Bayesian analysis of marked stress release models for time-dependent hazard assessment in the western Gulf of Corinth     

R. Rotondi  E. Varini   《Tectonophysics》2006,423(1-4):107

We consider point processes defined on the space–time domain which model physical processes characterized qualitatively by the gradual increase over time in some energy until a threshold is reached, after which, an event causing the loss of energy occurs. The risk function will, therefore, increase piecewise with sudden drops in correspondence to each event. This kind of behaviour is described by Reid's theory of elastic rebound in the earthquake generating process where the quantity that is accumulated is the strain energy or stress due to the relative movement of tectonic plates. The complexity and the intrinsic randomness of the phenomenon call for probabilistic models; in particular the stochastic translation of Reid's theory is given by stress release models. In this article we use such models to assess the time-dependent seismic hazard of the seismogenic zone of the Corinthos Gulf. For each event we consider the occurrence time and the magnitude, which is modelled by a probability distribution depending on the stress level present in the region at any instant. Hence we are dealing here with a marked point process. We perform the Bayesian analysis of this model by applying the stochastic simulation methods based on the generation of Markov chains, the so called Markov chain Monte Carlo (MCMC) methods, which allow one to reconcile the model's complexity with the computational burden of the inferential procedure. Stress release and Poisson models are compared on the basis of the Bayes factor.  相似文献   

永城矿区煤矿排水钻孔施工技术   总被引：1，自引：0，他引：1  

王佟  王遂正 《中国煤炭地质》2008,20(2):65-66

永城矿区某矿排水钻孔设计孔深584．1m,因钻孔与地下巷道平面位置相距仅15m,因此要求钻孔偏斜在表土层不大于0.3％,基岩段不大于0.5％。施工中选用稳定性好、扭矩力大的TSJ-2000型工程钻机,并配置850／5型泥浆泵进行钻井作业,钻进过程中严格控制钻进参数,并采取不同措施防止钻孔偏斜。井管加工严格执行技术标准,并在准备工作充分的情况下,一次安放到位。采用向管内连续注入泥浆,通过管底凡尔返到管外的方法进行井管壁外注浆。在注浆作业完成后72h．排除管内泥浆,完成排水钻孔施工。  相似文献   

西南经济核心区中心城市城镇化结构质量比较分析——以成都、重庆为例     

孙平军  罗宁 《地理科学》2021,41(6):1019-1029

运用耦合协调模型和基于主成分的多元线性回归法,对2005—2017年间中国西南经济核心区中心城市成都和重庆的城镇化结构质量及其驱动力展开对比分析。结果表明：① 重庆与成都的城镇化结构质量整体水平较高且在持续增长中;成都的城镇化结构质量明显高于重庆,这与因地形、发展阶段、城市定位而限定的重庆“主城区现代化大都市+非主城区广大农村地域”、成都现代化都市圈的空间结构组织形式密切相关;② 城镇化驱动因子呈现多元化、阶段性与差异性特征,行政力和市场力起主要作用;其次是内源力和外向力,但外向力正处在一个不断弱化的过程,反映中国城镇化发展的内生性特征;③ 基于取平均值的城镇化子系统及其系统耦合协调性分析,可有效避免当前城镇化耦合分析中因各子系统指标选取个数不等而带来的失真、不准确问题。  相似文献   

1961-2018年淮河流域热浪事件时空变化特征   总被引：2，自引：0，他引：2  

王文  胡彦君  徐川怡 《地理科学》2021,41(5):911-921

利用淮河流域1961—2018年逐日最高气温与平均气温格点数据,在对基于绝对阈值和相对阈值的热浪事件识别方法进行改进的基础上,分析了逐年的热浪强度、烈度、频次、最长历时等时空变化特征。结果表明,淮河流域基于固定气温阈值的绝对热浪（>35 ℃）的多年平均强度为10.27 ℃、烈度为1.82 ℃,频次为1.3次;基于热浪指数的相对热浪多年平均强度为2.27、烈度为0.63,频次为1.0次。空间分布上,绝对热浪多发于流域西部除边缘山地的内陆地区（支流沙颖河流域）,相对热浪多发于流域西南地区（淮河干流中上游）,总体上流域东北部丘陵地区及东南近海地区的绝对、相对热浪均较弱（少）;时间变化上,淮河流域的热浪事件具有显著的趋势性突变,在20世纪60年代初至80年代早期（约1982—1985年）呈减弱（少）趋势,此后呈增强（多）趋势。  相似文献   

情理整合视角下旅游者环境责任行为与意愿悖离研究——基于Logistic-ISM模型     

段正梁  彭振  杨左  鲍青  阮氏莲 《热带地理》2021,41(1):104-113

基于对岳麓山景区447位旅游者的实地调研,运用拓展的计划行为理论并结合Logistic回归模型,分析影响两者发生悖离的因素,并进一步利用ISM解释结构模型分析各因素之间的逻辑关系。从Logistic回归结果看,旅游者的行为态度、感知行为控制等相关理性认知越好,发生悖离的可能性越低;旅游者积极环境情感和消极环境情感对悖离均有负向作用,相关环境情感越强烈,发生悖离的可能性越低;年龄越大、受教育程度越高,旅游者环境责任行为与意愿越一致;在性别方面,男性悖离度高于女性。从解释结构模型结果来看,积极环境情感和消极环境情感是表层直接因素,行为态度和感知行为控制是中间间接因素,旅游者性别、受教育程度和年龄是深层根源因素。  相似文献   

江西省农户生态耕种采纳意愿与行为悖离研究   总被引：1，自引：0，他引：1  

刘艳婷  陈美球  谢贤鑫 《地域研究与开发》2021,40(2):118-123

利用Tobit-ISM模型分析江西省农户生态耕种采纳意愿与行为悖离度影响因素,进一步解析各影响因素间的层次结构。结果表明:70%的农户具有生态耕种意愿,但仅部分农户发生了采纳行为,证实了农户生态耕种采纳意愿与行为发生悖离。通过Tobit回归模型分析文化程度、生态耕种培训、农户态度、耕地面积、生态环境污染认知、环保法规认知、风险认知、相互交流和自然资源状况对悖离度的发生表现出负向作用,而非农收入比重则具有正向影响;通过ISM模型分析农户态度、耕地面积、自然资源状况是表层因素,生态耕种污染认知、环保法规认知、风险认知是中间层因素,文化程度、生态耕种培训、非农收入比重、相互交流是深层次因素。  相似文献   

The hurst effect and its implications for extrapolating process rates     

M. J. Kirkby 《地球表面变化过程与地形》1987,12(1):57-67

In long-term records of climatic or hydrological events, persistent periods of high and low values are measured by the ‘rescaled range’, which is defined for a sequence of n consecutive values. As n increases the rescaled range for historic sequences increases as n^H for 0·5 < H < = 1. This is the Hurst effect. Sequences of independent random events give H = 0·5, while sequences in which the values are successive positions of a random walk (i.e. the sum of independent events) give H = 1. Intermediate values of H may be obtained from fractal sequences, from sequences with a steadily changing mean, or through a storage model. In all but the fractal case H exceeds 0·5 for a time related to the duration of the changing mean or the response time of the store. An exponential storage model has been explored in some detail. Storage models have the advantage of offering a plausible physical mechanism for persistence. Analysis of simulated sequences shows that the Hurst effect is evident for about 30 x the response time of the store, so that relatively modest store sizes are enough to explain observed Hurst effects over available periods of record. Comparison with empirical values shows that high H values seem to be associated with large physical stores. Whether the Hurst effect is due to storage effects or climatic or other change imposed from outside, the effect on longterm process rates is strong. Short-term measurements of process rates show compressed variances and simple extrapolation is likely to produce large errors. If it is assumed that long-term rates are strongly influenced by climatic variables, then measurements may be used to obtain parameters of a climatic model for differences in process rates. Errors in extrapolation will be least where the model has a sound physical basis. A first implication for magnitude and frequency distributions is that the sequence of events may be as important as their distribution over time in determining process impact. A second conclusion is that the geomorphic history of an area is inevitably dominated by a sequence of larger and larger events receding into the past, and that the Hurst exponent over geologic time-spans measures the extent of that domination.  相似文献   

中国东、中、西三大地区水资源绿色效率时空演变特征与收敛性分析   总被引：1，自引：0，他引：1  

孙才志  马奇飞  赵良仕 《地理科学进展》2018,37(7):901-911

本文基于SBM模型,通过构建共同前沿和群组前沿函数,分析了中国东、中、西部三大地区水资源绿色效率的时空差异及空间重心转移规律,并对群组前沿下水资源绿色效率TFP进行了收敛性检验。研究结论为：①东部地区技术落差比率高达1,而中西部地区仅为0.404和0.551,表明了中国东部地区水资源利用技术更接近共同前沿,而中西部地区水资源利用技术还有很大的提升空间,同时也证实了对水资源绿色效率进行划区研究的必要性;②群组前沿下水资源绿色效率更具合理性,更能真实地反应水资源绿色效率的变化情况;③从水资源绿色效率的空间重心转移路径可以看出,研究前期东部地区水资源绿色效率不断提升,而中西部地区则有所下降,研究后期在东西和南北2个方向上逐渐趋于失衡;④全国整体及中、西部地区水资源绿色效率TFP存在着σ收敛,且全国及东、中、西部地区均存在显著的绝对β收敛和条件β收敛,说明各地区水资源绿色效率的TFP差异会随着时间的推移收敛到各自的稳定状态。  相似文献   

基于 DEM 的荔枝冻害精细化区划--以福建省漳州市为例     

苏晓玲  陈志彪  陈志强  龚松柏  黄筱彧  郭湘宇  郭伟斌  朱艳 《亚热带资源与环境学报》2014,(3)

应用逐步回归分析方法和GIS技术,构建福建省越冬期极端最低气温（ Td ）和4个等级冻害指标（-2℃＜Td≤0℃、-3℃＜Td≤-2℃、-4℃＜Td≤-3℃、 Td ＜-4℃）发生频次空间分析模型,根据荔枝冻害评价指标,对漳州市荔枝种植区进行区划。结果表明：1）漳州市荔枝种植区可分为微冻害区、轻度冻害区、中度冻害区、重度冻害区,其中最微冻害区、轻度冻害区、划区结果与实际荔枝种植分布较吻合;2）漳州市荔枝种植微冻害区、轻度冻害区主要分布在漳州市东南部及西北部低山丘陵,中度冻害区、重度冻害区主要分布在适宜区以西海拔较高区域。  相似文献   

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潘国荣  吴廷  白昀 《大地测量与地球动力学》2014,34(4):102-105

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