A homogeneity-based feature selection algorithm for regionalization of watersheds     

《水文科学杂志》2012,57(2):269-280

ABSTRACT

An algorithm is proposed to find an appropriate selection of available watershed features for the regionalization of watersheds. Also, the algorithm is able to determine an appropriate number of regions for regional flood frequency analysis. The proposed algorithm is applied to data related to the Karun-e-Bozorg basin in the southwest of Iran. The results show that the proposed algorithm is efficient to find an appropriate selection of watershed features and an appropriate number of regions for regionalization, in the study area. It decreased the number of assessed regionalization states from 1020 to 252. In addition, applying the proposed algorithm mostly improved the accuracy of flood quantile estimates in the study area. The performance of the algorithm was evaluated through Monte Carlo simulation experiments. The results indicate that the efficiency of the algorithm increases by increasing the number of available watershed features.  相似文献   

江西地区有感地震史记     

邓辉  卢福水  陈家兴  毛华 《地震地磁观测与研究》2012,33(3):337-341

通过搜集江西省各地方史志地震记载,在前人研究基础上,给出江西省历史有感地震的筛选原则和确定方法,整理分析相应有感地震,并在中国有感地震目录中提取江西有感地震,删减重复部分,增补遗漏的史志有记载的有感地震,从而编辑江西地区相对完整的历史有感地震目录。  相似文献   

兰溪地磁台观测新址堪选     

王建国  刘永贵  张帆  唐志伟  杨毅  吴琼 《地震地磁观测与研究》2012,33(3):189-194

介绍浙江省兰溪地磁基准台场址堪选工作过程及计算结果,并介绍背景噪声和密跨度和跨度等常规测试过程,进行新址与杭州台记录数据之间的对比分析,通过科学计算和分析,确定新址取代旧址的科学性,为相似工作提供参考。  相似文献   

Record selection for aftershock incremental dynamic analysis          下载免费PDF全文

Katsuichiro Goda 《地震工程与结构动力学》2015,44(7):1157-1162

The back‐to‐back application of mainshock records as aftershock is often considered in conducting aftershock incremental dynamic analysis. In such an approach, the characteristics of mainshock records are considered to be similar to those of major aftershock records within the same mainshock–aftershock sequences. The underlying assumption is that the characteristics of selected mainshocks, other than those used for record selection, are not significant in the assessment of structural responses. A case study is set up to investigate the effects of aftershock record selection on the collapse vulnerability assessment. The numerical results for a specific wood‐frame structure indicate that the aftershock fragility can be affected by the aftershock record characteristics, particularly response spectral shape. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Ground motion selection for simulation‐based seismic hazard and structural reliability assessment          下载免费PDF全文

Brendon A. Bradley  Lynne S. Burks  Jack W. Baker 《地震工程与结构动力学》2015,44(13):2321-2340

This paper examines four methods by which ground motions can be selected for dynamic seismic response analyses of engineered systems when the underlying seismic hazard is quantified via ground motion simulation rather than empirical ground motion prediction equations. Even with simulation‐based seismic hazard, a ground motion selection process is still required in order to extract a small number of time series from the much larger set developed as part of the hazard calculation. Four specific methods are presented for ground motion selection from simulation‐based seismic hazard analyses, and pros and cons of each are discussed via a simple and reproducible illustrative example. One of the four methods (method 1 ‘direct analysis’) provides a ‘benchmark’ result (i.e., using all simulated ground motions), enabling the consistency of the other three more efficient selection methods to be addressed. Method 2 (‘stratified sampling’) is a relatively simple way to achieve a significant reduction in the number of ground motions required through selecting subsets of ground motions binned based on an intensity measure, IM. Method 3 (‘simple multiple stripes’) has the benefit of being consistent with conventional seismic assessment practice using as‐recorded ground motions, but both methods 2 and 3 are strongly dependent on the efficiency of the conditioning IM to predict the seismic responses of interest. Method 4 (‘generalized conditional intensity measure‐based selection’) is consistent with ‘advanced’ selection methods used for as‐recorded ground motions and selects subsets of ground motions based on multiple IMs, thus overcoming this limitation in methods 2 and 3. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

宾川地震信号发射台的选址、建设及初步观测结果   总被引：11，自引：0，他引：11  

王彬  吴国华  苏有锦  王宝善  葛洪魁  金明培  杨军  张启明  李涛 《地震研究》2015,38(1)

详细记述了宾川地震信号发射台的选址和建设过程,总结了多年来对台址所处区域的地震活动性、地震地质和地壳结构等的观测和研究结果,为今后主动源探测的研究和观测提供一些基础资料。此外,还介绍了发射台工作情况和取得的一些初步成果,并对今后的工作进行了思考。  相似文献   

德都地磁台迁建新址勘选结果分析     

张永刚  李娇  郝永梅  郭悦立  徐建权  吴海军 《防灾减灾学报》2015,(3):80-84

主要介绍了德都地磁台拟迁建新址的勘选过程及结果,勘选过程严格执行GB/T19531.2—2004《地震台站观测环境技术要求》(第二部分电磁观测)及DB/T9—2004《地震台站建设规范》(地磁台站)相关要求,并对勘选的结果做了初步分析。认为五大连池市和平镇翻身村南的台址符合地震及前兆数字观测技术规范的要求。  相似文献   

典型电厂海洋CO2地质储存场地选址适宜性评估   总被引：1，自引：0，他引：1  

刁玉杰  张森琦  李甫成  郜时旺  王晓龙  贾小丰 《吉林大学学报(地球科学版)》2016,46(3):844-854

我国华东和东部沿海地区分布有大量的火电、水泥和炼油等CO₂排放源,但由于距离陆域大中型沉积盆地较远,限制了规模化的深部咸水层CO₂地质储存工程选址。本文以华能玉环电厂为实例,开展了东海陆架盆地瓯江凹陷场地选址适宜性评估。通过瓯江凹陷CO₂地质储存地质条件分析,初步圈定出了发育有利储盖层的目标靶区,并依次开展了地质安全性和经济适宜性分析。利用碳封存领导人论坛潜力评估公式,计算了目标靶区推荐储层的单位面积储存潜力;并在构建综合储集条件、地质安全性条件和经济适宜性条件的指标体系基础上,开展了GIS多源信息叠加评估,在丽水西次凹内筛选出两处较好的场地。研究对开展该区海域CO₂地质储存选址具有一定的探索意义。  相似文献   

Seismic response analysis using characteristic ground motion records for risk‐based decision‐making (3R method)          下载免费PDF全文

Matjaž Dolšek  Marko Brozovič 《地震工程与结构动力学》2016,45(3):401-420

The concept of intensity‐based assessment for risk‐based decision‐making is introduced. It is realized by means of the so‐called 3R method (response analysis, record selection and risk‐based decision‐making), which can be used to check the adequacy of design of a new building or of the strengthening of an existing building by performing conventional pushover analysis and dynamic analysis for only a few ground motions, which are termed characteristic ground motions. Because the objective of the method is not a precise assessment of the seismic risk, a simple decision model for risk acceptability can be introduced. The engineer can decide that the reliability of a no‐collapse requirement is sufficient when collapse is observed in the case of less than half of, for example, seven characteristic ground motions. From the theoretical point of view, it is shown that the accuracy of the method is acceptable if the non‐linear response history analyses are performed at a low percentile of limit‐state intensity, which is also proven by means of several examples of multi‐storey reinforced concrete frame buildings. The 3R method represents a compromise between the exclusive use of either pushover analysis or dynamic analysis and can be easily introduced into building codes provided that its applicability is further investigated (e.g. asymmetric structures and other performance objectives) and that the procedure for the selection of characteristic ground motions is automated and readily available to engineers (www.smartengineering.si).  相似文献   

Code‐based record selection methods for seismic performance assessment of buildings          下载免费PDF全文

Miguel Araújo  Luís Macedo  Mário Marques  José Miguel Castro 《地震工程与结构动力学》2016,45(1):129-148

The recent concerns regarding the seismic safety of the existing building stock have highlighted the need for an improvement of current seismic assessment procedures. Alongside with the development of more advanced commercial software tools and computational capacities, nonlinear dynamic analysis is progressively becoming a common and preferable procedure in the seismic assessment of buildings. Besides the complexity associated with the formulation of the mathematical model, major issues arise related with the definition of the seismic action, which can lead to different levels of uncertainty in terms of local and global building response. Aiming to address this issue, a comparative study of different code‐based record selection methods proposed by Eurocode 8, ASCE41‐13 and NZS1170.5:2004 is presented herein. The various methods are employed in the seismic assessment of four steel buildings, designed according to different criteria, and the obtained results are compared and discussed. Special attention is devoted to the influence of the number of real ground motion records selected on the estimation of the mean seismic response and, importantly, to the efficiency that is achieved when an additional selection criteria, based on the control of the spectral mismatch of each individual record with respect to the reference response spectrum, is adopted. The sufficiency of the methods with respect to the pairs of M–R of the selected group of records and the robustness of the scaling procedure are also examined. The paper closes with a study which demonstrates the suitability of a simplified probability‐based approach recently proposed for estimating mean seismic demands. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献