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1.
Following the catastrophic and devastating Atlantic Hurricane seasons in 2004 and 2005, there has been increased interest in formulating planning directives and policy aimed at minimizing the societal impacts of future storms. Not all populations will evacuate an area forecast to be affected by a hurricane, so emergency managers must plan for these people who remain behind. Such planning includes making food, water, ice, and other provisions available at strategic locations throughout an affected area. Recent research has tackled problems related to humanitarian and relief goods distribution with respect to hurricanes. Experience shows that the torrential rains and heavy winds associated with hurricanes can severely damage transportation network infrastructure rendering it unusable. Scanning the literature on hurricane disaster relief provision, there are no studies that expressly consider the potential damage that may be caused to a transportation network by strong storms. This paper examines the impacts of simulated network failures on hurricane disaster relief planning strategies, using a smaller Florida City as an example. A relief distribution protocol is assumed where goods distribution points are set up in pre-determined locations following the passage of a storm. Simulation results reveal that modest disruptions to the transportation network produce marked changes in the number and spatial configuration of relief facilities. At the same time, the transportation network appears to be robust and is able to support relief service provision even at elevated levels of hypothesized disruption.  相似文献   

2.
Yeh  Chao-Hsien  Chen  Yi-Ru 《Natural Hazards》2020,103(1):317-327

The continuously low efficiencies of flood relief service in responding to flooding disasters in Taiwan highlight a need for research. This service efficiency is negatively influenced by flood relief facility locations and their operational management structure. The Fazih River floodplain has been previously identified as a high-flood-risk area using an analytic hierarchy process. The purpose of this study is to use the location set covering problem and the maximal covering location problem to determine the number of relief facilities required and the maximum covering area of each facility for the case study area of the Fazih River floodplain. The findings showed that covering distances range from 3.0 to 6.6 km and the number of facilities required for improved service efficiency is between 1 and 4.

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3.
This work developed models to identify optimal spatial distribution of emergency evacuation centers(EECs) such as schools, colleges, hospitals, and fire stations to improve flood emergency planning in the Sylhet region of northeastern Bangladesh.The use of location-allocation models(LAMs) for evacuation in regard to flood victims is essential to minimize disaster risk.In the first step, flood susceptibility maps were developed using machine learning models(MLMs), including: Levenberg–Marquardt back propagation(LM-BP) neural network and decision trees(DT) and multi-criteria decision making(MCDM) method.Performance of the MLMs and MCDM techniques were assessed considering the area under the receiver operating characteristic(AUROC) curve.Mathematical approaches in a geographic information system(GIS) for four well-known LAM problems affecting emergency rescue time are proposed: maximal covering location problem(MCLP), the maximize attendance(MA), p-median problem(PMP), and the location set covering problem(LSCP).The results showed that existing EECs were not optimally distributed, and that some areas were not adequately served by EECs(i.e., not all demand points could be reached within a 60-min travel time).We concluded that the proposed models can be used to improve planning of the distribution of EECs, and that application of the models could contribute to reducing human casualties, property losses, and improve emergency operation.  相似文献   

4.
蒋臻蔚  彭建兵  王启耀 《岩土力学》2010,31(Z2):317-321
地铁3号线是西安市轨道交通线网中西南至东北方向的主骨架线,由于西安市特殊的地质环境,工程建设中会遇到地面沉降和地裂缝等不良地质问题,因此,必须在工程建设前对3号线沿线地面沉降和地裂缝的发生原因、分布范围及发展趋势仔细进行研究。通过对地铁3号线沿线的实地踏勘,对前人研究资料的收集与分析认为,地铁3号线涉及了辛家庙、胡家庙、金花南路、观音庙、小寨5个老沉降中心和高新区、曲江新区2个新沉降中心,老沉降中心及曲江沉降中心目前沉降速率均较低,危险性小,新沉降中心鱼化寨目前地面沉降速率较大,危险性中等;地铁3号线与7条地裂缝在12个地段相交,其中危险性大的有6处,危险性中等的有5处,危险性小的有1处,要特别注意从吉祥村到小寨段与f7地裂缝的相交段。根据地面沉降和地裂缝对地铁工程影响的特点,提出了相应的防治措施。文中研究成果对西安地铁建设具有很好的参考价 值。  相似文献   

5.
基于矿产资源空间位置的研究方法对勘探找矿具有重要意义。设计开发了基于空间位置关联分析和预测方法,该方法根据隐伏矿体预测的相似-类比理论,通过分析已公开的矿产资源空间分布数据,获取已知矿种的相关性,进一步对隐伏矿体进行分析和预测。以我国西部部分地区的矿产资源空间分布数据为样本,采用Apriori算法分析已知矿种空间位置上的关联关系,通过分析得出该区域矿种的共生和伴生等关联关系,获得隐伏矿体的预测结果。通过与现有成果对比证明该方法的有效性和可行性,利用GoogleEarth等可视化的工具进行预测结果展现,以便更好地进行对比研究。研究的创新点在于设计开发了基于空间位置关联分析和预测方法,利用该方法对已知矿种空间位置进行关联分析,推导出所在区域矿种的共生和伴生等关系,对隐伏矿体进行了分析预测。  相似文献   

6.
A numerical experiment was carried out to test whether the patchy CO2 emission patterns observed at the Zero Emissions Research and Technology release facility are caused by the presence of packers that divide the horizontal injection well into six CO2-injection zones. A three-dimensional model of the horizontal well and cobble–soil system was developed and simulations using TOUGH2/EOS7CA were carried out. Simulation results show patchy emissions for the seven-packer (six-injection-zone) configuration of the field test. Numerical experiments were then conducted for the cases of 24 packers (23 injection zones) and an effectively infinite number of packers. The time to surface breakthrough and the number of patches increased as the number of packers increased suggesting that packers and associated along-pipe flow are the origin of the patchy emissions. In addition, it was observed that early breakthrough occurs at locations where the horizontal well pipe is shallow and installed mostly in soil rather than the deeper cobble. In the cases where the pipe is installed at shallow depths and directly in the soil, higher pipe gas saturations occur than where the pipe is installed slightly deeper in the cobble. It is believed this is an effect mostly relevant to the model rather than the field system and arises through the influence of capillarity, permeability, and pipe elevation of the soil compared to the cobble adjacent to the pipe.  相似文献   

7.
利用人工神经网络方法检测地震剖面同相轴   总被引:1,自引:1,他引:0  
在地震勘探中,经过各种处理后最终得到用于解释的地震剖面实际上都可以看作是一些图像。这样,就可以从图像处理的观点来看问题,图像的特征有边缘和区域,那么,地震反射同相轴在地震剖面图像上,可以看作是一边缘。人工神经网络是近年来发展起来的一种新技术,它可以进行二维图像的边缘检测,基于这一点,把神经网络边缘检测技术应用到地震剖面上来检测地震反射界面,压制地震剖面上的随机干扰,从而改善地震图像的质量,达到提高地震资料信噪比和分辨率的目的。运用该技术对实际剖面进行了处理,效果很好,证明了方法的可行性和有效性。  相似文献   

8.
In the traditional method of earthquake loss estimation, all exposed facilities are classified according to their structural type and/or occupancy. Inventory data is collected and the total loss is estimated as the aggregate of all facility losses from each facility class separately. For many regions of the world, however, the vast amount of data required for this method is difficult or impossible to obtain. The traditional method is also unable to estimate quickly the loss from an unexpected catastrophic earthquake. It is difficult to give the necessary risk information to help the government with rescue and relief after the earthquake disaster.In this paper, we propose a quick and approximate estimation method of earthquake loss based on a macroscopic index of exposure and population distribution from GIS. This method was applied to analyze several earthquake scenarios with World Bank and CIESIN data. The preliminary analysis and comparison results show that our method is effective and reasonable for quick assessment of earthquake risk.  相似文献   

9.
Mukherjee  Kasturi  Mondal  Debika 《GeoJournal》2022,87(4):931-949

Spatial equity in urban facilities or service distribution is considered as a critical determinant of the quality of urbanization. Spatial equity simply means the presence of adequate facilities and equal proximity. Many initiatives have mostly focused on one type of facility, obviating the holistic understanding of the equity of distribution of all basic facilities in cities. Moreover, the perceptions of the citizens in the process of planning are hardly considered. In this paper, an integrated facility-satisfaction index is presented to evaluate the balance between the distribution of facilities and the level of residents' satisfaction derived from those facilities. This method has taken all possible urban facilities and categorized them as educational, health, financial, recreation, and others. The per capita facility availability is calculated by incorporating the spatial distribution of urban facilities, the service range of facilities, population distribution, and weight. The proper weights have been given by employing the analytical hierarchy process (AHP). The satisfaction index has been derived from the citizens’ perception of each facility, marked on a 5-point Likert scale during the field survey. The paired-sample t-test demonstrated that there is a significant difference between the facility availability and satisfaction index at the significance level of 0.05. The application of the method is demonstrated in fast urbanizing Barasat city, West Bengal, India. Based on the degree of facility-satisfaction differences or correspondences, the entire region has been categorized into four zones viz. satisfied people with favorable facility availability, unsatisfied people with poor facility availability, unsatisfied people with relatively high facility availability, and satisfied people with relatively low facility availability. The pattern has been validated by identifying spatial clusters and spatial outliers of facility availability and satisfaction using local Moran’s I. This approach can help a city to distribute the facilities to satisfy the citizens of all corners which will help to overcome the constant problems of policy decisions without adequate and reliable information about the actual demand of the residents.

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10.
In Iran, earthquakes cause enormous damage to the people and economy. If there is a proper estimation of human losses in an earthquake disaster, it could be appropriately responded and its impacts and losses will be decreased. Neural networks can be trained to solve problems involving imprecise and highly complex nonlinear data. Based on the different earthquake scenarios and diverse kind of constructions, it is difficult to estimate the number of injured people. With respect to neural network’s capabilities, this paper describes a back propagation neural network method for modeling and estimating the severity and distribution of human loss as a function of building damage in the earthquake disaster. Bam earthquake data in 2003 were used to train this neural network. The final results demonstrate that this neural network model can reveal much more accurate estimation of fatalities and injuries for different earthquakes in Iran and it can provide the necessary information required to develop realistic mitigation policies, especially in rescue operation.  相似文献   

11.
Pyrrhotite (Fe7S8) is a natural iron sulphide that can participate in rock magnetisation. Its electronic structure is not yet surely described. X-ray magnetic circular dichroism (XMCD) at Fe L2,3 edges on Fe7S8, coupled with multiplet calculations, shows that iron is present only as Fe2+ in this magnetic iron sulphide. It reveals a strong magnetic orbital moment. XMCD at Fe and S K edges shows the quite strong polarization of both Fe and S in Fe7S8.  相似文献   

12.
DNAPLs本身的化学性质、裂隙的几何性质以及泄漏条件等影响重非水相流体(DNAPLs)在裂隙介质中的运移和分布。针对DNAPLs的运移规律研究多集中在孔隙介质和单裂隙中,在随机网络裂隙中的研究较少。本研究生成随机网络裂隙是基于蒙特卡罗方法,运用像素扫描识别并输出裂隙的坐标和宽度,然后采用PetraSim模拟四氯乙烯(PCE)在随机网络裂隙中的运移,探讨裂隙宽度空间变异性和泄漏条件(包括泄漏速率和泄漏位置)对DNAPLs运移的影响。数值模拟结果表明:DNAPLs的空间展布和运移路径受裂隙宽度空间变异性影响,随着网络裂隙中裂隙宽度空间变异性增大,出现优势通道,DNAPLs运移的速率加快,DNAPLs的质心位置和饱和度空间分布发生明显变化;DNAPLs的运移速率和空间展布受泄漏速率影响,泄漏速率越大,DNAPLs运移速率越快,模型底部蓄积的DNAPLs的饱和度越大,DNAPLs的空间展布也越大;同一网络裂隙中,泄漏位置不同,导致DNAPLs的运移路径及分布范围不同,不同的泄漏位置重力方向裂隙空间变异性不同,导致DNAPLs运移路径和空间展布各不相同。研究结果可以丰富裂隙介质中DNAPLs运移机理研究,为裂隙介质中DNAPLs污染修复提供模型参考。  相似文献   

13.
Voronoi, or area-of-influence, polygons are convex, space-filling polygons constructed around a set of points (Voronoi centers) such that each polygon contains all points closer to its Voronoi center than to the center of any other polygon. The relationship of Voronoi centers to edges of Voronoi polygons is used to test whether any convex tessellation consists of Voronoi polygons. This test amounts to finding Voronoi centers that best fit the given tessellation. Voronoi centers are found by solving two systems of linear equations. These equations represent (1) conditions on the slope of polygon edges relative to the slope of lines through Voronoi centers, and (2) conditions on the distance from edges to Voronoi centers. Least squares and constrained least-squares solutions are used to solve the two systems. Different methods of solution can provide insight as to how a tessellation varies from Voronoi polygons. A goodness-of-fit statistic is derived and examined by testing randomly generated convex tessellations. Some polygonal ice cracks provide an example of naturally occurring polygons that are approximated closely by Voronoi polygons.  相似文献   

14.
CO2 is now considered as a novel heat transmission fluid to extract geothermal energy. It can achieve the goal of energy exploitation and CO2 geological sequestration. Taking Zhacanggou as research area, a “Three-spot” well pattern (one injection with two production), “wellbore–reservoir” coupled model is built, and a constant injection rate is set up. A fully coupled wellbore–reservoir simulator—T2Well—is introduced to study the flow mechanism of CO2 working as heat transmission fluid, the variance pattern of each physical field, the influence of CO2 injection rate on heat extraction and the potential and sustainability of heat resource in Guide region. The density profile variance resulting from temperature differences of two wells can help the system achieve “self-circulation” by siphon phenomenon, which is more significant in higher injection rate cases. The density of CO2 is under the effect of both pressure and temperature; moreover, it has a counter effect on temperature and pressure. The feedback makes the flow process in wellbore more complex. In low injection rate scenarios, the temperature has a dominating impact on the fluid density, while in high rate scenario, pressure plays a more important role. In most scenarios, it basically keeps stable during 30-year operation. The decline of production temperature is <5 °C. However, for some high injection rate cases (75 and 100 kg/s), due to the heat depletion in reservoir, there is a dramatic decline for production temperature and heat extraction rate. Therefore, a 50-kg/s CO2 injection rate is more suitable for “Three-spot” well pattern in Guide region.  相似文献   

15.
Disasters resulting from climate change are shown to be important determinants of people’s life choice decisions. In the literature, travel behavior choice and life choices are usually addressed separately under disasters such as flood and cyclone. However, travel behavior may be interdependent with other life choices, jointly shaping people’s adaptation decisions. To this end, the paper advances the literature by exploring the interrelationship between changes in travel behavior and job and residential location under flood disasters, while separating coastal and inland observations. For this purpose, a stated preference survey was conducted in 14 cities of Bangladesh in early 2013. An analysis approach based on structural equation modeling was developed to investigate the correlations between travel behavior change and job and residential location changes. Model estimation results suggest that flood impacts have significant influences on inland people’s life choices, while coastal people’s life choices are mainly affected by flood adaptation responses and attitudes. Significant correlations between travel behavior change and job and residential location changes are found for both observations. Moreover, both coastal and inland people tend not to change residential locations if changes in job location and travel behavior are made. Inland people may not change travel behavior if their job and/or residential locations are changed, but coastal people’s job and residential location changes are associated with changes in travel behavior. Travel behavior change is found to have more of an effect on residential location change than job location change in both regions. These findings conclude that the two-way relationship between travel behavior and life choices should be taken into account in future analyses, and thus adaptation policies to climate change disasters could be better linked with people’s behavioral responses.  相似文献   

16.
Iturrizaga Lasafam 《GeoJournal》1997,42(2-3):303-328
This article presents observations on the natural hazard potential for permanent and seasonal mountain settlements and infrastructure such as routeways and irrigation canals in the North-West Karakorum. The remote high mountain settlement Shimshal (3080 m), located in the upper Shimshal valley and surrounded by three potential natural glacier dams, is of particular interest. The permanent settlement of Shimshal and its seasonal pasture settlements in the Shimshal Pamir at heights of 3200 and 4600 m respectively, reach the upper limits for permanent and temporary settlement. The choice of location for settlement and agricultural activities is already dictated by relief conditions. Primary settlement areas are the sediment accumulations in the valley floors. The wide distribution of unconsolidated screes in particular prevents settlement expansion upwards along the valley slopes. Glacial outburst floods as well as seasonal flooding events further reduce the scanty settlement area, as well as being among the most devastating sources of danger. The production of debris and the supply of loose material deposits induced in connection with the glaciation history of the area becomes a permanent source of danger for human settlement through resedimentation in the form of rockfall or mudflow. Furthermore, canal systems essential for the survival of oasis settlements suffer annual destruction through mass movements on the slopes, induced by the glacially pre-formed relief. Thus the adaptation of settlement locations to a glacially formed mountain relief will be examined in this study, with particular reference to the geomorphological landscape situation. What makes the Shimshal settlement particularly interesting is its very isolated location at a distance of 80 km from the Hunza valley which contains the main settlement concentration of the North-West Karakorum. Traditional ways of life can be expected to be well protected from outside influences. In the North-West Karakorum we find a debris landscape which differs greatly in its development and distribution from that of the Himalayas, influenced particularly in the lower valley locations between 1000 and 3000 m by the different climatic situation, and where therefore in comparison with the Himalayas a completely different pattern of natural hazards arises.  相似文献   

17.
Petrological and experimental studies demonstrated that nepheline-normative, SiO2-rich melts can be present in the upper mantle at pressures 1.5 GPa. To evaluate the role of such melts in mantle processes and magma genesis, we carried out two types of experiments: (1) melt distribution experiments to characterize the grain-scale distribution of a small fraction of typical SiO2-rich mantle melt (SRMM) in polycrystalline olivine (Ol) at 1,180°C, 1.2 GPa; and (2) an infiltration experiment to test the ability of SRMM to impregnate and metasomatise neighbouring non-molten mantle rocks. The median dihedral angles at Ol-Ol-SRMM contacts are equal to 50°, implying that melt should be interconnected at all melt fractions. Complications arise, however, in the investigated system because Ol–liquid interfacial energy is anisotropic, and we estimate that the connectivity threshold in the SRMM–Ol system is 0.3 vol%. Regarding the very low volume fraction of SRMM in peridotites, we conclude that these melts either occur as isolated pockets or form a network of grain edge channels with a low degree of connectivity due to a large number of dry grain edges. Even in the case where an interconnected network exists, their large viscosities should prohibit the extraction of SRMM from peridotite sources. The infiltration experiment also points to a very reduced mobility of SRMM in the upper mantle. In this experiment, a slice of synthetic dunite was immersed into a magma reservoir made of 60 wt% SRMM+40 wt% Ol, and subjected to 1,180°C-1.2 GPa for 113 h: despite this long duration, the SiO2-rich liquid was unable to infiltrate measurably the dunite. Our experiments do not support the hypothesis that SRMM represent agents of mantle metasomatism.  相似文献   

18.
This paper explores spatial changes to knowledge transfer by Canadian and American corporate networks from 1976 to 1996. Results support facets of a World Cities approach for Canada. Toronto lies at the top of the hierarchy, while Montreal, Calgary, and Vancouver fall into a third tier of specialized regional cities. The American knowledge network also possesses facets of the world cities approach. The world city, New York, lies at the top of the hierarchy. Further down, Chicago is a specialized national city, while a number of regional centers have emerged to play a larger role over the twenty-year study period. A third tier of cities has emerged to play the critical role of specialized regional cities. This geographical phenomenon can be explained in terms of industry, headquarters locations, and network maturity. Finance, insurance and real estate, as well as “other manufacturing” are three sectors of the economy that are prominent in the network. In Canada, these sectors have increasingly centralized in Toronto while decentralizing in the United States. Similarly, the headquarters location of American firms is decentralizing from New York and Chicago, while Canadian headquarters continue to be centralized in Toronto. Finally, results indicate that the potential for knowledge transfer depends upon maturity of the system under investigation. The mature US network with a large pool of qualified business individuals is better suited for knowledge transfer at the regional level. The Canadian network is less developed and not appropriate for regional systems of knowledge transfer. The result is a Canadian corporate knowledge threshold that encompasses the entire country while a number of much smaller corporate knowledge thresholds appear across the United States.  相似文献   

19.
Conclusions In general terms, this paper has demonstrated how the expansion of public facilities can be phased and implemented within the framework of certain policy objectives. Given an existing network of hospitals, for instance, it is possible to plan and implement the provision of additional facilities in a manner that enhances the spatial efficiency of the expanded network. The expansion can be executed in such a way that with the addition of each new facility, not only is aggregate travel minimized, but also a specified proportion of the population can be brought within easy reach of hospital services. This method is a particularly useful one because in planning the location of facilities, authorities hardly ever start off with a clean slate. Usually some facilities of the same kind might already be occupying some locations which may or may not be optimal. But whether or not the already existing network is optimal, the overall efficiency of the expanded network can be enhanced by proceeding in the manner outlined above.This method can be applied to a wide range of public facilities, like schools for instance. But its application depends, among other things, on the clear definition of locational and policy objectives. Different objectives could produce different locational patterns. Even variations in the measures of distance used can produce different locational patterns.  相似文献   

20.
Adsorption of H2O, NH3 and C6H6 on H- and alkali metal-exchanged structures of mordenite and on corresponding cations on the smectite layer is investigated by ab initio density-functional calculations. Proton or an alkali metal cation compensates one Al/Si framework substitution and resides in the extra-framework position of zeolite or above flat smectite layer close to the Al/Si substitution. Pronounced similarities between zeolite and smectite are observed in changes of the adsorption energies and location of the external cation with changing character of the external cation. Calculated adsorption energies exhibit the following trend: E(NH3) > E(H2O) > E(C6H6). Because of looser contact with the framework, zeolitic cations are stronger adsorption centers and calculated adsorption energies of zeolites are by ~20–30% larger than cations of smectites. The highest adsorption energy is calculated for H-exchanged structures and down the group of alkali metal cations a decrease of the adsorption energy is observed. Deviations from the smooth variation of the adsorption energy are caused by: (1) formation of strong hydrogen bonds in H-exchanged structures, (2) adsorption induced migration of the external Li+ cation, and (3) steric hindrances of the flat C6H6 molecule adsorbed on the cation in the cage of zeolite.  相似文献   

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