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51.
52.
Field survey of the 1994 Mindoro Island,Philippines tsunami   总被引:2,自引:0,他引:2  
This is a report of the field survey of the November 15, 1994 Mindoro Island, Philippines, tsunami generated by an earthquake (M=7.0) with a strike-slip motion. We will report runup heights from 54 locations on Luzon, Mindoro and other smaller islands in the Cape Verde passage between Mindoro and Luzon. Most of the damage was concentrated along the northern coast of Mindoro. Runup height distribution ranged 3–4 m at the most severely damaged areas and 2–4 in neighboring areas. The tsunami-affected area was limited to within 10 km of the epicenter. The largest recorded runup value of 7.3 m was measured on the southwestern coast of Baco Island while a runup of 6.1 m was detected on its northern coastline. The earthquake and tsunami killed 62 people, injured 248 and destroyed 800 houses. As observed in other recent tsunami disasters, most of the casualties were children. Nearly all eyewitnesses interviewed described the first wave as a leading-depression wave. Eyewitnesses reported that the main direction of tsunami propagation was SW in Subaang Bay, SE in Wawa and Calapan, NE on Baco Island and N on Verde Island, suggesting that the tsunami source area was in the southern Pass of Verde Island and that the wave propagated rapidly in all directions. The fault plane extended offshore to the N of Mindoro Island, with its rupture originating S of Verde Island and propagating almost directly south to the inland of Mindoro, thereby accounting for the relatively limited damage area observed on the N of Mindoro.  相似文献   
53.
Source models for the 1993 Hokkaido Nansei-Oki earthquake tsunami   总被引:1,自引:0,他引:1  
A source model for the 1993 Hokkaido Nansei-Oki tsunami must satisfy certain conditions. Such conditions are presented in this paper, and two methods are used to determine the best source model for this event. A trial-and-error method selects DCRC-17a as the best among 24 different models. This model has three fault planes dipping westward. To reproduce well the tide gauge records at two locations, an inversion analysis is used to modify the dislocation of DCRC-17a.  相似文献   
54.
《国际泥沙研究》2020,35(4):355-364
The scour and deposition pattern around an abutment under constant discharge condition is calculated using a three dimensional (3D) Computational Fluid Dynamics (CFD) model. The Reynolds-Averaged Navier Stokes (RANS) equations are solved in three dimensions using a CFD model. The Level Set Method (LSM) is used for calculation of both free surface and bed topography. The two-equation turbulence model (k-ε and k-ω) is used to calculate the eddy viscosity in the RANS equations. The pressure term in the RANS equations on a staggered grid is modeled using the Chorin's projection method. The 5th order Weighted Essentially Non-Oscillatory (WENO) scheme discretizes the convective term of the RANS equations. The Kovacs and Parker and Dey formulations are used for the reduction in bed shear stress on the sloping bed. The model also used the sandslide algorithm which limits bed shear stress reduction during the erosion process. The numerical model solution is validated against experimental results collected at the Politecnico di Milano, Milan, Italy. Further, the numerical model is tested for performance by varying the grid sizes and key parameters like the space and time discretization schemes. The effect of varying bed porosity has been evaluated. Overall, the free surface is well represented in a realistic manner and bed topography is well predicted using the Level Set Method (LSM).  相似文献   
55.
Simulation of acid water movement in canals   总被引:1,自引:0,他引:1  
An attempt to tackle the problem of the propagation of acid water in canals is described, and a mathematical model to simulate the acid water movement is developed, in which the jurbanite equilibrium is found to prevail. The processes of settling owing to sedimentation, precipitation and redissolution have been considered in the modelling. Data available from Tan Thanh, in the Plain of Reeds of the Mekong Delta in Viet Nam, are used as a case study.  相似文献   
56.
本文采用统一的处理模型和处理策略对中国-中南半岛地区地基北斗/GNSS测站2006—2016年历史观测数据进行高精度重处理和水汽反演,获得近10年的大气可降水含量(PWV)产品。基于北斗/GNSS PWV产品,研究了该地区大气水汽平均含量、年周期振幅和半年周期振幅等气候特征,发现这些特征主要受到了测站纬度、高程以及季风的影响。通过分析PWV同并址气象站降水观测的关联特性,揭示了该地区大气水汽含量同降水相关性随测站纬度减小而降低的特点(在云南相关系数可达0.8,在靠近赤道的泰国南部相关系数约为0.2)。此外,PWV和降水的距平值相关分析表明,相比于历史同期,大气水汽含量较高的月份在一定程度上对应着降水异常偏高,两者相关系数为0.2~0.4。  相似文献   
57.
Summary In many parts of the world, particularly in humid tropical regions, residual soils are abundant. In this paper the suitability of a residual lateritic soil as a construction material is investigated, with respect to its strength and compaction characteristics. In comparison with other typical construction fills available in Southeast Asia, compacted lateritic soils produce excellent shear strengths and CBR values. However, the brittleness and tensile cracking of this compacted material become enhanced on the dry side of the optimum moisture content, or if excessive compaction is imparted. Nevertheless, at a moisture content of 2% wetter than the optimum, the tensile mode of failure is suppressed and the lateritic fills become ideally suited for the construction of high embankments and impervious dam cores.  相似文献   
58.
南邦泪莫班塔西地区(370km2)是用矿产资源开发计划署提供的各种计算机程序进行首次地质综合研究的地区。通过SEDBA程序,150个以上数据组已被输入数据库。本文的地质图主要是由SUTOCAD程序完成的,磁性和放射性测量图主要是用GEOSOFT绘图系统软件包来处理和修饰的,而陆地卫星图象和投影图象是由MERIDIAN程序制备和修饰的。各种现有的信息,包括通过当前现有程序所获得的地质和遥感信息的数据汇编、提纯和解译,提高了地质制图及研究的质量。研究区主要由沉积于南部构造盆地中的沉积物两个群组成:时代最早的群为二叠纪动丕群(厚400m),产于东部,主要由开阔海陆架被动大陆边缘灰岩组成;二叠一三叠纪泪莫群(厚达200m)主要分布于东部,多数由东倾的与俯冲消减有关的火山岩和火山碎屑岩组成。时代最晚且分布最广的地层单元——三叠纪南邦群(3700m厚)为弧后沉降盆地的红一灰层、台地灰岩和厚层浊积岩。构造上,该区由一个在西北部和东部有小背斜的大向斜构成。航空地球物理数据和浅航天图象资料表明,该区曾属于与婚他和程逸主断层相平行的北东向断裂带。该区位于深浅不一的断裂基底之上。  相似文献   
59.
Salt-water encroachment in the multi-layer groundwater system underlying the Bangkok metropolitan area was simulated with a quasi-three-dimensional flow and solute-transport model. The quasi-three-dimensional model used in this study is based on the model SUTRA. Accurate conceptualization of the initial state of the system with regard to the distribution of salt-water concentration is very important for modeling, especially in areas where localized zones of high salt concentration exist in the groundwater. Data adequacy and model results were evaluated by a geostatistical analysis. The model is capable of simulating the regional trend of potentiometric levels and salt concentration. However, lack of monitoring data in areas where localized zones of high salt concentration exist resulted in large model residuals. RÉSUMÉ: L'empiétement des eaux salées dans le système hydrologique multi-couche sous-jacent la zone métropolitaine de Bangkok a été simulé à l'aide d'un modèle quasi-tridimensionnel représentant l'écoulement des eaux et le transport d'éléments en solution. Le modèle quasi-tridimensionnel utilisé dans cette étude est basé sur le modèle SUTRA. Une conceptualisation exacte de l'état initial du système en ce qui concerne la répartition de la concentration des eaux salines est très important, particulièrement dans les endroits localisés où l'eau souterraine presente une forte concentration en sel. La qualité des donnés et des résultats a été estimée à l'aide d'une analyse géostatistique. Le modèle est capable de simuler la tendance régionale des niveaux potentiométriques et de la concentration en sel. Cependant, le manque de données de contrôle dans les endroits à forte concentration a donné lieu à des résiduels importants. RESUMEN: La intrusión de agua salina en el sistema multicapa bajo el área metropolitana de Bangkok se simuló mediante un modelo de flujo y transporte de solutos casi-tridimensional, basado en el modelo SUTRA. La conceptualizacián precisa de la distribución inicial de concentraciones de agua salina es muy importante para el modelo, especialmente en áreas donde existen zonas locales de alta concentración salina en el agua subterránea. La exactitud de los datos y del modelo se evaluaron mediante un análisis geoestadístico. El modelo permite simular la tendencia regional de los niveles piezométricos y la concentración de sales. Sin embargo, la falta de datos de muestreo en las zonas locales de alta salinidad resultaron en valores altos de los residuos calculados por el modelo.  相似文献   
60.
We consider a late closed universe of which scale factor is a power function of time using observational data from combined WMAP5+BAO+SN Ia dataset and WMAP5 dataset. The WMAP5 data give power-law exponent, α=1.01 agreeing with the previous study of H(z) data while combined data gives α=0.985. Considering a scalar field dark energy and dust fluid evolving in the power-law universe, we find field potential, field solution and equation of state parameters. Decaying from dark matter into dark energy is allowed in addition to the non-interaction case. Time scale characterizing domination of the kinematic expansion terms over the dust and curvature terms in the scalar field potential are found to be approximately 5.3 to 5.5 Gyr. The interaction affects in slightly lowering the height of scalar potential and slightly shifting potential curves rightwards to later time. Mass potential function of the interacting Lagrangian term is found to be exponentially decay function.  相似文献   
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