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1.
Bimal Kanti Paul 《The Professional geographer》2013,65(3):401-414
Cyclone Sidr, a Category 4 storm, struck the southwestern coast of Bangladesh on 15 November 2007. Despite early cyclone warnings and emergency evacuation orders for coastal residents, thousands of individuals stayed in their homes. This study examines Sidr victims’ responses to cyclone warnings and evacuation orders, and explores the factors that would explain why the victims did or did not comply with the orders. Based on survey data collected from 277 Sidr survivors living in the four most severely impacted coastal districts, this study found that more than 75 percent of all respondents were aware of the cyclone warnings and evacuation orders before Sidr's landfall. Despite the efforts of the Bangladesh government, there were lapses in cyclone warnings and evacuation procedures. Field data also reveal several reasons cited by respondents for not complying with evacuation orders. Multivariate analyses of survey data show that trust in warning messages was the most important determinant in the decision to seek refuge in safer shelters, followed by distance to nearest shelter and annual level of education. Several recommendations have been made to improve cyclone warnings and the use of public shelters for similar future events. 相似文献
2.
Hazard warnings and responses to evacuation orders: the case of Bangladesh's cyclone Sidr 总被引：2，自引：0，他引：2
On 15 November 2007 Cyclone Sidr, a category 4 storm, struck the southwestern coast of Bangladesh. Despite early cyclone warnings and evacuation orders for coastal residents, thousands of individuals stayed in their homes. This study examines dissemination of the warning, assesses the warning responses, and explores the reasons why many residents did not evacuate. Field data collected from 257 Sidr survivors in four severely affected coastal districts revealed that more than three-fourths of all respondents were aware of the cyclone warnings and evacuation orders. Despite the sincere efforts of the Bangladesh government, however, lapses in cyclone warnings and evacuation procedures occurred. Field data also revealed several reasons why evacuation orders were not followed. The reasons fell into three broad groups: those involving shelter characteristics; the attributes of the warning message itself; and the respondents' characteristics. Based on our findings, we recommend improved cyclone warnings and utilization of public shelters for similar events in the future. 相似文献
3.
Zlatina Anguelova Douglas A. Stow John Kaiser Philip E. Dennison Tom Cova 《The Professional geographer》2013,65(2):230-247
Wildfires create a risk to pedestrians traveling through rural areas, because they might not be aware of the presence of a wildfire or its direction and rate of spread until is too late to successfully evacuate. In wildland areas of southern San Diego County, immigrants crossing the U.S.–Mexico border and border security agents are particularly at risk to wildfires. The objective of this study is to develop a framework of analysis and associated tools for examining the combined behavior of wildfires and pedestrian mobility to assess the potential threat of fire to pedestrians in wildland areas. Outputs from a geographic information system (GIS) overlay model for determining potentially dangerous fire zones, the Wildland–Urban Interface Evacuation (WUIVAC) model, and a model of pedestrian mobility in wildland areas were combined to generate wildfire risk to pedestrian maps. The key technical contributions of the study are the development and testing of the pedestrian mobility model and the framework and logic for integrating the results of three GIS-based models. The applied geography contribution is the testing of two scenarios of high risk from wildfires to pedestrians within the U.S.–Mexico border zone of San Diego County, California. The study results show that the travel times calculated by the pedestrian mobility model appear to be realistic and are affected by the terrain and vegetation characteristics of a study site, whereas the evacuation trigger buffers (ETBs) from WUIVAC are mostly influenced by the wind speed and direction parameters of the FlamMap fire spread model. A moderate fire danger to pedestrians in the most remote wildland locations of the study area is determined. The scenario test results suggest that if a wildfire occurs within 2 km (extreme southwesterly winds) or 6 km (extreme northeasterly wind) of pedestrians in the worst case location within the San Diego border region they would likely not have a sufficient amount of time to reach a nearby safety zone. 相似文献
4.
Zhifen Chen Xiang Chen Jin Chen 《International journal of geographical information science》2013,27(8):1612-1630
The problem of emergency facility location is a critical component in evacuation planning. The emergence of geographic information systems (GIS) has provided a useful operational platform to assist this issue. A previously overlooked facet is the consideration of a hierarchical structure in the placement of emergency shelters. Due to the fact that survivors' needs change over time during post-disaster evacuations, shelters have now been categorized on a temporal scale based on their functions at different evacuation phases. This article proposes a three-level hierarchical location model for optimizing the placement of earthquake shelters by taking into account this temporal variance. The article not only scrutinizes the modeling procedure but also implements the model in a planning area with many real-world details. Based on the optimization results derived from a GIS context, we have found that the quality of the earthquake response procedure is not only dependent on the placement strategy of shelters, but more importantly on the financial constraints imposed on the planning and construction of these shelters. A discussion has been proposed to balance the trade-off between budget planning and evacuation efficiency. As the first attempt to model the hierarchical configuration of emergency shelters with specific focus on evacuees' escalating sheltering demands, this article will be of great significance in helping policy makers consider both the spatial and financial aspects of the strategic placement of emergency shelters. 相似文献
5.
Although anisotropic least-cost-distance (LCD) modeling is becoming a common tool for estimating pedestrian-evacuation travel times out of tsunami hazard zones, there has been insufficient attention paid to understanding model sensitivity behind the estimates. To support tsunami risk-reduction planning, we explore two aspects of LCD modeling as it applies to pedestrian evacuations and use the coastal community of Seward, Alaska, as our case study. First, we explore the sensitivity of modeling to the direction of movement by comparing standard safety-to-hazard evacuation times to hazard-to-safety evacuation times for a sample of 3985 points in Seward's tsunami-hazard zone. Safety-to-hazard evacuation times slightly overestimated hazard-to-safety evacuation times but the strong relationship to the hazard-to-safety evacuation times, slightly conservative bias, and shorter processing times of the safety-to-hazard approach make it the preferred approach. Second, we explore how variations in land cover speed conservation values (SCVs) influence model performance using a Monte Carlo approach with one thousand sets of land cover SCVs. The LCD model was relatively robust to changes in land cover SCVs with the magnitude of local model sensitivity greatest in areas with higher evacuation times or with wetland or shore land cover types, where model results may slightly underestimate travel times. This study demonstrates that emergency managers should be concerned not only with populations in locations with evacuation times greater than wave arrival times, but also with populations with evacuation times lower than but close to expected wave arrival times, particularly if they are required to cross wetlands or beaches. 相似文献
6.
In this paper, a spatiotemporal framework is developed for identifying building vulnerabilities and content evacuations during riverine flooding events. This work investigates the spatiotemporal properties required to trigger building contents evacuations in the floodplain during a flood event. The spatial properties for building risks are based on topography, flood inundation, building location, building elevation, and road access to determine five categories of vulnerability, vulnerable basement, flooded basement, vulnerable first-floor, flooded first-floor, and road access. Using this framework, a model designed to track the spatiotemporal patterns of building evacuations is presented. The model is based upon real-time flood forecast predictions that are linked with building properties to create a model that captures the spatiotemporal ordering of building vulnerabilities and building content evacuations. Applicable to different communities at risk from flooding, the evacuation model is applied to a historical flood for a university campus, demonstrating how the defined elements are used to derive a pattern of vulnerability and evacuation for a campus threatened by severe flooding. 相似文献
7.
Research on disaster response frequently uses volunteered geographic information (VGI), due to its capability to provide near real-time information during and after a disaster. It is much less commonly used in spatial planning related to disaster management. However, VGI appears to have considerable potential for use in spatial planning and offers some advantages over traditional methods. For example, VGI can capture residents' preferences in a much faster, more timely, and more comprehensive fashion than is possible with, for example, questionnaires and surveys. This research investigates the usefulness of VGI for planning flood evacuation shelters. Using Jakarta, Indonesia, as a case study, we use VGI to capture the locations of flood evacuation shelters based on residents' preferences during flood periods in 2013–2014 and 2014–2015 and compare these with the locations of official shelters. Floods frequently affect Jakarta and the city administration uses VGI in flood emergency responses. Moreover, Jakarta has been identified as having the largest number of active Twitter users among cities worldwide. Thus, Jakarta is an appropriate place to study the use of VGI for planning evacuation shelters. VGI generated by Twitter users was used to identify the shelter locations preferred by Jakarta residents, and more precisely the flood evacuees. Of 171,046 tweets using keywords relating to flood evacuation, the content of 306 tweets indicated that they had been sent from inside or near evacuation shelters. The spatial pattern showed that those tweets were sent from 215 locations, mostly located near flooded areas. The analysis further showed that 35.6% of these shelter locations preferred by residents intersected with the locations of official evacuation shelters. As a general conclusion, our study demonstrates the advantages of using VGI for spatial planning, which mainly relates to the ease of capturing community preferences over a large area. 相似文献
8.
Antonio T. Mozas-Calvache Manuel Antonio Ureña-Cámara José Luis Pérez-García 《International journal of geographical information science》2013,27(12):2362-2374
This article describes a new methodology for the planimetric control of contour lines. The method is based on the generation of buffers around the contour lines which define a 3D buffer around the maximum slope line. After that we analyze the quantity of points from a more accurate source which is inside this buffer. As a result, we obtain a distribution function of the control points included when we apply several widths to the buffers. We have also determined the angularity and height differences of these points. The method has been applied to several sets of contour line intervals derived from a digital elevation model (DEM) and to the contour lines of one published topographic map using the DEM as the control source. We have also analyzed the representative behaviour of the contour lines, taking into account the contour line interval and the detection of an uncertainty model based on the slope variation. This study demonstrates the viability of the proposed method for obtaining the uncertainty of the contour lines depending on a given level of confidence and the variability of this uncertainty in the map. Finally, we propose a range of contour line intervals based on the scale and slopes. 相似文献
9.
Quanhua Dong 《International journal of geographical information science》2018,32(2):302-323
Geometric buffers are important for spatial analysis in many applications of geographic information systems (GISs), such as environmental measurement and management, human health, urban planning, etc. Geometric buffer generation algorithms are well studied in the Euclidean space where the buffer distance is measured by Euclidean metrics; however, very few algorithms are available for generating geometric buffers on the terrain surface in a virtual globe where the buffer distance is measured by geodesic metrics. This paper proposes a tile-based method for geodesic buffer generation according to the characteristics of a virtual globe. It extends the vector tile model (VTM) to organize terrain and vector data, and the XYH algorithm is improved to build geodesic distance fields for terrain meshes. Based on the data organization and the improved XYH algorithm, a geodesic buffer is generated via three main steps: selecting and assembling tiles, updating geodesic distance fields and tracing the boundaries of buffer zones. This method is implemented with multi-scale terrain and vector data, and the experimental results show that it is valid and exact and can be applied in practical applications. 相似文献
10.
Yih-Min Wu Hiroo Kanamori Richard M. Allen Egill Hauksson 《Geophysical Journal International》2007,170(2):711-717
We explore a practical approach to earthquake early warning in southern California by determining a ground-motion period parameter τ c and a high-pass filtered displacement amplitude parameter Pd from the initial 3 s of the P waveforms recorded at the Southern California Seismic Network stations for earthquakes with M > 4.0. At a given site, we estimate the magnitude of an event from τ c and the peak ground-motion velocity ( PGV ) from Pd . The incoming three-component signals are recursively converted to ground acceleration, velocity and displacement. The displacements are recursively filtered with a one-way Butterworth high-pass filter with a cut-off frequency of 0.075 Hz, and a P -wave trigger is constantly monitored. When a trigger occurs, τ c and Pd are computed. We found the relationship between τ c and magnitude ( M ) for southern California, and between Pd and PGV for both southern California and Taiwan. These two relationships can be used to detect the occurrence of a major earthquake and provide onsite warning in the area around the station where onset of strong ground motion is expected within seconds after the arrival of the P wave. When the station density is high, the methods can be applied to multistation data to increase the robustness of onsite early warning and to add the regional warning approach. In an ideal situation, such warnings would be available within 10 s of the origin time of a large earthquake whose subsequent ground motion may last for tens of seconds. 相似文献
11.
There is an increasing need for a quick, simple method to represent diurnal population change in metropolitan areas for effective emergency management and risk analysis. Many geographic studies rely on decennial U.S. Census data that assume that urban populations are static in space and time. This has obvious limitations in the context of dynamic geographic problems. The U.S. Department of Transportation publishes population data at the transportation analysis zone level in fifteen-minute increments. This level of spatial and temporal detail allows for improved dynamic population modeling. This article presents a methodology for visualizing and analyzing diurnal population change for metropolitan areas based on this readily available data. Areal interpolation within a geographic information system is used to create twenty-four (one per hour) population surfaces for the larger metropolitan area of Salt Lake County, Utah. The resulting surfaces represent diurnal population change for an average workday and are easily combined to produce an animation that illustrates population dynamics throughout the day. A case study of using the method to visualize population distributions in an emergency management context is provided using two scenarios: a chemical release and a dirty bomb in Salt Lake County. This methodology can be used to address a wide variety of problems in emergency management. 相似文献
12.
Buffelgrass invasions have been documented in Australia to North America, pointing to an end result of large-scale wildfires. In heavily populated areas such as Nogales, Sonora and Tucson and Phoenix, Arizona buffelgrass populations are growing exponentially. Although much research has been conducted on buffelgrass, relatively little is known about fire behaviors produced by a buffelgrass-fueled fire. To determine which abiotic and biotic characteristics best predict fire behavior, fire-behavior characteristics were measured in four prescribed fires in southern Arizona. Given that buffelgrass is known to decrease native plant richness in other ecosystems, the relationship between buffelgrass abundance and native plant cover was evaluated. Buffelgrass fires are more intense than fires in surrounding ecosystems, even in communities with comparable fuels. There is a strong negative relationship between buffelgrass cover and native plant cover. In addition, buffelgrass appears to be invading favorable microsites rather than species-poor communities and is radiating from the former sites. Historically, fire was rare in arid regions, but with the increase in fuels and because arid regions have weather that promotes intense fire behavior, as observed in this study, managers will increasingly observe and need to mitigate hazardous fires. 相似文献
13.
Xuwei Chen 《The Professional geographer》2013,65(2):160-173
This article investigates the effectiveness of simultaneous and staged evacuation strategies for hurricane evacuations of Galveston Island using agent-based microsimulation techniques. In the simultaneous strategy the entire population is informed to evacuate simultaneously, whereas in a staged evacuation strategy, people are informed to evacuate in a sequence. The results suggest that (1) the most efficient staged evacuation strategy can help reduce the evacuation time for Galveston Island by approximately one hour, (2) previous studies might have underestimated the evacuation time of Galveston, and (3) an evacuation under the rapid response assumption does not necessarily lead to an effective evacuation. 相似文献
14.
Sarah F. Trainor Monika Calef David Natcher F. Stuart Chapin III A. David McGuire Orville Huntington Paul Duffy T. Scott Rupp La'Ona DeWilde Mary Kwart Nancy Fresco & Amy Lauren Lovecraft 《Polar research》2009,28(1):100-118
This paper explores whether fundamental differences exist between urban and rural vulnerability to climate-induced changes in the fire regime of interior Alaska. We further examine how communities and fire managers have responded to these changes and what additional adaptations could be put in place. We engage a variety of social science methods, including demographic analysis, semi-structured interviews, surveys, workshops and observations of public meetings. This work is part of an interdisciplinary study of feedback and interactions between climate, vegetation, fire and human components of the Boreal forest social–ecological system of interior Alaska. We have learned that although urban and rural communities in interior Alaska face similar increased exposure to wildfire as a result of climate change, important differences exist in their sensitivity to these biophysical, climate-induced changes. In particular, reliance on wild foods, delayed suppression response, financial resources and institutional connections vary between urban and rural communities. These differences depend largely on social, economic and institutional factors, and are not necessarily related to biophysical climate impacts per se. Fire management and suppression action motivated by political, economic or other pressures can serve as unintentional or indirect adaptation to climate change. However, this indirect response alone may not sufficiently reduce vulnerability to a changing fire regime. More deliberate and strategic responses may be required, given the magnitude of the expected climate change and the likelihood of an intensification of the fire regime in interior Alaska. 相似文献
15.
科学评估避难场所的服务效率是提高城市应急水平的前提。传统对避难场所服务效率的评估多偏重于避难场所空间布局的合理性,缺少对避难者的空间布局和避难行为等避难需求的考虑,这会使评估结果造成偏差,从而容易引起资源配置的低效率。本文构建了多主体模拟模型,模拟避难者灾后对避难场所的选择、奔跑、安置等关键疏散行为过程,量化评估该地区避难场所服务效率。本文对比了两种量化评估指标在同一案例评估的差异性,一种是传统方法中空间可达性(服务半径覆盖率),一种是利用疏散行为模拟计算出的避难成功率;北京市海淀区的实证研究显示两项指标在同一案例区有巨大差异。这一分析结果显示,传统评估仅利用服务半径覆盖率这一指标来分析避难场所布局现状及规划的合理性存在不足。通过避难疏散行为的模拟发现,以下指标的使用有望辅助提高评估的真实性：①避难场所的利用效率。由于设施的利用效率不均衡,会导致避难场所超容或闲置的情况。在充分考虑避难场所的有效服务面积和服务人口的基础上,设计“人均避难面积”等反应利用效率的指标就显得十分必要。②避难标识系统的连通性。避难模拟的实验显示避难标识系统可能对避难者逃生疏散具有分流和引导作用,据此,避难场所与周边居民区的标识系统的连通性也是评价其服务效率的关键指标。 相似文献
16.
Oil Spills and Community Resilience: Uneven Impacts and Protection in Historical Perspective 
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下载免费PDF全文 Louisiana's coastal residents have endured centuries of hurricanes and decades of oil spills. Locally based, inherent resilient practices have enabled them to persist in place. This paper documents the evolution of actions taken by Louisiana's coastal residents that constitute effective resilient activities in the aftermath of disruptive events. It compares the efforts that arose from coastal communities that were rooted in local environmental knowledge with generic external programs designed to enable hazard mitigation, emergency response, and recovery form damaging hurricanes and oil spills. Additionally, it will identify points of opportunity to fortify resilience by integrating inherent and formal resilience. 相似文献
17.
Ran Wei Alan T. Murray 《International journal of geographical information science》2016,30(3):432-450
Location siting is an important part of service provision, with much potential to impact operational efficiency, safety, security, system reliability, etc. A class of location models seeks to optimize coverage of demand for service that is continuously distributed across space. Decision-making and planning contexts include police/fire resource allocation for a community, siting cellular towers to support cell phone signal transmission, locating emergency warning sirens to alert the public of severe weather and other related dangers, and many others as well. When facilities can be sited anywhere in continuous space to provide coverage to an entire region, this is a very computationally challenging problem to solve because potential demand for service is everywhere and there are an infinite number of potential facility sites to consider. This article develops a new parallel solution approach for this location coverage optimization problem through an iterative bounding scheme on multi-core architectures. The developed approach is applied to site emergency warning sirens in Dublin, Ohio, and fire stations in Elk Grove, California. Results demonstrate the effectiveness and efficiency of the proposed approach, enabling real-time analysis and planning. This work illustrates that the integration of cyberinfrastructure can significantly improve computational efficiency in solving challenging spatial optimization problems, fitting the themes of this special issue: cyberinfrastructure, GIS, and spatial optimization. 相似文献
18.
Wei-Ning Xiang Wendy Lee Stratton 《International journal of geographical information science》2013,27(4):499-510
Abstract Mapping variable stream buffers in a vector environment in which buffer width values are delineated often yields inaccurate results. Possible vector solutions are either ineffective or inefficient, An alternate raster approach is presented here in which a buffer effectiveness-achievement function (b-function) is introduced to map desirable buffer zones at an individual cell level based upon areal differentiations in physical and ecological conditions. The implementation of b-function is made feasible by a GIS procedure devised in this article. This tested method can be extended to a variety of variable buffer studies, such as visual buffers, noise buffers, greenways, and urban natural buffers. ‘A robe can never be made of the fur from one fox's axillae’ (A Chinese idiom). 相似文献
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20.
Majid Esmaelian Francisco J. Santos Arteaga Sommayeh Mohammadi 《International journal of geographical information science》2013,27(7):1187-1213
Earthquakes occurring in urban areas constitute an important concern for emergency management and rescue services. Emergency service location problems may be formulated in discrete space or by restricting the potential location(s) to a specified finite set of points in continuous space. We propose a Multicriteria Spatial Decision Support System to identify shelters and emergency service locations in urban evacuation planning. The proposed system has emerged as an integration of the geographical information systems (GIS) and the multicriteria Decision-Making method of Preference Ranking Organization Method for Enrichment Evaluation IV (PROMETHEE IV). This system incorporates multiple and often conflicting criteria and decision-makers’ preferences into a spatial decision model. We consider three standard structural attributes (i.e., durability density, population density, and oldness density) in the form of spatial maps to determine the zones most vulnerable to an earthquake. The information on these spatial maps is then entered into the ArcGIS software to define the relevant scores for each point with regards to the aforementioned attributes. These scores will be used to compute the preference functions in PROMETHEE IV, whose net flow outranking for each alternative will be inputted in ArcGIS to determine the zones that are most vulnerable to an earthquake. The final scores obtained are integrated into a mathematical programming model designed to find the most suitable locations for the construction of emergency service stations. We demonstrate the applicability of the proposed method and the efficacy of the procedures and algorithms in an earthquake emergency service station planning case study in the city of Tehran. 相似文献