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1.
Recent emergency flood situations at European rivers have revealed the demand for better and in-time information for citizens
in flood prone areas about flood development, as well as better coordination of resources and actions during pre-flood phases
and its critical stage. Information and Communication Technology (ICT) has a large potential to improve the situation. Decisions
may be supported by information about resources available at the region and national level, by information about means and
access to critical locations at the prevention as well as the evacuation phases, and by including citizens as well as managers
into one common information and communication process. The paper outlines the potential of ICT for these aspects. 相似文献
2.
An empirical model for investigating the behaviour of CaCO3 polymorphs incorporating a shell model for oxygen has been created. The model was constructed by fitting to: the structure of aragonite and calcite; their elastic, static and high-frequency dielectric constants; phonon frequencies at the wave vectors [&frac; 0 2] and [0 0 0] of calcite; and vibrational frequencies of the carbonate deformation modes of calcite. The high-pressure phase transition between calcite I and II is observed. The potentials for the CO3 group were transferred to other carbonates, by refitting the interaction between CO3 and the cation to both the experimental structures and their bulk modulus, creating a set of potentials for calculating the properties of a wide range of carbonate materials. Defect energies of substitutional cation defects were analyzed for calcite and aragonite phases. The results were rationalized by studying the structure of calcite and aragonite in greater detail. 相似文献
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A novel application of multi-criteria decision making (MCDM) technique to seismic soil liquefaction, a complex problem in earthquake geotechnical engineering, is presented. Seismic soil liquefaction depends on a diversified set of physical parameters with highly non-linear interconnections. Factors governing liquefaction may broadly be grouped as seismic parameters, site conditions and primarily dynamic soil properties, as the stimulus itself is manifestly dynamic. Each of these factors incorporates a wide range of variety of parameters that characterize liquefaction, to a varying degree of significance, such as: the magnitude, effective overburden pressure, shear modulus, normalized standard penetration blow count [N1]60, etc. Estimating rapid, yet accurate and reliable liquefaction susceptibility requires identification of the most significant factors controlling liquefaction. Thus a new concept of extracting significant parameters and gauging their importance is carried out by assigning them weights by applying MCDM introduced herein, whose evaluation is accomplished by means of an ‘entropy method’. In line with this, a relative reliability risk index (R3I) is computed indicating the ranking that directly reflects the severity of risk for liquefaction. Although the entropy analysis is carried out separately for the three multivariate criteria, it is remarkable that the R3I evaluated for each of these gives consistent ranking. 相似文献
5.
Decision-support systems for groundwater protection: innovative tools for resource management 总被引：1，自引：0，他引：1
Stefan Kollarits Gerhard Kuschnig Miran Veselic Ante Pavicic Corrado Soccorso Marina Aurighi 《Environmental Geology》2006,49(6):840-848
Governmental authorities are forced by law to make decisions within the framework of European, national and regional directives
in the fields of spatial planning, groundwater and environmental protection. These tasks can be supported by a decision-support
system, which integrates data from various sources and helps to make decision processes more effective and transparent. Basic
work for such a decision support system has been done in a transnational and interdisciplinary project (Interreg II C: KATER),
including metadata definition, metadata system, cartographic tools and GIS tools. The direct integration of these tools and
information in the decision process will be implemented in the next few years (project KATER II). 相似文献
6.
In 2005, a German research project was started to develop a novel approach to prove safety for a HLW repository in a salt formation, to refine the safety concept, to identify open scientific issues and to define necessary R&D work. This project aimed at identifying the key information for a HLW repository in salt. One important question is how this information may be best fulfilled by natural analogue studies. This question is answered by starting a review of the required key information needs of the safety case (post-closure phase) in order to assess whether or not these requirements can be supported by natural analogues information. In order to structure the review and to address the key elements of the safety concepts, three types of natural analogues are distinguished: (i) natural analogues for the integrity of the geological barrier, (ii) natural analogues for the integrity of the geotechnical barriers and (iii) natural analogues for release scenarios. For the safety case in salt type (i) and (ii) are of highest importance and are treated in this paper. The assessment documented in this paper on the one hand indicates the high potential benefit of natural analogues for a safety case in salt and on the other hand helps to focus the available human and financial resources for the safety case on the most safety-relevant aspects. 相似文献
7.
The paper describes an approach to the simulation of arbitrary laboratory tests with homogeneous stress and strain fields applicable to most constitutive models common in geomechanics. The method by Bardet and Choucair [Int. J. Numer. Anal. Meth. Geomech. 15(1):1–19, 1991] is generalized for an arbitrary number of controlling and controlled variables. The approach is illustrated for time‐dependent thermo–hydro–mechanical constitutive models. The purpose of the method is to define an endless variety of different laboratory tests declaratively by means of two matrices E and S , which define the constraints on the controlled quantities such as stress, strains, suction, or temperature. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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A procedure for partitioning bulk sediments into distinct grain-size fractions for geochemical analysis 总被引：1，自引：0，他引：1
A method to separate sediments into discrete size fractions for geochemical analysis has been tested. The procedures were chosen to minimize the destruction or formation of aggregates and involved gentle sieving and settling of wet samples. Freeze-drying and sonication pretreatments, known to influence aggregates, were used for comparison. Freeze-drying was found to increase the silt/clay ratio by an average of 180 percent compared to analysis of a wet sample that had been wet sieved only. Sonication of a wet sample decreased the silt/clay ratio by 51 percent. The concentrations of metals and organic carbon in the separated fractions changed depending on the pretreatment procedures in a manner consistent with the hypothesis that aggregates consist of fine-grained organic- and metal-rich particles. The coarse silt fraction of a freeze-dried sample contained 20–44 percent higher concentrations of Zn, Cu, and organic carbon than the coarse silt fraction of the wet sample. Sonication resulted in concentrations of these analytes that were 18–33 percent lower in the coarse silt fraction than found in the wet sample. Sonication increased the concentration of lead in the clay fraction by an average of 40 percent compared to an unsonicated sample. Understanding the magnitude of change caused by different analysis protocols is an aid in designing future studies that seek to interpret the spatial distribution of contaminated sediments and their transport mechanisms. 相似文献
11.
The National Tsunami Hazard Mitigation Program (NTHMP) Steering Committee consists of representatives from the National Oceanic and Atmospheric Administration (NOAA), the Federal Emergency Management Agency (FEMA), the U.S. Geological Survey (USGS), and the states of Alaska, California, Hawaii, Oregon, and Washington. The program addresses three major components: hazard assessment, warning guidance, and mitigation. The first two components, hazard assessment and warning guidance, are led by physical scientists who, using research and modeling methods, develop products that allow communities to identify their tsunami hazard areas and receive more accurate and timely warning information. The third component, mitigation, is led by the emergency managers who use their experience and networks to translate science and technology into user-friendly planning and education products. Mitigation activities focus on assisting federal, state, and local officials who must plan for and respond to disasters, and for the public that is deeply affected by the impacts of both the disaster and the pre-event planning efforts. The division between the three components softened as NTHMP scientists and emergency managers worked together to develop the best possible products for the users given the best available science, technology, and planning methods using available funds. 相似文献
12.
Robert Dela Vault 《Journal of Geochemical Exploration》1977,8(3):537-540
A simple and easy method for determining extractable copper in soils by spot testing is described. It uses an acetic acid/sodium acetate buffer to attack the sample and dithiooxamide (rubeanic acid) for reagent. The method can be employed on stream sediments, or on solutions obtained by a stronger attack. 相似文献
13.
本文主要阐述了利用Excel2003和CGIS结合计算村庄压煤储量的简便方法。这种方法较之以前原始的计算村庄压煤的方法很简便,节省了时间和人力、财力,可以说是十分行之有效的方法。 相似文献
14.
On hyperelasticity for clays 总被引：1，自引：0，他引：1
Under purely elastic conditions a constitutive model for clays should be conservative. This can be achieved by using a hyperelastic stress–strain relation derived from an elastic potential. To circumvent problems connected with formulation of a suitable potential a simple concept of back-stress elasticity is proposed. Several elastic models are critically reviewed, two of which had been originally incorrectly classified as hyperelastic. A novel elastic potential which can be used to generate various hyperelastic models is proposed. Its salient feature is that the resulting stiffness is a homogeneous function of order 1 with respect to stress. An example of Mathematica calculation with tensorial differentiation is enclosed (Wolfram S. Mathematica. A system for doing mathematics by computer. Addison-Wesley Publishing, 1988). © 相似文献
15.
V. E. Zharov M. V. Sazhin V. N. Sementsov K. V. Kuimov O. S. Sazhina N. T. Ashimbaeva 《Astronomy Reports》2010,54(2):112-120
Time series of the coordinates of radio sources defining the celestial coordinate frame are analyzed. Methods for selecting
such sources so as to enhance the stability of the frame are considered. Some of these sources, including so-called “defining”
sources, demonstrate significant proper motions. Since the stability of the celestial coordinate frame is determined by an
absence of global rotation relative to the defining sources (no net rotation), variation in their coordinates will lead to
a rotation of the axes of the celestial coordinate frame. The parameters of this rotation are calculated for two physical
models for the motions of extragalactic radio sources. The motions displayed by the first group of sources are linear and
uniform. Since the apparent speeds of radio sources are often close to, and sometimes exceed, the speed of light, it is supposed
that such radio sources have relativistic jets or plasma clouds that move with speeds roughly equal to the speed of light.
The observed uniform, linear motion can then be explained by precession of the jet. The second group of sources display non-linear
motions, interpreted as a manifestation of the acceleration of matter by the jet. It is assumed that a cloud of particles
that moves into the path of the jet is accelerated to relativistic speeds by the jet. A list of sources that should form a
very stable coordinate system for several decades into the future is composed based on these two models. 相似文献
16.
A. E. Lucas 《GeoJournal》1996,39(2):133-142
Geographic information systems can provide easy access to large quantities of geographically-referenced data for monitoring, planning and environmental decision support for coastal applications. The dynamic and variable nature of the coastal ocean environment gives rise to data issues different than those associated with land-based GIS. This paper investigates, in particular, the use of different data, including those produced by numerical simulations or ocean models, for coastal management and is illustrated with examples from a Baltic Sea GIS implementation. Implications for the use of these data in environmental management are discussed. 相似文献
17.
论不同构造煤类型煤层气开发 总被引：3，自引：0，他引：3
我国构造煤类型多,分布广泛,蕴含的煤层气资源量大,探明率低,开发难度大.本文在野外和实验室综合研究基础上,提出适合于煤层气资源开发的“描述+成因”的构造煤分类方案,按照固结类型将构造煤划分为未固结构造煤、固结构造煤两大类,及其对应的碎散煤、脆性煤和韧性煤3个系列,各种类型的构造煤依照形状或特殊结构构造进一步加以描述区分.不同类型的构造煤组合具有较明显的横向和垂向含气分带性特征,形成典型的构造非均质性煤层气藏.我国低煤阶构造煤和中高煤阶构造煤的发育情况与区域大地构造发生和演变具有相关性.构造煤煤层气开发更加强调系统论思想和配套技术集成开发,根据构造煤发育强度及赋存状态的差异,开发对象包括煤层、顶底板和夹矸(薄夹层)等含煤岩系;根据不同的开发对象,应有针对性地选用包括增温驱气等系统配套技术进行勘探开发. 相似文献
18.
Large-scale vulnerability assessments for natural hazards 总被引：3，自引：1，他引：2
This article examines the process by which vulnerability analysis takes place at the state level for State Hazard Mitigation
Plans, as required by the Disaster Mitigation Act of 2000. The methods developed by the Center for Hazards Research and Policy
Development at the University of Louisville are described, followed by a brief discussion on issues and challenges. A key
finding in this article is the need to understand the impact and role of vulnerability analysis on planning and policy-making
at the state and local level, as it applies to the investment of funding and resources in hazard mitigation. Recommendations
for policy as well as directions in future research are offered in conclusion. 相似文献
19.
岩土材料的强度往往表现出很强的各向异性,而已有的各向同性强度准则不能够描述这一特性。提出一个岩土材料的各向异性强度准则。为了描述材料的各向异性,引入了一个由应力张量和组构张量的联合不变量表达的各向异性参数。该参数可以描述加载方向和材料组构方向的夹角。强度准则是基于材料在子午面和偏平面上的破坏特性而建立的,这为描述广义的材料强度各向异性提供了方便。与原各向同性强度准则相比,各向异性强度准则只引入了两个新的模型参数,而且所有的模型参数都可以通过常规的室内试验结果确定。该准则的预测结果与砂土、黏土、天然黏土和岩石的试验结果比较表明,它能够很好地描述岩土材料强度的各向异性 相似文献
20.
Vitrinite reflectance on dispersed sedimentary organic matter is traditionally determined from histograms of vitrinite and inertinite reflectance measured on either whole rock samples or kerogen concentrates, or from particles usually in whole rock preparations chosen by morphology and relative reflectance to be first-cycle vitrinite. This paper discusses an alternative method: discrimination of first-cycle vitrinite using apparent maximum and minimum reflectance data plotted on reflectance crossplots. The use of crossplots increases the confidence that the macerals identified as first-cycle vitrinite are optically similar. The maximum–minimum data, in this study, were collected on a quantitative reflectance microscope outfitted with rotational polarization, a technique that eliminates the usual difficulty in collecting such data on very small macerals by stage rotation. 相似文献