基于社区的台风灾害概率风险评估——以上海市杨浦区富禄里居委地区为例   总被引：2，自引：0，他引：2  

温家洪  黄蕙  陈珂  叶欣梁  胡恒智  华震阳 《地理科学》2012,(3):348-355

基于PGIS方法,以上海市杨浦区富禄里居委地区为案例,开展给定概率下的社区台风风险分析。结果表明,近60 a影响上海市区的台风中,最大风速大于17.2 m/s的超越概率(AEP)为12%。在此情景下,共有52幢建筑物(占全部建筑物的15.3%)有台风大风损失。上海市区最大的一次台风过程雨量达306.5 mm,其超越概率为1.8%。在该情景下,研究区地面积水最深处达0.61 m,有115幢建筑物(占全部建筑物的33.8%)有经济损失。在上述情景下,台风大风与过程雨量造成的损失对当地居民尚属可接受风险范围。  相似文献   

地震动力学与板块构造:地震灾害评估     

陈胜早 《高校地质学报》2005,11(4):512-520

作为地震灾害评估的理论基础,地震动力学主要研究与地震活动有关的断裂机制、破裂过程、震源辐射和由此而引起的地震波的传播及地面运动规律。对地震力学、震源辐射和能量释放等经典理论问题进行了系统研究。在此基础上,应用最新的定量地震学研究方法,以逻辑树的形式综合地震、地质和大地测量资料,提供了不同构造环境和断裂机制条件下地震灾害评估的概率分析和确定性分析实例。用于震源分析的典型构造类型包括板内地壳震源层、地壳活动断层及其速率、板块俯冲界面和俯冲板片。由于输入模型中不确定因素的存在,如输入参数的随机性和科学分析方法本身的不确定性,对分析结果的不确定性需审慎对待。通常对不同的模型或参量,包括地面衰减模型,进行加权平均可较为合理地减小结果的偏差：概率分析和确定性分析方法的结合亦为可取之有效途径。  相似文献   

Hillslope‐scale probabilistic characterization of soil moisture dynamics and average water balance     

Xingyao Pan  Nicholas J. Potter  Jun Xia  Lu Zhang 《水文研究》2013,27(10):1464-1474

Probabilistic water balance modelling provides a useful framework for investigating the interactions between soil, vegetation, and the atmosphere. It has been used to estimate temporal soil moisture dynamics and ecohydrological responses at a point. This study combines a nonlinear rainfall–runoff theory with probabilistic water balance model to represent varied source area runoff as a function of rainfall depth and a runoff coefficient at hillslope scale. Analytical solutions of the soil‐moisture probability density function and average water balance model are then developed. Based on a sensitivity analysis of soil moisture dynamics, we show that when varied source area runoff is incorporated, mean soil moisture is always lower and total runoff higher, compared with the original probabilistic water balance model. The increased runoff from the inclusion of varied source area runoff is mainly because of a reduction in leakage when the index of dryness is less than one and evapotranspiration when the index of dryness is greater than one. Inclusion of varied source area runoff in the model means that the actual evapotranspiration is limited by less available water (i.e. water limit), which is stricter than Budyko’s and Milly’s water limit. Application of the model to a catchment located in Western Australia showed that the method can predict annual value of actual evapotranspiration and streamflow accurately. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Probabilistic forecasting of hydrological events using geostatistical analysis / Prévision probabiliste d'événements hydrologiques par analyse géostatistique     

《水文科学杂志》2013,58(5)

Abstract

A method is introduced for probabilistic forecasting of hydrological events based on geostatistical analysis. In this method, the predictors of a hydrological variable define a virtual field such that, in this field, the observed dependent variables are considered as measurement points. Variography of the measurement points enables the use of the system of kriging equations to estimate the value of the variable at non-measured locations of the field. Non-measured points are the forecasts associated with specific predictors. Calculation of the estimation variance facilitates probabilistic analysis of the forecast variables. The method is applied to case studies of the Red River in Manitoba, Canada and Karoon River in Khoozestan, Iran. The study analyses the advantages and limitations of the proposed method in comparison with a K-nearest neighbour approach and linear and nonlinear multiple regression. The utility of the proposed method for forecasting hydrological variables with a conditional probability distribution is demonstrated.  相似文献   

Bearing capacity of strip footings on spatially random soils using sparse polynomial chaos expansion     

Tamara Al‐Bittar  Abdul‐Hamid Soubra 《国际地质力学数值与分析法杂志》2013,37(13):2039-2060

A probabilistic model is presented to compute the probability density function (PDF) of the ultimate bearing capacity of a strip footing resting on a spatially varying soil. The soil cohesion and friction angle were considered as two anisotropic cross‐correlated non‐Gaussian random fields. The deterministic model was based on numerical simulations. An efficient uncertainty propagation methodology that makes use of a non‐intrusive approach to build up a sparse polynomial chaos expansion for the system response was employed. The probabilistic numerical results were presented in the case of a weightless soil. Sobol indices have shown that the variability of the ultimate bearing capacity is mainly due to the soil cohesion. An increase in the coefficient of variation of a soil parameter (c or φ) increases its Sobol index, this increase being more significant for the friction angle. The negative correlation between the soil shear strength parameters decreases the response variability. The variability of the ultimate bearing capacity increases with the increase in the coefficients of variation of the random fields, the increase being more significant for the cohesion parameter. The decrease in the autocorrelation distances may lead to a smaller variability of the ultimate bearing capacity. Finally, the probabilistic mean value of the ultimate bearing capacity presents a minimum. This minimum is obtained in the isotropic case when the autocorrelation distance is nearly equal to the footing breadth. However, for the anisotropic case, this minimum is obtained at a given value of the ratio between the horizontal and vertical autocorrelation distances. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

基于非线性压缩的Menger空间上不动点与不动度定理     

靳鑫  肖建中 《南京气象学院学报》2013,5(5):472-477

首先,研究了Menger概率度量空间上的非线性算子,证明了非线性压缩与非线性扩张的不动点的存在唯一性;进一步将单个算子的不动点结果推广为一族可交换算子的公共不动点;最后,通过弱化条件,建立了模糊映射新的不动度定理.  相似文献   

基于概率神经网络的遥感影像分类方法     

巴桑  张正健  刘志红  李祚泳  侯长艳 《四川气象》2011,(3):26-29

在对数据进行归一化处理的基础上,将概率神经网络用于遥感影像分类,并探讨样本区的选择和高斯基函数标准差对分类精度的影响。用西藏波密地区1999年的TM遥感影像进行分类试验,并将分类结果和经典的最大似然法进行比较。结果表明：概率神经网络的总体分类精度和Kappa系数分别为94.5%和0.934,取得了较为理想的识别和分类效果。  相似文献   

Evaluation of the NMC Regional Ensemble Prediction System During the Beijing 2008 Olympic Games          下载免费PDF全文

LI Xiaoli  TIAN Hu  DENG Guo 《Acta Meteorologica Sinica》2011,25(5):568-580

Based on the B08RDP (Beijing 2008 Olympic Games Mesoscale Ensemble Prediction Research and Development Project) that was launched by the World Weather Research Programme (WWRP) in 2004, a regional ensemble prediction system (REPS) at a 15-km horizontal resolution was developed at the National Meteorological Center (NMC) of the China Meteorological Administration (CMA). Supplementing to the forecasters’ subjective affirmation on the promising performance of the REPS during the 2008 Beijing Olympic Games (BOG), this paper focuses on the objective verification of the REPS for precipitation forecasts during the BOG period. By use of a set of advanced probabilistic verification scores, the value of the REPS compared to the quasi-operational global ensemble prediction system (GEPS) is assessed for a 36-day period (21 July–24 August 2008). The evaluation here involves different aspects of the REPS and GEPS, including their general forecast skills, specific attributes (reliability and resolution), and related economic values. The results indicate that the REPS generally performs significantly better for the short-range precipitation forecasts than the GEPS, and for light to heavy rainfall events, the REPS provides more skillful forecasts for accumulated 6- and 24-h precipitation. By further identifying the performance of the REPS through the attribute-focused measures, it is found that the advantages of the REPS over the GEPS come from better reliability (smaller biases and better dispersion) and increased resolution. Also, evaluation of a decision-making score reveals that a much larger group of users benefits from using the REPS forecasts than using the single model (the control run) forecasts, especially for the heavy rainfall events.  相似文献   

冕宁县建筑物震害概率预测     

曾勇  何玉林 《四川地震》1992,(4):1-10

本文在进行冕宁县建筑物普查和建筑物抗震性能抽样调查的基础上,采用建筑物单体及群体震害概率预测方法,对冕宁县进行震害预测,给出了50年内各镇及广大农村的建筑震害预测结果,为该县防震减灾提供了科学的依据。  相似文献   

Seismic hazard analysis for the Philippines     

S. S. Su 《Natural Hazards》1988,1(1):27-44

Two sample probabilistic hazard maps for the Philippine Region are compiled. In these are shown various levels of expected horizontal ground acceleration for some given annual probability of exceedence, namely, for 0.1% a.p.e. and for 0.01% a.p.e. Such hazard maps are needed by structural engineers for compiling seismic zoning maps. The hazard maps are derived from source-zone or seismogenic maps, which, in turn, are compiled from seismographic, geologic, and geotectonic data. Much weight is put on geotectonic data rather than on seismographic data. The former lends support to extrapolating to much longer periods of exposure time or longer periods of recurrence.  相似文献