Seismic hazard assessment of Tehran,Iran with emphasis on near-fault rupture directivity effects          下载免费PDF全文

Ehsan Bazarchi  Reza Saberi  Majid Alinejad 《地震科学（英文版）》2018,31(1):1-11

Many destructive earthquakes happened in Tehran, Iran in the last centuries. The existence of active faults like the North Tehran is the main cause of seismicity in this city. According to past investigations, it is estimated that in the scenario of activation of the North Tehran fault, many structures in Tehran will collapse. Therefore, it is necessary to incorporate the near field rupture directivity effects of this fault into the seismic hazard assessment of important sites in Tehran. In this study, using calculations coded in MATLAB,Probabilistic Seismic Hazard Analysis(PSHA) is conducted for an important site in Tehran. Following that, deaggregation technique is performed on PSHA and the contribution of seismic scenarios to hazard is obtained in the range of distance and magnitude. After identifying the North Tehran fault as the most hazardous source affecting the site in 10000-year return period, rupture directivity effects of this fault is incorporated into the seismic hazard assessment using Somerville et al.(1997) model with broadband approach and Shahi and Baker(2011) model with narrowband approach. The results show that the narrowband approach caused a 27% increase in the peak of response spectrum in 10000-year return period compared with the conventional PSHA. Therefore, it is necessary to incorporate the near fault rupture directivity effects into the higher levels of seismic hazard assessment attributed to important sites.  相似文献   

Effect of ENSO on annual maximum floods and volume over threshold in the southwestern region of Iran     

Bahram Saghafian  Amin Haghnegahdar  Majid Dehghani 《水文科学杂志》2017,62(7):1039-1049

In this paper, the effects of the El Niño-Southern Oscillation (ENSO) on the annual maximum flood (AMF) and volume over threshold (VOT) in two major neighbouring river basins in southwest Iran are investigated. The basins are located upstream of the Dez and Karun-I dams and cover over 40?000 km² in total area. The effects of ENSO on the frequency, magnitude and severity (frequency times magnitude) of flood characteristics over the March–April period were analysed. ENSO indices were also correlated with both AMF and VOT. The results indicate that, in the Dez and Karun basins, the El Niño phenomenon intensifies March–April floods compared with neutral conditions. The opposite is true in La Niña conditions. The degree of the effect is more intense in the El Niño period.  相似文献   

Aftershock collapse fragility curves for non‐ductile RC buildings: a scenario‐based assessment          下载免费PDF全文

Marco Gaetani d'Aragona  Maria Polese  Kenneth J. Elwood  Majid Baradaran Shoraka  Andrea Prota 《地震工程与结构动力学》2017,46(13):2083-2102

Recent studies have addressed the computation of fragility curves for mainshock (MS)‐damaged buildings. However, aftershock (AS) fragilities are generally conditioned on a range of potential post‐MS damage states that are simulated via static or dynamic analyses performed on an intact building. Moreover, there are very few cases where the behavior of non‐ductile reinforced concrete buildings is analyzed. This paper presents an evaluation of AS collapse fragility conditioned on various return periods of MSs, allowing for the rapid assessment of post‐earthquake safety variations based solely on the intensity of the damaging earthquake event. A refined multi‐degree‐of‐freedom model of a seven‐storey non‐ductile building, which includes brittle failure simulations and the evaluation of a system level collapse, is adopted. Aftershock fragilities are obtained by performing an incremental dynamic analysis for a number of MS–AS ground motion sequences and a variety of MS intensities. The AS fragilities show that the probability of collapse significantly increases for higher return periods for the MS. However, this result is mainly ascribable to collapses occurred during MSs. When collapse cases that occur during a MS are not considered in the assessment of AS collapse probability, a smaller shift in the fragility curves is observed as the MS intensity increases. This result is justified considering the type of model and collapse modes introduced, which strongly depend on the brittle behavior of columns failing in shear or due to axial loads. The analysis of damage that is due to MSs when varying the return period confirms this observation. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

Bacteria Elimination and SO2 Filtration Using Spacer Fabric Loaded With Natural Zeolite‐Nanosilver Composites          下载免费PDF全文

Mohammad Mehdi Shirmohammadi‐Bahadoran  Majid Montazer  Mehdi Kamali Dolatabadi  Abbas Bahador 《洁净——土壤、空气、水》2018,46(9)

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Modeling habitat suitability of range plant species using random forest method in arid mountainous rangelands     

Hossein Piri Sahragard  Majid Ajorlo  Peyman Karami 《山地科学学报》2018,15(10):2159-2171

Mountainous rangelands play a pivotal role in providing forage resources for livestock, particularly in summer, and maintaining ecological balance. This study aimed to identify environmental variables affecting range plant species distribution, ecological analysis of the relationship between these variables and the distribution of plants, and to model and map the plant habitats suitability by the Random Forest Method(RFM) in rangelands of the Taftan Mountain, Sistan and Baluchestan Province, southeastern Iran. In order to determine the environmental variables and estimate the potential distribution of plant species, the presence points of plants were recorded by using systematic random sampling method(90 points of presence) and soils were sampled in 5 habitats by random method in 0–30 and 30–60 cm depths. The layers of environmental variables were prepared using the Kriging interpolation method and Geographic Information System facilities. The distribution of the plant habitats was finally modelled and mapped by the RFM. Continuous maps of the habitat suitability were converted to binary maps using Youden Index(?) in order to evaluate the accuracy of the RFM in estimation of the distribution of species potentialhabitat. Based on the values of the area under curve(AUC) statistics, accuracy of predictive models of all habitats was in good level. Investigating the agreement between the predicted map, generated by each model, and actual maps, generated from fieldmeasured data, of the plant habitats, was at a high level for all habitats, except for Amygdalus scoparia habitat. This study concluded that the RFM is a robust model to analyze the relationships between the distribution of plant species and environmental variables as well as to prepare potential distribution maps of plant habitats that are of higher priority for conservation on the local scale in arid mountainous rangelands.  相似文献   

Studying the effects of deformable panels on seismic displacement of gravity quay walls     

Amirali Mostafavi Moghadam  Abbas Ghalandarzadeh  Ikuo Towhata  Majid Moradi  Babak Ebrahimian  Pourya Hajialikhani 《Ocean Engineering》2009,36(15-16):1129-1148

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A new flow for Canadian young hydrologists: Key scientific challenges addressed by research cultural shifts     

Caroline Aubry-Wake  Lauren D. Somers  Haley Alcock  Aspen M. Anderson  Amin Azarkhish  Samuel Bansah  Nicole M. Bell  Kelly Biagi  Mariana Castaneda-Gonzalez  Olivier Champagne  Anna Chesnokova  Devin Coone  Tasha-Leigh J. Gauthier  Uttam Ghimire  Nathan Glas  Dylan M. Hrach  Oi Yin Lai  Pierrick Lamontagne-Hallé  Nicolas R. Leroux  Laura Lyon  Sohom Mandal  Bouchra R. Nasri  Nataša Popović  Tracy E. Rankin  Kabir Rasouli  Alexis Robinson  Palash Sanyal  Nadine J. Shatilla  Brandon Van Huizen  Sophie Wilkinson  Jessica Williamson  Majid Zaremehrjardy 《水文研究》2020,34(8):2001-2006

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Modeling Local Tidal Constituents Using TOPEX/POSEIDON SSH for the Malaysian Marine Region     

Muhammad Nur J. P. Vella  Sahrum Ses  Majid Kadir  Koji Matsumoto 《Marine Geodesy》2013,36(2):99-106

A new Local Ocean Tide Model, has been produced for the Exclusive Economic Zone (EEZ) of Malaysia, which incorporates some of the latest TOPEX/POSEIDON data for the years 1992 to 1998. Local tide gauge data are used as a comparison, along with another leading Global Ocean Tide Model, Ori96. The leading diurnal and semidiurnal constituents M₂, S₂, N₂, K₁, O₁, P₁ and Q₁ are reproduced using TOPEX/POSEIDON Sea Surface Heights (SSH) in a response analysis type least squares derivation following Munk and Cartwright (1966).  相似文献   

Training Workshop on Quaternary Setup of Arid NW Himalaya: Main focus on Ladakh     

Yogesh Ray  Naresh Rana  Zaheed Majid  Pritam Chand 《Journal of the Geological Society of India》2012,80(6):874-875

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Vertically sheared horizontal flow with mass sources: a canonical balanced model     

Andrew J. Majda  Majid Mohammadian  Yulong Xing 《地球物理与天体物理流体动力学》2013,107(6):543-591

Canonical balanced dynamic equations involving vertically sheared horizontal flow with heat or mass sources have emerged recently in systematic multi-scale modeling of the equatorial wave guide on a wide range of spatio-temporal scales. Here, a new self-contained derivation of these equations is developed briefly in a context for potential applications to the hurricane embryo. These canonical balanced equations are studied through a combination of exact solutions and simple numerics. The results below include elementary exact solutions given by velocity fields that are linear in the spatial coordinates combined with an exact nonlinear stability analysis for vertical vorticity amplification in such a preconditioned environment. Other elementary solutions studied here include the evolution of radial eddies, which represent “hot towers” in the hurricane embryo in a suitable radial preconditioned background environment.  相似文献