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1.
关于2002年3月31日台湾M 7.5强震的临震预报 总被引：1，自引：0，他引：1
2002年3月31日，在台湾以东海中发生7.5级强烈地震。这次地震前，笔者在2002年3月21日分析预报中心预报部会商会上，明确提出临震预报意见：3月底前后台湾地区将发生6级左右地震，并上报到有关部门。这次地震虽然发生在我国台湾地区，但它是一次成功的临震预报的尝试。 相似文献
2.
MIKE BONELL 《水文科学杂志》2013,58(5):809-810
Abstract Since droughts are natural phenomena, their occurrence cannot be predicted with certainty and thus it must be treated as a random variable. Once drought duration and magnitude have been found objectively, it is possible to plan for the transport of water in known quantities to drought-stricken areas either from alternative water resources or from water stored during wet periods. The summation of deficits over a particular period is referred to as the drought magnitude. Drought intensity is the ratio of drought magnitude to its duration. These drought properties at different truncation levels provide significant hydrological and hydrometeorological design quantities. In this study, the run analysis and z-score are used for determining drought properties of given hydrological series. In addition, kriging is used as a spatial drought analysis for mapping. This study is applied to precipitation records for Istanbul, Edirne, Tekirdag and Kirklareli in the Trakya region, Turkey and then the drought period, magnitude and standardized precipitation index (SPI) values are presented to depict the relationships between drought duration and magnitude. 相似文献
3.
Delegates at the simultaneous National Astronomy Meeting, UK Solar Physics meeting and Spring MIST meeting were impressed by the warm welcome and efficient organization from the hosts, the University of Central Lancaster in Preston. The meetings were successful in terms of the number of participants and the breadth and depth of science discussed, but also in terms of the spread of that science across the media. 相似文献
4.
发震断层在其传播过程中与静止断层的交遇是地震时带有普遍性的现象,本文把交遇问题分为四种基本类型;建立各自相应的力学模型;通过物理力学分析和数学模拟,并结合地震实例讨论了各类交遇可能产生的后果: 1.发震断层终止于交遇处。2.发震断层被静止断层所截,而后,交遇区域发生强余震。3.发震断层穿越静止断层向前传播,而后,可能发生共轭地震。这些讨论可能对预测未来大震的震级及强余震的发生有一定的意义。 相似文献
5.
An Erratum has been published for this article in Earthquake Engng. Struct. Dyn. 2004; 33:1429. Based on structural dynamics theory, the modal pushover analysis (MPA) procedure retains the conceptual simplicity of current procedures with invariant force distribution, now common in structural engineering practice. The MPA procedure for estimating seismic demands is extended to unsymmetric‐plan buildings. In the MPA procedure, the seismic demand due to individual terms in the modal expansion of the effective earthquake forces is determined by non‐linear static analysis using the inertia force distribution for each mode, which for unsymmetric buildings includes two lateral forces and torque at each floor level. These ‘modal’ demands due to the first few terms of the modal expansion are then combined by the CQC rule to obtain an estimate of the total seismic demand for inelastic systems. When applied to elastic systems, the MPA procedure is equivalent to standard response spectrum analysis (RSA). The MPA estimates of seismic demand for torsionally‐stiff and torsionally‐flexible unsymmetric systems are shown to be similarly accurate as they are for the symmetric building; however, the results deteriorate for a torsionally‐similarly‐stiff unsymmetric‐plan system and the ground motion considered because (a) elastic modes are strongly coupled, and (b) roof displacement is underestimated by the CQC modal combination rule (which would also limit accuracy of RSA for linearly elastic systems). Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
6.
Earthquake engineering in China 总被引：2，自引：0，他引：2
胡聿贤 《地震工程与工程振动(英文版)》2002,1(1):1-9
The development of earthquake engineering in China is described into three stages. The initial stage in 1950’s – 1960’s was
marked with the initiation of this branch of science from its creation in the first national 12-year plan of science and technology
by specifying earthquake engineering as a branch item and IEM was one participant. The first earthquake zonation map and the
first seismic design code were soon completed and used in engineering design. Site effect on structural design and site selection
were seriously studied. The second stage marked with the occurrence of quite a few strong earthquakes in China, from which
many lessons were learned and corresponding considerations were specified in our design codes and followed in construction
practice. The third stage is a stage of disaster management, which is marked by a series of government documentations, leading
by a national law of the People’s Republic of China on the protecting against and mitigating earthquake disasters adopted
at the meeting of the Standing Committee of the National People’s Congress of the People’s Republic of China in 1997, and
then followed by some provincial and municipal laws to force the actions outlined in the national law. It may be expected
that our society will be much more safer to resist the attack of future strong earthquakes with less losses. Lastly, possible
future developments are also discussed. 相似文献
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8.
针对海啸危险性概率分析（PTHA）存在的较大不确定性问题,对不确定性产生来源进行了归纳和分类,提出了基于逻辑树与事件树方法合理量化不确定性的思路框架,并以马尼拉海啸潜源为研究对象,给出了量化震级上限、破裂面参数不确定的过程示例。数值模拟分析结果表明:海啸潜源震级上限的改变对危险性评估结果产生了显著影响,通过逻辑树方法可合理量化这种不确定性;地震破裂面的倾角、滑移角和破裂面积的随机不确定性对海啸危险性分析结果产生较为显著的影响,经事件树方法处理后的危险性结果保证率远高于20%,略低于80%,可基本满足工程抗海啸设计要求。 相似文献
9.
本文首先介绍１９９８年９月在意大利Ｔｒｉｅｓｔｅ召开的第二届国际重力委员会（ＩＧＣ）与国际大地水准面委员会（ＩＧｅＣ）联合大会的有关情况．然后根据大会报告的论文及交流的信息,对国际上物理大地测量若干领域的研究动态及发展趋势作简要论述．最后结合我国物理大地测量研究的有关状况提出思考和建议． 相似文献
10.
Jonathan Shanklin 《Astronomy& Geophysics》2003,44(5):5.31-5.32
There are many areas in which professional and amateur co-operation brings benefits to both. Speakers at the RAS-BAA Pro-am discussion meeting on 10 May explored observational work on some of the debris in the solar system. The meeting concluded with a lecture given in memory of the noted amateur astronomer George Alcock. Jonathan Shanklin reports. 相似文献
11.
《Journal of Atmospheric and Solar》2002,64(2):231-252
This review consists of questions to participants in the S-RAMP Symposium (S3) on CMEs and Coronal Holes, as well as to a few others, and their responses in a “town meeting” format (originally conducted on Hugh Hudson's website). Here we deal only with CMEs. The questions we ask aim at probing the weaknesses of existing models and highlighting controversies, thereby providing guidance toward a more complete view of solar eruptions. Topics covered include: the “solar flare myth”, flux ropes, new phenomena (EIT waves, dimmings, global brightenings), helicity and sigmoids, and transequatorial loops (as sources of CMEs). Although this is a review, we're more concerned here with what is not known than what is already agreed upon. We asked people to speculate freely in advance of the observational, analytical, and theoretical work that will provide definitive answers—this is not the standard Scientific Method at work! 相似文献
12.
The planning and management of water resources in the Shiyang River basin, China require a tool for assessing the impact of groundwater and stream use on water supply reliabilities and improving many environment‐related problems such as soil desertification induced by recent water‐related human activities. A coupled model, integrating rule‐based lumped surface water model and distributed three‐dimensional groundwater flow model, has been established to investigate surface water and groundwater management scenarios that may be designed to restore the deteriorated ecological environment of the downstream portion of the Shiyang River basin. More than 66% of the water level among 24 observation wells have simulation error less than 1·0 m. The overall trend of the temporal changes of simulated and observed surface runoff at the Caiqi gauging station remains almost the same. The calibration was considered satisfactory. Initial frameworks for water allocation, including agricultural water‐saving projects, water diversion within the basin and inter‐basin water transfer, reducing agricultural irrigation area and surface water use instead of groundwater exploitation at the downstream were figured out that would provide a rational use of water resources throughout the whole basin. Sixteen scenarios were modelled to find out the most appropriate management strategies. The results showed that in the two selected management options, the groundwater budget at the Minqin basin was about 1·4 × 108 m3/a and the ecological environment would be improved significantly, but the deficit existed at the Wuwei basin and the number was about 0·8 × 108 m3/a. Water demand for domestic, industry and urban green area would be met in the next 30 years, but the water shortage for meeting the demand of agricultural water use in the Shiyang River basin was about 2·2 × 108 m3/a. It is suggested that more inter‐basin water transfer should be required to obtain sustainable water resource use in the Shiyang River basin. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
13.
Emeka G. Nwoba Ashiwin Vadiveloo Christiana N. Ogbonna Benjamin E. Ubi James C. Ogbonna Navid R. Moheimani 《洁净——土壤、空气、水》2020,48(3)
The tremendous increase in human population and rapid decline in freshwater resources have necessitated the development of innovative and sustainable wastewater treatment methods. Africa as a developing continent is currently backing on sustainable solutions to tackle impending water resource crisis brought forward by wastewater‐induced environmental pollution and climate change. Microalgae‐based wastewater treatment systems represent an emerging technology that is capable of meeting the new demand for improved wastewater treatment and climate change mitigation strategies in an environmentally friendly manner. This review critically looks at the opportunities of Africa in harnessing and exploiting the potential of microalgae for the treatment of various wastewaters based on their capacity to recycle nutrients and for concurrent production of valuable biomass and several useful metabolites. Wastewaters, if improperly/completely untreated and discharged, simultaneously pollute freshwater sources and present significant health and environmental risks. Nutrients in wastewater can be utilized and recovered in the form of marketable biomass and products when integrated with the cultivation of microalgae. Several valuable bioproducts can be generated from wastewater‐grown microalgal biomass including biofuels, biofertilizers, animal feed, and various bioactive compounds. This biorefinery approach would most certainly improve wastewater treatment process economics, enhancing the technical feasibility of algae‐based wastewater remediation in African countries. 相似文献
14.
Edwin K. Schneider 《Annales Geophysicae》1996,14(3):336-341
A flaw is pointed out in the manner in which flux correction is currently applied to coupled atmosphere-ocean general circulation models. If a transient climate simulation were carried out using perfect initial data and a perfect model, then a perfect simulation would be made. However, if the model were flux corrected so that it is in equilibrium for current conditions, according to current practice, then errors in the simulation would grow initially to a finite amplitude and persist indefinitely. Larger errors would be produced by a simulation with the flux corrected model beginning from pre-industrial conditions than by a simulation beginning from current conditions. An example with a simple linear model is constructed to illustrate this point, and the relationship to the cold start problem is demonstrated. An optimal flux correction for the simple example is shown to be one which would eliminate the error in the current climate from a transient simulation begun sufficiently far in the past. 相似文献
15.
Environmental and ecological issues caused by water resources crisis have brought enormous challenges to the sustainable development of water-deficient area. Water resources allocation management balancing the relationship between the social-economic development and the ecological environment has become a hot topic in recent years. In this paper, an inexact fuzzy chance-constrained programming (IFCCP) approach is proposed for regional water resource allocation optimization with the aim of promoting the harmonious development of the social economic and the ecological environment, improving water utilization efficiency, and realizing water resources consumption control under uncertainties. The method is incorporated with interval parameter programming, fuzzy programming, and chance-constrained programming, for handling system uncertainties and balancing the optimal objectives with the risk of violating system constraints. Under this framework, an IFCCP model for water resources allocation management was successfully formulated and applied to a typical water-deficit area, Tianjin, China, for obtaining a better water resources plan among multiple users under resources and environmental limitation. Different total water consumption control policies are designed for assessing regional water allocation schemes. The results indicated that the gap of supply and demand will only be solved by foreign water, the transferred water from Luan River and Changjiang River would still be the main supplier in planning horizon. Moreover, the strict total water consumption control policy would guarantee the water requirement of ecological environment, lead to changes in the structure of water supply, actively guide on water conservation, and promote the large-scale utilization of desalted water and recycle water. 相似文献
16.
Remnant riparian vegetation,sediment and nutrient loads,and river rehabilitation in subtropical Australia 
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下载免费PDF全文 Jon Olley Joanne Burton Virgilio Hermoso Kate Smolders Joe McMahon Belinda Thomson Andrew Watkinson 《水文研究》2015,29(10):2290-2300
A decline in the ecosystem health of Australia's Moreton Bay, a Ramsar wetland of international significance, has been attributed to sediments and nutrients derived from catchment sources. To address this decline the regional management plan has set the target of reducing the loads by 50%. Reforestation of the channel network has been proposed as the means to achieve this reduction, but the extent of revegetation required is uncertain. Here we test the hypothesis that sediment and nutrient loads from catchments decrease proportionally with the increasing proportion of the stream length draining remnant vegetation. As part of a routine regional water quality monitoring program sediment and nutrient loads were measured in 186 flow events across 22 sub‐catchments with different proportions of remnant woodland. Using multiple linear regression analysis we develop a predictive model for pollutant loads. Of the attributes examined a combination of runoff and the proportion of the stream length draining remnant vegetation was the best predictor. The sediment yield per unit area from a catchment containing no remnant vegetation is predicted to be between 50 and 200 times that of a fully vegetated channel network; total phosphorus between 25 and 60 times; total nitrogen between 1.6 and 4.1 times. There are ~48 000 km of streams in the region of which 32% drain areas of remnant vegetation. Of these 17 095 km are above the region's water storage dams. We estimate that decreasing the sediment and phosphorus loads to Moreton Bay by 50% would involve rehabilitating ~6350 km of the channel network below the dams; halving the total nitrogen load would require almost complete restoration of the channel network. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
17.
Montjoly is a headland‐bound embayed sandy beach in Cayenne, French Guiana, that shows long‐term plan shape equilibrium in spite of periodic changes in accretion and erosion that alternately affect either end of the beach. These changes are caused by mud banks that move alongshore from the Amazon. The mechanisms involved in changes in the plan shape of the beach in response to the passage of one of these mud banks were monitored between 1997 and 2000 from airborne video imagery and field work. The beach longshore drift to the northwest, driven by the incident easterly to northeasterly swell usually affecting this coast, became temporarily reversed as the mud bank, migrating from east to west, initially sheltered the southeastern end of the beach. The difference in exposure to waves engendered a negative wave height gradient alongshore towards the southeast, resulting in the setting up of a cell circulation and counter‐active longshore drift from the exposed northwestern sector to the southeast. Sand eroded from the exposed sector accumulated first in the southeastern, and then the central sectors of the beach. The effect of increasing beach sheltering by the mudbank moving west is highlighted on the videographs by an ‘arrested’ pattern of beach shoreline development. The videographs show hardly any changes in beach plan shape since January 1999, due to sheltering of the beach from wave attack by the mud bank. It is expected that the eroded sector will recover in the future as the mud bank passes, leading to re‐establishment of the northwesterly sand drift. This temporally phased bi‐directional drift within the confines of the bounding headlands results in a rare example of mud‐bank‐induced beach rotation, and probably explains the long‐term equilibrium plan shape of Montjoly beach. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
18.
Sofia Grammatikou Michael N. Fardis Dionysis Biskinis 《Bulletin of Earthquake Engineering》2018,16(1):341-375
Cyclic tests of single concrete columns with smooth (plain) bars are not representative of building columns with lap splices at floor levels and story-long starter bars. Column specimens with fixity at top and bottom resemble building columns best, but few of those tested so far had smooth bars and even then without bar lap-splicing at floor level or FRP jackets at column ends. Empirical models based on single-column tests, especially the numerous ones with cantilever-type specimens, cannot be readily extended to columns with smooth bars in real-life buildings. Physical models of the Strut-and-Tie type are developed and are validated or calibrated through comparisons with laboratory tests. Their scope includes anchorage and splicing of bars with either 180° hooks or straight ends. Once validated, they are adapted to real-life multistory rectangular RC columns with smooth bars, in order to obtain the column properties of interest: the chord rotation at yielding and the cyclic ultimate chord rotation, with or without FRP jacketing. Different expressions apply to the top and bottom end of a column in a story, but a single one is used to estimate the column’s effective stiffness. Empirical alternatives fitted to the single-element test results have slightly less scatter than physical models, but caution is needed for their application to columns of real buildings. Simulations of the 3D seismic response of a plan wise asymmetric full size building, tested pseudo-dynamically before or after retrofitting all columns with FRPs or just two of them with RC jackets, provide certain confidence in the extension of the physical models for the estimation of the stiffness and ultimate deformation of columns with smooth bars in real-life buildings. 相似文献
19.
Professional conduct of scientists during volcanic crises 总被引：1，自引：0，他引：1
IAVCEI Subcommittee for Crisis Protocols: Chris Newhall · Shigeo Aramaki · Franco Barberi · Russell Blong · Marta Calvache · Jean-Louis Cheminee · Raymundo Punongbayan · Claus Siebe · Tom Simkin · Stephen Sparks · Wimpy Tjetjep Chris Newhall 《Bulletin of Volcanology》1999,60(5):323-334
Stress during volcanic crises is high, and any friction between scientists can distract seriously from both humanitarian and scientific effort. Friction can arise, for example, if team members do not share all of their data, if differences in scientific interpretation erupt into public controversy, or if one scientist begins work on a prime research topic while a colleague with longer-standing investment is still busy with public safety work. Some problems arise within existing scientific teams; others are brought on by visiting scientists. Friction can also arise between volcanologists and public officials. Two general measures may avert or reduce friction: (a) National volcanologic surveys and other scientific groups that advise civil authorities in times of volcanic crisis should prepare, in advance of crises, a written plan that details crisis team policies, procedures, leadership and other roles of team members, and other matters pertinent to crisis conduct. A copy of this plan should be given to all current and prospective team members. (b) Each participant in a crisis team should examine his or her own actions and contribution to the crisis effort. A personal checklist is provided to aid this examination. Questions fall generally in two categories: Are my presence and actions for the public good? Are my words and actions collegial, i.e., courteous, respectful, and fair? Numerous specific solutions to common crisis problems are also offered. Among these suggestions are: (a) choose scientific team leaders primarily for their leadership skills; (b) speak publicly with a single scientific voice, especially when forecasts, warnings, or scientific disagreements are involved; (c) if you are a would-be visitor, inquire from the primary scientific team whether your help would be welcomed, and, in general, proceed only if the reply is genuinely positive; (d) in publications, personnel evaluations, and funding, reward rather than discourage teamwork. Models are available from the fields of particle physics and human genetics, among others. 相似文献
20.
C. Chen G. H. Huang Y. P. Li Y. Zhou 《Stochastic Environmental Research and Risk Assessment (SERRA)》2013,27(3):713-723
A robust risk analysis method (RRAM) is developed for water resource decision making under uncertainty. This method incorporates interval-parameter programming and robust optimization within a stochastic programming framework. In the RRAM formulation, penalties are exercised with the recourse against any infeasibility, and robustness measures are introduced to examine the variability of the second stage costs which are above the expected levels. In this study, a number of weighting levels are considered which correspond to the robustness levels of risk control. Generally, a plan with a higher robust level would better resist from system risk. Thus, decision with a lower robust level can correspond to a higher risk of system failure. There is a tradeoff between system cost and system reliability. The RRAM is applied to a case of water resource management. The modeling results can help generate desired decision alternatives that will be particularly useful for risk-aversive decision makers in handling high-variability conditions. The results provide opportunities to managers to make decisions based on their own preferences on system stability and economy, and ensure that the management policies and plans be made with reasonable consideration of both system cost and risk. 相似文献