Flood susceptibility mapping using frequency ratio and weights-of-evidence models in the Golastan Province,Iran     

Omid Rahmati  Hamid Reza Pourghasemi  Hossein Zeinivand 《国际地球制图》2016,31(1):42-70

Flood is one of the most devastating natural disasters with socio-economic and environmental consequences. Thus, comprehensive flood management is essential to reduce the flood effects on human lives and livelihoods. The main goal of this study was to investigate the application of the frequency ratio (FR) and weights-of-evidence (WofE) models for flood susceptibility mapping in the Golestan Province, Iran. At first, a flood inventory map was prepared using Iranian Water Resources Department and extensive field surveys. In total, 144 flood locations were identified in the study area. Of these, 101 (70%) floods were randomly selected as training data and the remaining 43 (30%) cases were used for the validation purposes. In the next step, flood conditioning factors such as lithology, land-use, distance from rivers, soil texture, slope angle, slope aspect, plan curvature, topographic wetness index (TWI) and altitude were prepared from the spatial database. Subsequently, the receiver operating characteristic (ROC) curves were drawn for produced flood susceptibility maps and the area under the curves (AUCs) was computed. The final results indicated that the FR (AUC = 76.47%) and WofE (AUC = 74.74%) models have almost similar and reasonable results. Therefore, these flood susceptibility maps can be useful for researchers and planner in flood mitigation strategies.  相似文献   

Application of partial least squares regression and WetSpa model to determine factors controlling sediment yield in Chardavol watershed,Iran     

Hossein Zeinivand 《国际地球制图》2017,32(4):386-400

This paper examines the effects of watershed complexity in terms of physiography and land use on the specific sediment yield of the Chardavol watershed (1012.946 km²) in Iran. First, specific sediment yield was simulated using spatially distributed hydrological WetSpa model, then the influential factors such as morphometric variables, land-use composition and pattern and soil properties of the watershed were calculated at the sub-watershed scale. Due to the inter-reliant of these watershed characteristics, a partial least squares regression (PLSR) was used to illustrate the relationship between the specific sediment yield and data of 15 selected watershed characteristics. The results showed that the land-use composition and soil properties had the maximum effects on the specific sediment yield and clarified 79% of the variation in the specific sediment yield. Regarding the availability of digital spatial database over the watershed, this simple PLSR procedure could be applied in different watersheds.  相似文献   

Biostratigraphy,Microfacies, Sedimentary Environments and Sequence Stratigraphy of the Late Devonian–Carboniferous Deposits at the Anarak Section,Central Iran     

Elaheh SATTARI  Ali BAHRAMI  Hossein VAZIRI-MOGHADDAM  Azizollah TAHERI  Iliana BONCHEVA 《《地质学报》英文版》2023,97(4):1038-1057

The Late Devonian–early Carboniferous deposits of the Anarak section in northeastern Isfahan, Central Iran, evaluated based on conodont biostratigraphy, sedimentary environment and sequence stratigraphy. According to the field observations, five lithological units were identified. Investigating the conodont fauna of the Late Devonian–Carboniferous(Mississippian–Pennsylvanian) deposits of Bahram, Shishtu, and Qaleh(Sardar 1) formations in Anarak section led to the identification of 67 species of ...  相似文献   

Reconstruction management policies in residential and commercial sectors after the 2003 bam earthquake in Iran   总被引：1，自引：1，他引：0  

Babak Omidvar  Hossein Zafari  Sahar Derakhshan 《Natural Hazards》2010,54(2):289-306

In the very early hours of 26th December 2003, a devastating and strong earthquake with a magnitude of 6.5 struck Bam, one of the historical cities of Kerman province in the south of Iran. According to the official reports, more than 30,000 were killed and about 25,000 injured. More than 80% of the town’s buildings were also destroyed. After the disaster, Bam’s reconstruction management process was presented with a lot of challenges and faced many fundamental questions. The number of human losses and related social issues, extensive destruction of the historical town, and also the lack of good experience in the reconstruction of a city or town made the reconstruction project of Bam more complicated. The reconstruction of Bam was the most important post-disaster reconstruction project among recent reconstructions in Iran. Many factors, such as concern over the government and international agencies, the new managerial approaches, and the application of appropriate reconstruction methods, made it different from the other reconstruction programs. Thus, the post-earthquake reconstruction of Bam is investigated in this research with respect to the importance of this issue. The aim behind this article is to give a brief explanation of the earthquake reconstruction management policies in Bam and also the plans for the reconstruction and rebuilding of urban residential and commercial units.  相似文献   

Comparison of classification and clustering methods in spatial rainfall pattern recognition at Northern Iran   总被引：1，自引：1，他引：0  

Saeed Golian  Bahram Saghafian  Sara Sheshangosht  Hossein Ghalkhani 《Theoretical and Applied Climatology》2010,102(3-4):319-329

Pattern recognition is the science of data structure and its classification. There are many classification and clustering methods prevalent in pattern recognition area. In this research, rainfall data in a region in Northern Iran are classified with natural breaks classification method and with a revised fuzzy c-means (FCM) algorithm as a clustering approach. To compare these two methods, the results of the FCM method are hardened. Comparison proved overall coincidence of natural breaks classification and FCM clustering methods. The differences arise from nature of these two methods. In the FCM, the boundaries between adjacent clusters are not sharp while they are abrupt in natural breaks method. The sensitivity of both methods with respect to rain gauge density was also analyzed. For each rain gauge density, percentage of boundary region and hardening error are at a minimum in the first cluster while the second cluster has the maximum error. Moreover, the number of clusters was sensitive to the number of stations. Since the optimum number of classes is not apparent in the classification methods and the boundary between adjacent classes is abrupt, use of clustering methods such as the FCM method, overcome such deficiencies. The methods were also applied for mapping an aridity index in the study region where the results revealed good coincidence between the FCM clustering and natural breaks classification methods.  相似文献   

Vibration analysis of rectangular Mindlin plates on elastic foundations and vertically in contact with stationary fluid by the Ritz method     

Sh. Hosseini Hashemi  Mahmoud Karimi  H. Rokni Damavandi Taher 《Ocean Engineering》2010,37(2-3):174-185

In this study Free vibration analysis of vertical rectangular Mindlin plates resting on Pasternak elastic foundation and fully or partially in contact with fluid on their one side is investigated for different combinations of boundary conditions. The plate is assumed to be one of vertical rectangular walls of a container in contact with fluid. In order to analyze the interaction of the Mindlin plate with the elastic foundation and fluid system, three displacement components of the plate are expressed in the Ritz method by adopting a set of static Timoshenko beam functions satisfying geometric boundary conditions in a Cartesian co-ordinate system. The method of separation of variables and the method of Fourier series expansion is used to model fluid and to obtain the exact expression of the motion of fluid in the form of integral equations. The fluid domain is finite in depth and width but infinite in the length direction. To demonstrate the accuracy of the present solution, convergence study is first carried out and then a few comparison studies are carried out with the available data in the literature. Finally, natural frequencies of rectangular plates are presented in tabular and graphical forms for different fluid levels, foundation parameters, aspect ratios, thickness to width ratios and boundary conditions.  相似文献   

The crystalline complexes of Hamadan (Sanandaj–Sirjan zone, western Iran): metasedimentary Mesozoic sequences affected by Late Cretaceous tectono-metamorphic and plutonic events     

Aliakbar Baharifar  Hossein Moinevaziri  Herv Bellon  Alain Piqu 《Comptes Rendus Geoscience》2004,336(16):1443-1452

The Hamadan area is characterised by various metamorphic rocks where the slates yielded Jurassic fossils. The entire column, representing the Mesozoic from at least the Jurassic to the Mid-Cretaceous, has been affected by tectono-metamorphic events and the emplacement of Late Cretaceous granitic rocks. A timing of these events is based on the ⁴⁰K–⁴⁰Ar ages carried mainly on separated amphiboles, biotites and muscovites, and interpreted as the ages of their isotopic closure. Results are ranging between 91 and 70 Ma. To cite this article: A. Baharifar et al., C. R. Geoscience 336 (2004).

Résumé

La région de Hamadan expose des roches métamorphiques dont les termes les moins transformés contiennent des fossiles jurassiques. Au cours du Crétacé supérieur, elle a été affectée par un événement tectono-métamorphique régional et elle a été le siège d'une activité plutonique. Les résultats des datations ⁴⁰K–⁴⁰Ar des amphiboles et des micas séparés des roches métamorphiques et plutoniques qui s'étagent entre 91 et 70 Ma montrent l'importance de ces événements et leur étalement au cours du Crétacé supérieur. Pour citer cet article : A. Baharifar et al., C. R. Geoscience 336 (2004).  相似文献   

Lithospheric structure of the Tornquist Zone resolved by nonlinear P and S teleseismic tomography along the TOR array   总被引：1，自引：1，他引：1  

Z. Hossein Shomali  Roland G. Roberts  Laust B. Pedersen  the TOR Working Group 《Tectonophysics》2006,416(1-4):133

The main aim of the TOR project is to study the lithospheric–asthenospheric boundary structure under the Sorgenfrei–Tornquist Zone, across northern Germany, Denmark and southern Sweden. Relative arrival-time residuals of teleseismic P and S phases from 51 earthquakes, recorded by 150 seismic stations along the TOR array, were used to delineate the transition zone in the studied area. The effects of crustal structures were investigated by correcting the teleseismic residuals for travel-time variations in the crust based on a 3D crustal model derived from other data. The inversion was carried out for S phases. The results were then compared with the corresponding P-wave models. As expected, the derived models show that the relatively old and cold Baltic Shield has higher velocity at depth than the younger lithosphere farther South. The models show two sharp and distinct increases in depth to velocities which are low compared to our reference model, as we move from South to North. The location and sharpness of these boundaries suggests that the features resolved are, at least partially, compositional in origin, presumably related to mantle depletion. A sharp and steep subcrustal boundary is found roughly coincident with the southern edge of Sweden. This is below where the edge of the Baltic Shield is usually placed, based on surface geological evidence (the Sorgenfrei–Tornquist Zone). Another less significant transition is recognised more or less beneath the Elbe-lineament. Relatively high d(V_p / V_s) ratios under the central part of the profile (Denmark) indicate relatively low S-velocity in an area where a gravity high supports the hypothesis of extensive mafic intrusions.  相似文献   

Transient scattering of elastic waves by dipping layers of arbitrary shape. Part 2: Plane strain model     

Hossein Eshraghi  Marijan Dravinski 《地震工程与结构动力学》1989,18(3):417-434

Scattering of elastic waves by dipping layers of arbitrary shape embedded within an elastic half-space is investigated for a plane strain model by using a boundary method. Unknown scattered waves are expressed in the frequency domain in terms of wave functions which satisfy the equations of motion and appropriate radiation conditions at infinity. The steady state displacement field is evaluated throughout the elastic medium for different incident waves so that the continuity conditions along the interfaces between the layers and the traction-free conditions along the surface of the half-space are satisfied in the least-squares sense. Transient response is constructed from the steady state one through the Fourier synthesis. The results presented show that scattering of waves by dipping layers may cause locally very large amplification of surface ground motion. This amplification depends upon the type and frequency of the incident wave, impedance contrast between the layers, component of displacement which is being observed, location of the observation station and the geometry of the subsurface irregularity. These results are in agreement with recent experimental observations.  相似文献   

Non-linear body wave teleseismic tomography along the TOR array   总被引：2，自引：0，他引：2  

Z. Hossein Shomali  Roland G. Roberts  the TOR Working Group 《Geophysical Journal International》2002,148(3):562-574

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