共查询到20条相似文献，搜索用时 15 毫秒
1.
Large-scale damage to the power infrastructure from hurricanes and high-wind events can have devastating ripple effects on infrastructure, the broader economy, households, communities, and regions. Using Hurricane Irma’s impact on Florida as a case study, we examined: (1) differences in electric power outages and restoration rates between urban and rural counties; (2) the duration of electric power outages in counties exposed to tropical storm force winds versus hurricane Category 1 force winds; and (3) the relationship between the duration of power outage and socioeconomic vulnerability. We used power outage data for the period September 9, 2017–September 29, 2017. At the peak of the power outages following Hurricane Irma, over 36% of all accounts in Florida were without electricity. We found that the rural counties, predominantly served by rural electric cooperatives and municipally owned utilities, experienced longer power outages and much slower and uneven restoration times. Results of three spatial lag models show that large percentages of customers served by rural electric cooperatives and municipally owned utilities were a strong predictor of the duration of extended power outages. There was also a strong positive association across all three models between power outage duration and urban/rural county designation. Finally, there is positive spatial dependence between power outages and several social vulnerability indicators. Three socioeconomic variables found to be statistically significant highlight three different aspects of vulnerability to power outages: minority groups, population with sensory, physical and mental disability, and economic vulnerability expressed as unemployment rate. The findings from our study have broader planning and policy relevance beyond our case study area, and highlight the need for additional research to deepen our understanding of how power restoration after hurricanes contributes to and is impacted by the socioeconomic vulnerabilities of communities. 相似文献
2.
Hurricanes can severely damage the electric power system, and therefore, predicting the potential impact of an approaching
hurricane is of importance for facilitating planning and storm-response activities. A data mining approach, classification
and regression trees (CART), was employed to evaluate whether the inclusion of soil and topographic variables improved the
predictive accuracy of the power outage models. A total of 37 soil variables and 20 topographic variables were evaluated in
addition to hurricane, power system, and environmental variables. Hurricane variables, specifically the maximum wind gust
and duration of strong winds, were the most important variables for predicting power outages in all models. Although the inclusion
of soil and topographic variables did not significantly improve the overall accuracy of outage predictions, soil type and
soil texture are useful predictors of hurricane-related power outages. Both of these variables provide information about the
soil stability which, in turn, influences the likelihood of poles remaining upright and trees being uprooted. CART was also
used to evaluate whether environmental variables can be used instead of power system variables. Our results demonstrated that
certain land cover variables (e.g., LC21, LC22, and LC23) are reasonable proxies for the power system and can be used in a
CART model, with only a minor decrease in predictive accuracy, when detailed information about the power system is not available.
Therefore, CART-based power outage models can be developed in regions where detailed information on the power system is not
available. 相似文献
3.
Local policies can play an important role in establishing a context that shapes vulnerability and influences subsequent recovery
of lifelines under the natural hazards of extreme wind and seismic events. External factors, such as access availability,
have long been known to influence the rate of restoration of utility systems following blackouts. Thus, since system performance
takes place within a socio-technical-political context, it can be anticipated that selected local policies may also influence
either the geographic extent of damage or the rate of restoration or both. This project empirically validates the assumption
that selected local non-design policies establish a context that significantly (measurably) influences system functionality
in terms of spatial extent and duration of outage. 相似文献
4.
Mehmet Baran Ulak Ayberk Kocatepe Lalitha Madhavi Konila Sriram Eren Erman Ozguven Reza Arghandeh 《Natural Hazards》2018,92(3):1489-1508
Natural disasters have devastating effects on the infrastructure and disrupt every aspect of daily life in the regions they hit. To alleviate problems caused by these disasters, first an impact assessment is needed. As such, this paper focuses on a two-step methodology to identify the impact of Hurricane Hermine on the City of Tallahassee, the capital of Florida. The regional and socioeconomic variations in the Hermine’s impact were studied via spatially and statistically analyzing power outages. First step includes a spatial analysis to illustrate the magnitude of customers affected by power outages together with a clustering analysis. This step aims to determine whether the customers affected from outages are clustered or not. Second step involves a Bayesian spatial autoregressive model in order to identify the effects of several demographic-, socioeconomic-, and transportation-related variables on the magnitude of customers affected by power outages. Results showed that customers affected by outages are spatially clustered at particular regions rather than being dispersed. This indicates the need to pinpoint such vulnerable locations and develop strategies to reduce hurricane-induced disruptions. Furthermore, the increase in the magnitude of affected customers was found to be associated with several variables such as the power network and total generated trips as well as the demographic factors. The information gained from the findings of this study can assist emergency officials in identifying critical and/or less resilient regions, and determining those demographic and socioeconomic groups which were relatively more affected by the consequences of hurricanes than others. 相似文献
5.
Stephanie E. Chang Timothy L. McDaniels Joey Mikawoz Krista Peterson 《Natural Hazards》2007,41(2):337-358
This paper addresses the problem of interdependent failures of critical infrastructures in disasters. Disruptions to critical
infrastructure systems such as electric power or transportation frequently cause major social and economic loss in disasters,
both directly and through failures in one system leading to or compounding disruptions in another. Strategic approaches regarding
infrastructure failures are needed to guide community mitigation and preparedness efforts. This paper defines and provides
a conceptual framework for investigating infrastructure failure interdependencies (IFIs) from the standpoint of societal impacts.
In order to identify empirical patterns, a unique database has been developed of IFIs observed in major electric power outage
events. This paper presents analysis of this data for a major Canadian disaster, the 1998 Ice Storm that affected the northeastern
region of the country. The analysis identifies IFIs due to power outage caused by the storm that are of greatest societal
concern. These represent potential foci for effective, targeted pre-disaster mitigation and preparedness efforts. The framework
and approach are broadly applicable across a range of natural and human-induced hazards. 相似文献
6.
Stanley A. Changnon 《Natural Hazards》2007,43(3):295-301
A market place designed to provide a variety of weather-sensitive institutions with products for dealing with their risks
from weather-climate hazards has been developing in recent years. Shifts in demographics, growing population, and greater
wealth across the U.S., coupled with de-regulation of utilities and expansion of global economics, have increased corporate
vulnerability to weather/climate extremes. Availability of long-term quality climate data and new technologies have allowed
development of weather-risk products. One widely used by electric-gas utilities is weather derivatives. These allow a utility
to select a financially critical seasonal weather threshold and for a price paid to a provider, to get financial payments
if this threshold is exceeded. Another new product primarily used by the insurance industry is weather risk models. These
define the potential risks of severe weather losses across a region where little historical insured loss data exists. Firms
develop weather-risk models based on historical storm information combined with a target region’s societal, economic, and
physical conditions. Examples of the derivatives and weather-risk models and their uses are presented. These various endeavors
of the new weather market exhibit the potential for dealing with shifts in weather risks due to a change in climate. 相似文献
7.
Some studies suggest that creep parameters should be determined using a greater quantity of creep test data to provide more reliable prediction regarding the deformation of soft soils. This study aims to investigate the effect of loading duration on model updating. One‐dimensional consolidation data of intact Vanttila clay under different loading durations collected from the literature is used for demonstration. The Bayesian probabilistic method is used to identify all unknown parameters based on the consolidation data during the entire consolidation process, and their uncertainty can be quantified through the obtained posterior probability density functions. Additionally, the optimal models are also determined from among 9 model candidates. The analyses indicate that the optimal models can describe the creep behavior of intact soft soils under different loading durations, and the adopted method can evaluate the effect of loading duration on uncertainty in the creep analysis. The uncertainty of a specific model and its model parameters decreases as more creep data are involved in the updating process, and the updated models that use more creep data can better capture the deformation behavior of an intact sample. The proposed method can provide quantified uncertainty in the process of model updating and assist engineers to decide whether the creep test data are sufficient for the creep analysis. 相似文献
8.
Global exponential water demand has resulted in the quantity and quality of household water declining rapidly in recent years. Across Sub-Saharan Africa, many small to medium size towns growing at more than 5% per annum provide the region’s momentum for urbanisation. Owing to the dismal performances of water utilities companies, urban populations have tended to resort to diverse and unsafe sources of household water. Illustrating with the city of Buea in the coastal south west Cameroon, this paper examines the changing trends in water sources and the potential health risks to its populations. It relied on a blend of information ranging from reviews of relevant secondary sources, empirical data to field surveys and laboratory analysis. Key findings point to a high level of water misallocation and non-revenue water by the water utility company; a growing movement of households from the certified pipe-borne water source to unimproved sources as follows: 36% to springs, 20% to wells, 25% to water vendors, 27% to rainwater, and 22% to boreholes and only 11% from open streams to piped water. This has resulted in the presence of coliform bacteria in all alternative water sources in Buea, corroborated by hospital returns on water borne intestinal bacterial infections. Given the proven efficiency of water distribution via public pumps and smaller retailers, there is the urgent need for a change of the water distribution paradigm in small and medium size cities in Sub-Saharan Africa to increase access for more people than through the more costly home connections preferred by utility companies. 相似文献
9.
New estimates of changes in the duration of the navigation period for the Northern Sea Route (NSR) are obtained based on calculations with the current generation of global climate models under moderate anthropogenic impacts in the 21st century. In order to obtain more reliable estimates, it was analyzed whether or not the present climate models can simulate both the average conditions of sea ice and their interannual variation and tendencies to change in the Arctic basin, in particular on the NSR, as compared to the satellite data for recent decades. 相似文献
10.
Consideration of within-earthquake ground-motion correlation is essential for the estimation of seismic hazards, damage, and loss for spatially distributed systems. In many seismically active regions, the strong motion data of real engineering significance are completely unavailable or very scarce. The absence of necessary data does not allow developing regional empirical correlation models, and the models obtained for other regions should be used with correspondent sensitivity analysis. The level of within-earthquake correlation may vary in broad range; therefore, development of correspondent criteria for selection from available models is important. In this paper, we analyzed the performance of a system of critical elements of electric power network (substations) depending on variations in within-earthquake correlation. The performance is described as probability of different levels of non-functionality, i.e., percentage of area suffering power outage, and probability of expected number of customers without power. We have shown that the proper choice of the within-earthquake correlation model is critical in comprehensive estimations of functionality of substations in electrical power system. Skipping the ground-motion variability and within-earthquake correlation may lead to unreliable results. Relevance of geology-based within-earthquake correlation models has been demonstrated, and a scheme, which allows reducing uncertainty in the choice of realistic correlation, has been proposed. 相似文献
11.
《Geoforum》2018
The paper explores value chain governance through a discourse approach to an event which included an exhibition and a conference. This approach appears promising for investigating industries in their formative phase and is particularly relevant for new renewable energy sectors. By studying the European offshore wind value chain, the paper investigates the coupling between wind industries and offshore industries as an encounter of various conventions. The key speakers at the conference, particularly those from the utility companies, introduced new principles for organizing the value chains they are leading, in order to reduce costs, and turn the immature sector into a mature one. Their storyline of industrialization by standardization breaks, however, with the storyline demonstrated by the firms in offshore oil and gas, and maritime industries at the exhibition. The latter offshore suppliers find evidence of quality in their business history and their trust-based relations to their clients. Theoretically the paper contributes to the global value chain governance debate by offering another perspective on power. The discourse approach helps us explain how influential actors could enforce one convention over another. The paper contributes methodically by suggesting a discourse approach to events. Events appear as a significant arena for negotiating industry formation and convenient for researcher’s data gathering for text analysis. 相似文献
12.
Mechanics-based restoration has been seen by some in the structural geology community as a panacea – a new technology that melds the retrodeformational merits of kinematic balancing with principles of continuum mechanics. The method has been touted for its ability to simulate complex 3D systems without assumptions of plane strain, allowing for heterogeneous fault slip distributions and mechanical interaction of fault segments. It has been suggested as a means to predict distributions of geologic strain and associated small-scale structures; however, we demonstrate that the kinematics of restoration models may differ significantly from forward deformation. Restoration models are governed by boundary conditions that are different from the forces driving forward geologic deformation. Models may be improved by supplementing restoration boundary conditions with loads that attempt to reverse tectonic strain, but unphysical artifacts persist. Mechanics-based restoration may be an appropriate tool for traditional applications of kinematic models including validation of structural interpretation and modeling geometric evolution; however, more subtle features, particularly strain distribution, should be treated with skepticism. Restoration models may provide insights to the initial configuration of forward mechanical models with physically appropriate boundary conditions and non-linear material behavior. Forward models provide the best means for simulating deformation and predicting subsidiary structures. 相似文献
13.
Design rainfall intensity–frequency–duration data are a basic input to many water-related development projects. To derive design rainfalls, one needs long period of recorded rainfall data. Although daily rainfall data are generally widely available, short-duration rainfall data are scarce. For many urban applications, design rainfalls for much shorter durations are needed, which cannot be obtained directly from daily read rainfall data. This paper presents a simple approach that can be adopted to derive design rainfalls of short durations using daily rainfall data and other physio-climatic characteristics using a novel ‘index frequency combined with parameter regression technique’. This uses L moments to reduce the impacts of sampling variability in the analysis. Furthermore, this adopts generalised least squares regression to account for the inter-station correlation of the rainfall data in the analysis. The proposed method is applied to a pilot data set consisting of 203 rainfall stations across Australia. An independent Monte Carlo cross-validation test shows that the proposed method is capable of generating consistent and accurate design rainfall estimates from 6-min to 12-h duration. The developed technique can be adapted to other countries where there is a scarcity of short-duration rainfall data, but daily rainfall data are abundant. 相似文献
14.
Disruption of the natural patterns of freshwater flow into estuarine ecosystems occurred in many locations around the world beginning in the twentieth century. To effectively restore these systems, establishing a pre-alteration perspective allows managers to develop science-based restoration targets for salinity and hydrology. This paper describes a process to develop targets based on natural hydrologic functions by coupling paleoecology and regression models using the subtropical Greater Everglades Ecosystem as an example. Paleoecological investigations characterize the circa 1900 CE (pre-alteration) salinity regime in Florida Bay based on molluscan remains in sediment cores. These paleosalinity estimates are converted into time series estimates of paleo-based salinity, stage, and flow using numeric and statistical models. Model outputs are weighted using the mean square error statistic and then combined. Results indicate that, in the absence of water management, salinity in Florida Bay would be about 3 to 9 salinity units lower than current conditions. To achieve this target, upstream freshwater levels must be about 0.25 m higher than indicated by recent observed data, with increased flow inputs to Florida Bay between 2.1 and 3.7 times existing flows. This flow deficit is comparable to the average volume of water currently being diverted from the Everglades ecosystem by water management. The products (paleo-based Florida Bay salinity and upstream hydrology) provide estimates of pre-alteration hydrology and salinity that represent target restoration conditions. This method can be applied to any estuarine ecosystem with available paleoecologic data and empirical and/or model-based hydrologic data. 相似文献
15.
抽取地下水引起的地表变形对地面建(构)筑物的正常使用和结构安全构成了严重威胁。深入研究抽水地表变形预测理论对于沉降灾害防治具有重要意义。由于土体模型选择和土工参数测定上的困难,基于比奥固结理论的数值求解方法在计算抽水地表变形上尚未取得理想效果。文章将随机介质理论与一维固结理论结合,建立了新的抽水地表变形时空预测模型。首先,利用一维固结微分方程,建立反映地面沉降时间效应的半经验计算模型;其次,在分析抽水地面沉降空间分布规律的基础上,利用随机介质理论研究抽水地面沉降空间分布特征;再次,综合考虑抽水地面沉降的时间效应和空间分布形态,建立抽水地面沉降的时空耦合预测模型及抽水地表倾斜、水平移动、水平变形、曲率的时空计算模型。利用这些模型计算地表变形共需5个计算参数,介绍了参数求解方法。最后,利用上述时空耦合计算模型预测某地单井抽水引起地表变形的时空规律。研究表明,所建立的抽水地表变形预测模型能准确地反映抽水地表变形的时空规律,能方便、快捷地预测地下水开采引起的地表变形。 相似文献
16.
A major assumption of the Empirical Transport Model (ETM), widely adopted by both electric utilities and regulatory agencies
for estimating the effects of entrainment mortality on fish populations in estuaries, is that the fraction of ichthyoplankton
entrained varies only in response to changes in water withdrawals, not to changes in freshwater flow. We evaluated this assumption
using a particle-tracking model to estimmate the probability of entrainment at power plants on the Hudson River during low
and high freshwater flow periods and comparing those probabilities with estimates calculated from the ETM. We found that freshwater
flow had a profound effect on the probability of entrainment. Both the number of river regions from which particles were entrained
and the probabilities of entrainment for particles in those river regions differed between low-flow and high-flow periods.
During high flow, particles spent less time in the grid box next to the intakes, reducing the probability of entrainment for
particles released in the river region of each power plant and the average probability of entrainment across all regions at
three power plants. The reduced probability of entrainment for particles released in the river regions of two power plants
was offset by higher entrainment for particles upriver of these power plants. Although the average probabilities of entrainment
across all river regions estimated with the particle-tracking model and the ETM were relatively similar for some power plants
at high flow, low flow, or both, the probabilities for each river region differed considerably between the models. The number
of river regions from which particles were entrained using the ETM was consistently undersestimated, resulting in probabilities
for regions where entrainment occurred that were biased high compared with the particle-tracking model. 相似文献
17.
Matthew J. Kohn 《Geochimica et cosmochimica acta》2008,72(15):3758-3770
Many fossils are assumed to take up trace elements by a process of combined diffusion plus adsorption (DA), yet in principle composition profiles can be explained by several different diffusion-limited processes, including diffusion plus reaction or recrystallization (DR) and double-medium diffusion (DMD). The DA and DMD models are supported by REE and U composition profiles across fossil teeth, measured by laser-ablation ICP-MS, that show error-function - like diffusion profiles into enamel from the dentine-enamel interface and concentrations in the interior of enamel that are at original biogenic levels or higher. Published composition and age profiles in some Pleistocene bones may be better explained by a DR model. All three diffusion models imply linear behavior between age and distance squared, vastly simplifying U-series dating methods for Pleistocene fossils. Modeled uptake rates for fossil teeth yield a strict minimum bound on durations of about one decade to one century. The similarity of diffusion profiles in teeth, irrespective of depositional ages ranging from ∼30 ka to >30 Ma, implies that uptake occurred quickly, with a maximum duration of a few tens of kyr for typical fossil enamel; faster uptake is implied for typical fossil bone and dentine. Disparities in these uptake estimates compared to some archeological bone may reflect sampling and preservation bias for paleontological vs. archeological materials. 相似文献
18.
通过对郯庐断裂渤南段3 个分支几何构造样式、断裂活动速率和伸展量、优势伸展方向等运动学特征,以及构造演化特征等方面的对比分析,总结了与之对应的斜向伸展-弱走滑改造、斜向伸展-强走滑叠加、持续强走滑拉分3 种构造成因类型,并阐明了不同成因演化模式对圈闭形成、储层发育和油气运移的控制作用,建立了各分支构造-成藏响应关系。结果表明,新生代以来渤海南部海域处于地幔隆升导致的南北向引张和太平洋板块斜向俯冲形成的北东向右旋剪切双重应力场中,郯庐断裂的3 个分支具有相同的构造演化阶段,但各个时期局部应力场的不同导致了它们构造特征的差异,进而影响和控制了各分支在油气聚集时期、层位、规模等方面的成藏差异性。 相似文献
19.
20.
Adrian Cashman 《Geoforum》2006,37(4):488-504
In 1997 there was a change in government in the UK with the Labour Party coming into power for the first time since 1979. Among the commitments made was the intention to put sustainability at the heart of government and decision-making. There was also a commitment to introduce reforms of the utility sector. In part this was a response to public concern over the conduct and behaviour of the privatised utilities, made more pertinent in the case of the water sector by the impact of several seasons of below average rainfall and high levels of leakage. In light of this the need for change took on a particular urgency. This paper examines some of the developments in water regulation under the 1997-2001 Labour administration. Through two sets of events; the 1997 Water Summit and the 1997-1999 Price Review the paper examines the discursive processes through which sustainability has been incorporated into water regulation. It discusses the changes in the practices of regulation and whether these could be characterised as the adoption of sustainability by the water sector or a strategy of adaptation to accommodate sustainability within an existing economic paradigm. 相似文献