献
12.
Magnitude conversion problem for the Turkish earthquake data 总被引：1，自引：0，他引：1
Earthquake catalogues which form the main input in seismic hazard analysis generally report earthquake magnitudes in different
scales. Magnitudes reported in different scales have to be converted to a common scale while compiling a seismic data base
to be utilized in seismic hazard analysis. This study aims at developing empirical relationships to convert earthquake magnitudes
reported in different scales, namely, surface wave magnitude, M
S, local magnitude, M
L, body wave magnitude, m
b and duration magnitude, M
d, to the moment magnitude (M
w). For this purpose, an earthquake data catalogue is compiled from domestic and international data bases for the earthquakes
occurred in Turkey. The earthquake reporting differences of various data sources are assessed. Conversion relationships are
established between the same earthquake magnitude scale of different data sources and different earthquake magnitude scales.
Appropriate statistical methods are employed iteratively, considering the random errors both in the independent and dependent
variables. The results are found to be sensitive to the choice of the analysis methods. 相似文献
13.
A large and rapid planar failure: causes,mechanism, and consequences (Mordut,Gumushane, Turkey) 总被引：3，自引：0，他引：3
Gumushane is a small city located on highway connecting the harbour city Trabzon in the Black Sea Region of Turkey to the Eastern Anatolia. Following an excavation to create an area for housing on the northeast side of this highway, a large and rapid planar failure inclined to the southwest occurred. A large amount of fractured and weathered granitic material moved downward over this planar failure. After the failure, the highway was closed to traffic for 1 week, and more than ten houses on top of this failure were collapsed completely. The present study aims to investigate the mechanism of this failure. The study was performed using kinematical, limit equilibrium and numerical analyses for both post- and pre-failure conditions. Based on the detailed field observations, the failure mode was determined to be planar, and the slide mechanism was determined to be controlled by three fault planes. As a result of these analyses, it can be concluded that the slope before failure had critical conditions and that the excavation and uncontrolled blasting triggered and accelerated the slope failure. 相似文献
14.
Thomas Rockwell Aykut Barka Timothy Dawson Serdar Akyuz Kim Thorup 《Journal of Seismology》2001,5(3):433-448
We excavated five trenches across the North Anatolia fault zone (NAFZ)along the Ganos fault (Gazikoy-Saros segment), which last produced surfacerupture in 1912, near Kavakkoy where the fault enters the Gulf of Saros. The trenches exposed faulted sediments in a flood-plain environment withabundant detrital charcoal and scattered land-snail shells. Twenty-tworadiocarbon dates place constraints on the ages of the exposed sediments,which range from less than a few hundred years to about 6000 years inage. In two closely spaced trenches, we identified five discrete earthquakeevent horizons in the upper 2.5 m of stratigraphy based on abruptupward termination of shear zones, folding, fissuring, and abruptstratigraphic thickening, four of which may corresponded to historicallyrecorded large regional earthquakes. The earliest of the identified eventsoccurs below an unconformity and dates to about 4 ka B.P. The morerecent four events all occurred within the past 1000–1200 years and maycorrespond to large earthquakes in A.D. 824, ca 1354, 1509, 1766 and1912 (Ambraseys and Finkel, 1987, 1991, 1995). In another trench,we identified at least two events that have occurred during the past 500years and probably correspond to the large events of 1766 and 1912. These observations support an average return period of about 250–300years for the Gazikoy-Saros segment of the NAFZ. They also suggest thatthis segment, which is bound both to the east and west by large releasingstepovers, behaves in a quasi-periodic fashion, at least for the past severalsurface ruptures.Most of the 23 mm/yr of dextral shear between Anatolia and Europeobserved by GPS occurs on the North Anatolian fault. We use18 mm/yr and the 250–300 year recurrence rate, as determined fromour trenching and the historical record, to suggest that each of theearthquakes observed in our trenches produced several meters of slip,consistent with their inferred sizes from the extent of historical damage. Considering that Istanbul has not suffered a large nearby event in theMarmara Sea since 1766, we suggest that about 4 m of strain hasaccumulated across faults in the Marmara during these past centuries. Thisis similar to the average slip in many of the large earthquakes on the NorthAnatolian fault this century. If released seismically, this could result in anearthquake in the M 7.2–M 7.6 range, similar to the August and November,1999 earthquakes east of the Marmara Sea. 相似文献
15.
16.
Progressive failure on the North Anatolian fault since 1939 by earthquake stress triggering 总被引：54，自引：0，他引：54
Ross S. Stein Aykut A. Barka James H. Dieterich 《Geophysical Journal International》1997,128(3):594-604
10 M ≥ 6.7 earthquakes ruptured 1000 km of the North Anatolian fault (Turkey) during 1939–1992, providing an unsurpassed opportunity to study how one large shock sets up the next. We use the mapped surface slip and fault geometry to infer the transfer of stress throughout the sequence. Calculations of the change in Coulomb failure stress reveal that nine out of 10 ruptures were brought closer to failure by the preceding shocks, typically by 1–10 bar, equivalent to 3–30 years of secular stressing. We translate the calculated stress changes into earthquake probability gains using an earthquake-nucleation constitutive relation, which includes both permanent and transient effects of the sudden stress changes. The transient effects of the stress changes dominate during the mean 10 yr period between triggering and subsequent rupturing shocks in the Anatolia sequence. The stress changes result in an average three-fold gain in the net earthquake probability during the decade after each event. Stress is calculated to be high today at several isolated sites along the fault. During the next 30 years, we estimate a 15 per cent probability of a M ≥ 6.7 earthquake east of the major eastern centre of Ercinzan, and a 12 per cent probability for a large event south of the major western port city of Izmit. Such stress-based probability calculations may thus be useful to assess and update earthquake hazards elsewhere. 相似文献
17.
This paper employs a computable general equilibrium model (CGE) to analyse how a carbon tax and/or a national Emissions Trading System (ETS) would affect macroeconomic parameters in Turkey. The modelling work is based on three main policy options for the government by 2030, in the context of Turkey’s mitigation target under its Intended Nationally Determined Contribution (INDC), that is, reducing greenhouse gas (GHG) emissions by up to 21% from its Business as Usual (BAU) scenario in 2030: (i) improving the productivity of renewable energy by 1% per annum, a target already included in the INDC, (ii) introducing a new flat rate tax of 15% per ton of CO2 (of a reference carbon price in world markets) imposed on emissions originating from carbon-intensive sectors, and (iii) introducing a new ETS with caps on emission permits. Our base path scenario projects that GHG emissions in 2030 will be much lower than Turkey’s BAU trajectory of growth from 430 Mt CO2-eq in 2013 to 1.175 Mt CO2-eq by 2030, implying that the government’s commitment is largely redundant. On the other hand, if the official target is assumed to be only a simple reduction percentage in 2030 (by 21%), but based on our more realistic base path, the government’s current renewable energy plans will not be sufficient to reach it.
Turkey’s official INDC is based on over-optimistic assumptions of GDP growth and a highly carbon-intensive development pathway;
A carbon tax and/or an ETS would be required to reach the 21% reduction target over a realistic base path scenario for 2030;
The policy options considered in this paper have some effects on major sectors’ shares in total value-added. Yet the reduction in the shares of agriculture, industry, and transportation does not go beyond 1%, while the service sector seems to benefit from most of the policy options;
Overall employment would be affected positively by the renewable energy target, carbon tax, and ETS through the creation of new jobs;
Unemployment rates are lower, economic growth is stronger, and households become better off to a larger extent under an ETS than carbon taxation.
18.
The Ilgin lignite field can be subdivided into the Haramiköy and Kurugöl areas which are separated by an area of basement and a fault. The lignite-bearing sequence consists mainly of fluvial and lacustrine Neogene deposits. The Ilgin lignite, averaging 8 m (up to 25 m) thick, is blackish brown and dark brown in colour. The lignite contains abundant brown wood, plant remains and white gastropod shells. Samples have an average of 38.9% moisture on an as-received basis and a mean of 3.9% total sulphur on an air-dried basis. Geochemical analysis, using an ICP-MS, was undertaken. Thirteen lignite core samples from three boreholes drilled in the Kurugöl area were ashed at 750°C. The average trace element contents of the lignite show a higher concentration of U (average 43 ppm) when compared to the range for most coals in the world, while the others (Ti, P, Sc, Be, Mn, Co, Cu, Zn, Ga, As, Rb, Sr, Zr, Nb, Mo, Cs, Ba, Y, Ta, W, Tl, Pb, Bi, Th, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu) agree with the global ranges. The Ilgin lignite is identified as of Middle Miocene (Middle Serravallian) age and occurs within lacustrine sediments deposited under subtropical climatic conditions. 相似文献
19.
Gökhan Demir Mustafa Aytekin Aykut Akgün Sabriye Banu İkizler Orhan Tatar 《Natural Hazards》2013,65(3):1481-1506
The North Anatolian Fault is known as one of the most active and destructive fault zones which produced many earthquakes with high magnitudes both in historical and instrumental periods. Along this fault zone, the morphology and the lithological features are prone to landslides. Kuzulu landslide, which is located near the North Anatolian Fault Zone, was triggered by snow melting without any precursor, occurred on March 17, 2005. The landslide resulted in 15 deaths and the destruction of about 30 houses at Kuzulu village. There is still a great danger of further landslides in the region. Therefore, it is vitally important to present its environmental impacts and prepare a landslide susceptibility map of the region. In this study, we used likelihood-frequency ratio model and analytical hierarchy process (AHP) to produce landslide susceptibility maps. For this purpose, a detailed landslide inventory map was prepared and the factors chosen that influence landslide occurrence were: lithology, slope gradient, slope aspect, topographical elevation, distance to stream, distance to roads, distance to faults, drainage density and fault density. The ArcGIS package was used to evaluate and analyze all the collected data. At the end of the susceptibility assessment, the area was divided into five susceptibility regions, such as very low, low, moderate, high and very high. The results of the analyses were then verified using the landslide location data and compared with the probability model. For this purpose, an area under curvature (AUC) and the seed cell area index assessments were applied. An AUC value for the likelihood-frequency ratio-based model 0.78 was obtained, whereas the AUC value for the AHP-based model was 0.64. The landslide susceptibility map will help decision makers in site selection and the site-planning process. The map may also be accepted as a basis for landslide risk-management studies to be applied in the study area. 相似文献
20.
Landslide susceptibility mapping for Ayvalik (Western Turkey) and its vicinity by multicriteria decision analysis 总被引：9，自引：5，他引：4
This paper presents the results of geographical information system (GIS)-based landslide susceptibility mapping in Ayvalık,
western Turkey using multi-criteria decision analysis. The methodology followed in the study includes data production, standardization,
and analysis stages. A landslide inventory of the study area was compiled from aerial photographs, satellite image interpretations,
and detailed field surveys. In total, 45 landslides were recorded and mapped. The areal extent of the landslides is 1.75 km2. The identified landslides are mostly shallow-seated, and generally exhibit progressive character. They are mainly classified
as rotational, planar, and toppling failures. In all, 51, 45, and 4% of the landslides mapped are rotational, planar, and
toppling types, respectively. Morphological, geological, and land-use data were produced using existing topographical and
relevant thematic maps in a GIS framework. The considered landslide-conditioning parameters were slope gradient, slope aspect,
lithology, weathering state of the rocks, stream power index, topographical wetness index, distance from drainage, lineament
density, and land-cover and vegetation density. These landslide parameters were standardized in a common data scale by fuzzy
membership functions. Then, the degree to which each parameter contributed to landslides was determined using the analytical
hierarchy process method, and the weight values of these parameters were calculated. The weight values obtained were assigned
to the corresponding parameters, and then the weighted parameters were combined to produce a landslide susceptibility map.
The results obtained from the susceptibility map were evaluated with the landslide location data to assess the reliability
of the map. Based on the findings obtained in this study, it was found that 5.19% of the total area was prone to landsliding
due to the existence of highly and completely weathered lithologic units and due to the adverse effects of topography and
improper land use. 相似文献