Medium-scale hazard mapping for shallow landslide initiation: the Buyukkoy catchment area (Cayeli, Rize, Turkey)   总被引：2，自引：0，他引：2  

Hakan A. Nefeslioglu  Candan Gokceoglu  Harun Sonmez  Tolga Gorum 《Landslides》2011,8(4):459-483

The main purpose of this study is to develop a new hazard evaluation technique considering the current limitations, particularly for shallow landslides. For this purpose, the Buyukkoy catchment area, located in the East Black Sea Region in the east of Rize province and the south of Cayeli district, was selected as the study area. The investigations were executed in four different stages. These were (1) preparation of a temporal shallow landslide inventory of the study area, (2) assessment of conditioning factors in the catchment, (3) susceptibility analyses and (4) hazard evaluations and mapping. A total of 251 shallow landslides in the period of 1955–2007 were recognised using different data sources. A ‘Sampling Circle’ approach was proposed to define shallow landslide initiation in the mapping units in susceptibility evaluations. To accomplish the susceptibility analyses, the method of artificial neural networks was implemented. According to the performance analyses conducted using the training and testing datasets, the prediction and generalisation capacities of the models were found to be very high. To transform the susceptibility values into hazard rates, a new approach with a new equation was developed, taking into account the behaviour of the responsible triggering factor over time in the study area. In the proposed equation, the threshold value of the triggering factor and the recurrence interval are the independent variables. This unique property of the suggested equation allows the execution of more flexible and more dynamic hazard assessments. Finally, using the proposed technique, shallow landslide initiation hazard maps of the Buyukkoy catchment area for the return periods of 1, 2, 5, 10, 50 and 100 years were produced.  相似文献   

Determination of radioactivity levels in Akhisar,Gördes,Gölmarmara and Sindirgi regions,Western Turkey     

Sermin Çam Kaynar  Muslim Murat Saç  F. Serap Ereeş 《Environmental Earth Sciences》2014,71(4):1581-1592

In this study, radioactivity measurements in the environment of Akhisar, Gölmarmara, Gördes and Sindirgi regions in Western Turkey were investigated in order to evaluate the implications of any excess radioactivity in the environment of geological formation. The radioactivity concentrations of ⁴⁰K, ²³⁸U and ²³²Th radionuclides in the soil samples were measured by a NaI(Tl) gamma spectrometer system, and the radium activity concentrations in the water samples were also analyzed by an ZnS(Ag) alpha counter by the collector chamber method. The radioactivity of ⁴⁰K, ²³⁸U and ²³²Th in soils ranged 2.80–2,347.77, 9.90–256.19 and 9.66–106.53 Bq kg^?1, respectively. The activity of ²²⁶Ra in the water samples ranged from 0.03 Bq L^?1 (0.89pCi/L) to 0.80 Bq L^?1 (21.58pCi/L). In addition, the external terrestrial gamma dose rate in air (nGy h^?1), annual effective dose rate (mSv year^?1) and radium equivalent activity (Bq kg^?1) were calculated and compared with international standard values.  相似文献   

AGE STRUCTURES OF MODULES OF CLONAL PEATLAND SEDGE Carex middendorffii     

Hkan RYDIN 《中国地理科学(英文版)》2005,15(3)

1IN T R O D U C T IO NIn theplantkingdom,phylafrom allevolutionarylevelsshow thecapacityforclonalgrowth(C ALLAGHAN etal.,1992).C lonalplantsarefound inallhabitat,sand inmany harshor stressfuelnvironments,such as peatlandswith poor nutrientsand high soilacidit,y they domi-nate.Clonal plantsinvade and occupy new habitatsandpersistforlong time.For example,V ASEK(1980)found an11000-year-oldclone of Larrea tridentate insouthwest of USA,and individualSphagnum clonesseem topersistformille…  相似文献   

First Ground-Based Photometry and Light Curve Analysis of the Recently Discovered Contact Binary Hx Uma     

S. Selam  B. Albayrak  M. Yilmaz  H. V. Şenavci  İ Özavci  C. Çetintaş 《Astrophysics and Space Science》2005,296(1-4):305-308

Photoelectric UBV light curves of the recently discovered eclipsing binary HX UMa were obtained and studied to determine the preliminary physical parameters of the system for the first time. The observations were taken at the TüBİTAK¹ – Turkish National Observatory (TUG) on three nights in April 2003. A simultaneous analysis of the light and radial velocity curves yields a typical A-type contact binary with a high degree of overcontact. The influence of the close visual companion to the total light of the system was taken into account during the analysis. ¹TüBİTAK: The Scientific and Technical Research Council of Turkey.  相似文献   

Spatial and temporal characterization of standard duration-maximum precipitation over Black Sea Region in Turkey     

Aksu  Hakan  Cetin  Mahmut  Aksoy  Hafzullah  Yaldiz  Sait Genar  Yildirim  Isilsu  Keklik  Gulsah 《Natural Hazards》2022,111(3):2379-2405

Natural Hazards - This study characterises the spatial and temporal behaviours of maximum precipitation over the Black Sea Region in northern Turkey. Maximum precipitation data of 14 standard...  相似文献   

PSHA of Van province for performance assessment using spectrally matched strong ground motion records     

Mustafa Kutanis  Hakan Ulutaş  Ercan Işik 《Journal of Earth System Science》2018,127(7):99

Within the framework of the performance based earthquake engineering, site specific earthquake spectra for Van province has been obtained. It is noteworthy that, in probabilistic seismic hazard assessment, as a first stage data from geological studies and records from the instrumental period were compiled to make a seismic source characterization for the study region. The probabilistic seismic hazard curves were developed based on selected appropriate attenuation relationships, at rock sites, with a probability of exceedance 2, 10 and 50% in 50 yrs period. The obtained results are compared with the spectral responses proposed for seismic evaluation and retrofit of building structure in Turkish Earthquake Code (2007), section 7. The acceleration response spectrums obtained from probabilistic seismic hazard analysis are matched to adjust earthquake accelerograms recorded during the 2011 Van earthquakes by using SeismoMatch v2.0 software. The aim of this procedure is to obtain a set of reasonable earthquake input motions for the seismic evaluation of existing buildings.  相似文献   

Geochemical,mineralogical and Re-Os isotopic constraints on the origin of Tethyan oceanic mantle and crustal rocks from the Central Pontides,northern Turkey     

Çelik  Ömer Faruk  Marzoli  Andrea  Marschik  Robert  Chiaradia  Massimo  Mathur  Ryan 《Mineralogy and Petrology》2018,112(1):25-44

Mineralogy and Petrology - Chromite, ultramafic and mafic rocks from Eldivan, Yapraklı, Ayli Dağ, Küre, Elekdağ and Kızılırmak in northern Turkey have been...  相似文献   

Investigation of vertical mass changes in the south of Izmir (Turkey) by monitoring microgravity and GPS/GNSS methods     

PAMUKÇU  OYA  GÖNENÇ  TOLGA  ÇIRMIK  AYÇA  SINDIRGI  PETEK  KAFTAN  İLKNUR  AKDEMIR  ÖZER 《Journal of Earth System Science》2015,124(1):137-148

Journal of Earth System Science - The monitoring of gravity changes in a region enables the investigation of regional structural elements depending upon the changes in load compensation. This...  相似文献   

MÉTHODE D'ÉTUDE DES DÉBITS PAR CORRÉLATION     

Jean-Pierre VANÇON 《水文科学杂志》2013,58(3):17-25

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The role of hydrogeology in solution-subsidence development and its environmental impacts; a case-study for Sazlıca (Niğde, Turkey)     

M. Çelik  M. Afşin 《Environmental Geology》1998,36(3-4):335-342

Solution-subsidence and other types of collapse failures developed in the vicinity of Sazlıca have been a major source of environmental problems such as groundwater pollution, soil erosion, and foundation failures. Extensive pumping of water from the Lake Dipsiz during irrigation seasons creates landslide developments at the shores of the lake. Five stages of landslide development were observed in the unconsolidated soils around Lake Dipsiz. Bowl-shaped solution-subsidence features with depths from 1 to 3 m and diameters between 1 and 60 m were formed due to excess pumping, and recharge and discharge features of unconfined aquifer. The pumping activities must be controlled to prevent further environmental problems. Lake Dipsiz and other subsidence developments are the groundwater exposure areas highly vulnerable to contamination. The proposed remedies for overcoming the environmental problems are the establishment of conservation areas around such natural features; ceasing the removal of top soil, controlling the urbanization, and keeping the livestock farming away from the areas susceptible to pollution. Received: 2 June 1997 · Accepted: 16 January 1998  相似文献