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31.
We conducted archaeological and geophysical surveys in order to investigate the submergence of ancient constructions along the coast at Kekova Island in southern Turkey. Submerged archaeological remains were measured with respect to present sea level, and geological features that may have caused subsidence were determined by seismic investigation. We estimated relative sea‐level change taking into account presumed original elevation of constructions associated with the harbor at the time of occupation and compared our results with eustatic–isostatic sea‐level studies in the Mediterranean. Ceramics found along the submerged quay of Kekova Island provided evidence for the time of last use of the harbor structures and suggest that submergence began during the early Byzantine period. Considering relative sea‐level changes, eustatic–isostatic effects, and the period of submergence, we estimate a rate of coastal tectonic subsidence of at least 1.6 mm/yr over the last 1400 years. 相似文献
32.
Susceptibility assessments of shallow earthflows triggered by heavy rainfall at three catchments by logistic regression analyses 总被引：11，自引：3，他引：11
Tolga Can Hakan A. Nefeslioglu Candan Gokceoglu Harun Sonmez Tamer Y. Duman 《Geomorphology》2005,72(1-4):250-271
Sometimes regional meteorological anomalies trigger different types of mass movements. In May 1998, the western Black Sea region of Turkey experienced such a meteorological anomaly. Numerous residential and agricultural areas and engineering lifelines were buried under the flood waters. Besides the reactivation of many previously delineated landslides, thousands of small-scale landslides (mostly the earthflow type) occurred all over the region. The earthflows were mainly developed in flysch-type units, which have already presented high landslide concentrations. In this study, three different catchments — namely Agustu, Egerci, and Kelemen — were selected because they have the most landslide-prone geological units of the region. The purposes of the present study are to put forward the spatial distributions of the shallow earthflows triggered, to describe the possible factors conditioning the earthflows, and to produce the shallow earthflow susceptibility maps of the three catchments. The unique condition units (UCU) were employed during the production of susceptibility maps and during statistical analyses. The unique condition units numbered 4052 for the Agustu catchment, 13,241 for the Egerci catchment and 12,314 for the Kelemen catchment. The earthflow intensity is the highest in the Agustu catchment (0.038 flow/UCU) and lowest in the Egerci catchment (0.0035 flow/UCU). Logistic regression analyses were also employed. However, during the analyses, some difficulties were encountered. To overcome the difficulties, a series of sensitivity analyses were performed based on some decision rules introduced in the present study. Considering the decision rules, the proper ratios of UCU free from earthflow (0) / UCU including the earthflow (1) for the Agustu, Egerci and Kelemen catchments were obtained as 3, 6, and 5, respectively. Also, a chart for the proper ratio selection was developed. The regression equations from the selected ratios were then applied to the entire catchment and the earthflow susceptibility maps were produced. The landslide susceptibility maps revealed that 15% of the Agustu catchment, 8% of the Egerci catchment, and 7% of the Kelemen catchment have very high earthflow susceptibility; and most of the earthflows triggered by the May 1998 meteorological event were found in the very high susceptibility zones. 相似文献
33.
Ibrahim Gürer Harun Tunçel Ö. Murat Yavaş Tarhan Erenbılge Ayhan Sayin 《Natural Hazards》1995,11(1):1-16
Snow avalanches take place in the mountainous regions of Turkey mostly in the eastern Anatolia Region with an average annual death toll of 23 people and much damage to property. However, in the mountainous areas of the Kastamonu and Sinop provinces in the western part of the Black Sea Region of Turkey between 25 and 30 December 1992, blizzards with heavy snowfall caused roof collapses and major avalanche events whereby 16 people were killed and 2 injured. When past records were investigated, there was no evidence that avalanche accidents had been encountered in the region where the dominant precipitation type is rain in the coastal zones and snow over the mountains. Moreover, avalanche prevention measures are so limited that the resettlement of villages or hamlets located in risk zones is common practice. In this article, avalanche formation associated with the meteorological conditions and geomorphologic features is discussed.This study was partially supported by Tübitak (Scientific and Technical Research Council of Turkey) with Project No. YBAG-0067. 相似文献
34.
Since the commencement of mining at the Himmetoğlu coal mine, northwest Turkey, serious stability problems have led to interruptions
in mining and some environmental effects. A geotechnical investigation was initiated in 1997 and the significant factors that
influence the stability have been defined. This paper outlines the results of the field and laboratory studies associated
with the causes and mechanism of the slope instabilities and their environmental impacts. The possible remedial measures to
improve the stability and to minimize the environmental problems are also described. Back-analyses and data from long-term
monitoring indicate that the failures occur along two or three planar surfaces by combination of faults and localized strata
steepening adjacent to the faults. The stability is sensitive to changes in length of the lower part of the basal sliding
surface and shear strength of the bedding surfaces in the overburden. Suitable remedial measures include slope flattening
(i.e. staged bench stripping), proper drainage and spreading of a rock blanket on the pit floor to increase spoil pile stability.
Received: 18 April 2000 · Accepted: 15 August 2000 相似文献
35.
Harun Ciftci 《洁净——土壤、空气、水》2010,38(7):657-662
In this study, a new solid‐phase extraction procedure has been developed for preconcentration and determination of Co ions in different water samples by flame atomic absorption spectrometry (FAAS). Cobalt was preconcentrated as N,N′‐bis(pyridine‐2‐yl‐methyl)benzene‐1,4‐diamine (Co‐BPMBDA) from sample solutions using a column containing Amberlite XAD‐7 and was determined. In order to achieve the best performance for the method, effects of several parameters such as pH, concentrations of ligand, sample flow rate, eluent, and matrix ions on the method efficiency were investigated. Under optimum conditions, the preconcentration factor was found to be 200 for 1000 mL waters samples. Detection limit based on the 3Sb criterion was calculated as 0.24 µg/L for 100 mL of sample solution and relative standard deviation was found to be 1.8%. The method was applied to determine the trace amounts of cobalt in water samples. 相似文献