Coupling Natural Hazard Estimates with Road Network Analysis to Assess Vulnerability and Risk: Case Study of Freetown (Sierra Leone)

2019 ◽  
Vol 2673 (8) ◽  
pp. 11-24
Author(s):  
Andrew Nelson ◽  
Sarah Lindbergh ◽  
Lucy Stephenson ◽  
Jeremy Halpern ◽  
Fatima Arroyo Arroyo ◽  
...  
Keyword(s):  
Climate Change ◽  
Decision Making ◽  
Sierra Leone ◽  
Road Network ◽  
Natural Hazard ◽  
Transportation Infrastructure ◽  
The Road ◽  
Public Data ◽  
Road Intersections ◽  
Flooding Events

Many of the world’s most disaster-prone cities are also the most difficult to model and plan. Their high vulnerability to natural hazards is often defined by low levels of economic resources, data scarcity, and limited professional expertise. As the frequency and severity of natural disasters threaten to increase with climate change, and as cities sprawl and densify in hazardous areas, better decision-making tools are needed to mitigate the effects of near- and long-term extreme events. We use mostly public data from landslide and flooding events in 2017 in Freetown, Sierra Leone to simulate the events’ impact on transportation infrastructure and continue to simulate alternative high-risk disasters. From this, we propose a replicable framework that combines natural hazard estimates with road network vulnerability analysis for data-scarce environments. Freetown’s most central road intersections and transects are identified, particularly those that are both prone to serviceability loss due to natural hazard and whose disruption would cause the most severe immediate consequences on the entire road supply in terms of connectivity. Variations in possible road use are also tested in areas with potential road improvements, pointing to opportunities to harden infrastructure or reinforce redundancy in strategic transects of the road network. This method furthers network science’s contributions to transportation resilience under hydrometeorological hazard and climate change threats with the goal of informing investments and improving decision-making on transportation infrastructure in data-scarce environments.

Study on Optimization Model of Multiple Depot Vehicle Scheduling in Logistics Distribution of Expressway Service Area

2012 ◽  
Vol 253-255 ◽  
pp. 1486-1491
Author(s):  
Qian Zhou ◽  
Chun Long Xu ◽  
Jun Liu
Keyword(s):  
Decision Making ◽  
Optimization Model ◽  
Road Network ◽  
Ant Colony Algorithm ◽  
Reliability Theory ◽  
Vehicle Scheduling ◽  
Logistics Distribution ◽  
The Road ◽  
Service Areas ◽  
Multiple Depot

Based on the unblocked reliability theory of the road network, combined with the characteristics of the logistics distribution of expressway service areas, the concept of network unblocked reliability on logistics distribution was put forward. Under the reliability analysis, the optimization model of multi objective, multi depot and open vehicle scheduling on logistics distribution of highway service areas was established, and the ant colony algorithm was designed. In the end an example was analyzed to validate the usability of the optimization model by comparing with saving mileage, which demonstrates the established optimization model of multiple depot vehicle scheduling is of a better practical value to guide the optimization decision making of logistics distribution network and to improve the reliability of logistics distribution of expressway service areas.

scholarly journals Application of AHP to Road Selection

2020 ◽  
Vol 9 (2) ◽  
pp. 86 ◽  
Author(s):  
Yuan Han ◽  
Zhonghui Wang ◽  
Xiaomin Lu ◽  
Bowei Hu
Keyword(s):  
Decision Making ◽  
Road Network ◽  
Analytic Hierarchy ◽  
Ahp Model ◽  
The Road ◽  
Points Of Interest ◽  
Adaptive Thresholds ◽  
Contextual Characteristics ◽  
Hierarchy Process ◽  
Contextual Characteristic

The analytic hierarchy process (AHP), a decision-making method, allows the relative prioritization and assessment of alternatives under multiple criteria contexts. This method is also well suited for road selection. The method for road selection based on AHP involves four steps: (i) Points of Interest (POIs), the point-like representations of the facilities and habitations in maps, are used to describe and build the contextual characteristic indicator of roads; (ii) form an AHP model of roads with topological, geometrical, and contextual characteristic indicators to calculate their importance; (iii) select roads based on their importance and the adaptive thresholds of their constituent density partitions; and (iv) maintain the global connectivity of the selected network. The generalized result at a scale of 1:200,000 by AHP-based methods better preserved the structure of the original road network compared with other methods. Our method also gives preference to roads with relatively significant contextual characteristics without interfering with the structure of the road network. Furthermore, the result of our method largely agrees with that of the manual method.

Integrated Framework for Risk and Resilience Assessment of the Road Network under Inland Flooding

2019 ◽  
Vol 2673 (12) ◽  
pp. 182-190 ◽  
Author(s):  
Ning Zhang ◽  
Alice Alipour
Keyword(s):  
Risk Assessment ◽  
Risk Analysis ◽  
Road Network ◽  
Transportation Network ◽  
User Equilibrium ◽  
Vulnerability Analysis ◽  
Integrated Framework ◽  
The Road ◽  
Flooding Events ◽  
Resilience Assessment

A transportation network facilitates the connectivity of local residential areas, improves capability for movement of goods, and contributes to economic development. Recent flooding events in the U.S. have highlighted the vulnerability of our transportation network to such events. Flooding, a predominant destructive hazard, leads to significant direct damages to physical road infrastructures and also results in significant indirect losses to communities that rely on the road network. Decision-makers, designers and planners all must understand the risks associated with such events and make adequate preparations for them. This paper proposes a holistic framework for integrating flooding hazards with vulnerability analysis of transportation road infrastructures, topologic risk analysis, and flow-based risk assessment. Vulnerability analysis of infrastructures reveals the extent of closure on roads and bridges. Topologic risk analysis, based on graph theory, provides immediate information on network characteristics that could be linked to instantaneous connectivity measures. Flow-based risk assessment uses a user equilibrium model to compute traffic time for the entire network for assessment of user losses from increased traffic time. Finally, the developed framework can be used to assess risks for a segment of the primary road system in the state of Iowa when facing flooding events with return periods of 2, 50, 200 and 500 years. It is expected that this integrated framework and the network performance measures could inform future resilience assessment and enhancement strategies in the studied region and provide a framework for other states that might wish to adopt this approach.

scholarly journals Modeling of Influence of Climate Change Character on the Territory of the Cryolithozone on the Value of Risks for the Road Network

2020 ◽  
Vol 16 (07) ◽  
pp. 65
Author(s):  
Yury Vasilievich Trofimenko ◽  
Anatoly Nikolaevich Yakubovich ◽  
Irina Anatolievna Yakubovich ◽  
Elena Vldimirovna Shashina
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Road Network ◽  
Climatic Conditions ◽  
Average Risk ◽  
The Road ◽  
Climate Risks ◽  
Warming Pattern ◽  
Soil Settlement ◽  
Predicted Risk

The level of climate risks is proposed to be estimated by the amount of thawing soil settlement in the formation of automobile roads, corresponding to the accepted scenario of the climate change. An updated algorithm is presented, according to which the average risk assessment for a 4-year period is divided into a risk assessment for individual years. Calculations performed for the climatic conditions of Yakutsk and Urengoy establish a significant dependence of the predicted risk on the warming pattern. The level of risk predicted when the average annual air temperature increases by 2 degrees is estimated as average (up to 526 points on a 1000-point scale). The most appropriate method of reducing this risk is to perform timely repairs to bring the road to the standard technical and operational condition without the use of special technologies for regulating the temperature regime of soil.

The conditions of practical action: Neoliberalism and sustainability in the Australian road construction industry

2016 ◽  
Vol 34 (8) ◽  
pp. 1501-1515 ◽  
Author(s):  
Cameron White
Keyword(s):  
Climate Change ◽  
Environmental Impact ◽  
Construction Industry ◽  
Road Network ◽  
Tobacco Industry ◽  
Interdisciplinary Approach ◽  
Road Construction ◽  
Infrastructure Development ◽  
Practical Action ◽  
The Road

In the last decade, in the context of debates about climate change, the Australian road construction industry has focused on increasing efficiencies within road construction processes. This approach to environmental impact management is congruent with existing (road-centric) trajectories of infrastructure development. At the same time, however, it also institutionalises the systemic environmental impacts of the road network. This article examines the historical conditions within which this focus on construction efficiencies emerged as the basis of practical action. Firstly, it examines the neoliberal strategies that led to the privatisation of the Australian road construction industry in the 1990s. Secondly, these Australian road industry strategies are compared with other industry-centred harm-management initiatives and traced back to the tobacco industry tactics of the 1950s and 1960s. Finally, this article argues for a broader, interdisciplinary approach to the analysis and management of environmental impact.

scholarly journals Sustainable Decision-Making in Road Development: Analysis of Road Preservation Policies

2020 ◽  
Vol 12 (3) ◽  
pp. 872 ◽  
Author(s):  
Angie Ruiz ◽  
Jose Guevara
Keyword(s):  
Decision Making ◽  
Road Network ◽  
Predictive Maintenance ◽  
Road Maintenance ◽  
Maintenance Policy ◽  
Long Term Effects ◽  
Support Tool ◽  
The Road ◽  
Analytic Hierarchical Process ◽  
Maintenance Policies

Road infrastructure in appropriate conditions is a requirement for the development of any country. The formulation of policies oriented to preserve road networks responds to political, socio-economic, and environmental interests. Through a hybrid methodology that integrates system dynamics (SD) and analytic hierarchical process (AHP) approaches, this paper compares some strategies employed in the development of sustainable road maintenance policies in Colombia. Using a hypothetical case study of a national road network, a set of maintenance policy alternatives are evaluated through the SD model in order to analyze the evolution of road conditions, and quantify costs and emissions. Then, a multi-criteria evaluation is performed applying the AHP methodology. Results show that in the Colombian context, decision-making processes regarding maintenance policies are highly influenced by economic factors, which lead to short-term strategies such as performing corrective maintenance over predictive maintenance. However, further analysis demonstrates that predictive maintenance allows the road network to remain in good conditions. Simultaneously, roadways in adequate conditions contribute to mitigate the environmental impact, because CO2 emissions are directly related to the interventions performed to preserve these roads. The proposed methodology can be used as a support tool to formulate maintenance policies that consider the long-term effects at the technical, environmental, and economic levels.

scholarly journals The Variable Scale Evacuation Model (VSEM): a new tool for simulating massive evacuation processes during volcanic crises

2010 ◽  
Vol 10 (4) ◽  
pp. 747-760 ◽  
Author(s):  
J. M. Marrero ◽  
A. García ◽  
A. Llinares ◽  
J. A. Rodríguez-Losada ◽  
R. Ortiz
Keyword(s):  
Road Network ◽  
Natural Hazard ◽  
Volcanic Eruptions ◽  
Civil Defense ◽  
Volcanic Risk ◽  
Emergency Plans ◽  
The Road ◽  
Hazard And Risk ◽  
Event Trees ◽  
Evacuation Model

Abstract. Volcanic eruptions are among the most awesome and powerful displays of nature's force, constituting a major natural hazard for society (a single eruption can claim thousands of lives in an instant). Consequently, assessment and management of volcanic risk have become critically important goals of modern volcanology. Over recent years, numerous tools have been developed to evaluate volcanic risk and support volcanic crisis management: probabilistic analysis of future eruptions, hazard and risk maps, event trees, etc. However, there has been little improvement in the tools that may help Civil Defense officials to prepare Emergency Plans. Here we present a new tool for simulating massive evacuation processes during volcanic crisis: the Variable Scale Evacuation Model (VSEM). The main objective of the VSEM software is to optimize the evacuation process of Emergency Plans during volcanic crisis. For this, the VSEM allows the simulation of an evacuation considering different strategies depending on diverse impact scenarios. VSEM is able to calculate the required time for the complete evacuation taking into account diverse evacuation scenarios (number and type of population, infrastructure, road network, etc.) and to detect high-risk or "blackspots" of the road network. The program is versatile and can work at different scales, thus being capable of simulating the evacuation of small villages as well as huge cities.

Sectional mapping of local roads in Spain

2008 ◽  
Vol 35 (11) ◽  
pp. 1200-1209
Author(s):  
Angel Ibeas ◽  
Hernan Gonzalo_Orden ◽  
Luigi Dell’Olio ◽  
Jose Luis Moura
Keyword(s):  
Decision Making ◽  
Road Network ◽  
Geographic Information ◽  
Decision Making Process ◽  
Northern Spain ◽  
The Road ◽  
Local Roads ◽  
Decision Making Processes ◽  
Low Volume ◽  
Road Segments

The management of any road network can be improved by gathering information about the different road segments that form it. Geographic information systems (GISs) can be used to map and manipulate the large amount of information collected. This helps managers in their analysis of the network and in the decision-making processes. This article explains the development and practical use of the latest mapping carried out on the local roads in the region of Cantabria in northern Spain. The aim of the current study was to perform a thorough analysis of the characteristics of each segment of the road network to update and restructure the existing mapping. A geographic information system (GIS) was used for consulting and analyzing the data obtained now and over previous years. Moreover, the ways this information could be used in the decision-making process were improved for a regional road network which has, in general, a low volume of traffic.

Topology Analysis for the Damaged Road Network Based MapX

2014 ◽  
Vol 1022 ◽  
pp. 321-324 ◽  
Author(s):  
Xu Ri Yin
Keyword(s):  
Decision Making ◽  
Natural Disasters ◽  
Shortest Path ◽  
Road Network ◽  
Practical Application ◽  
Topology Analysis ◽  
The Road ◽  
Highway Transportation ◽  
Key Technologies ◽  
Analysis System

Natural disasters often cause damages in different degrees to the road network, the topology analysis for the damaged road network has become more valuable and meaningful. In this paper, several key technologies to establish topological structures of the damaged road network based on MapX are discussed. On the base, an algorithm for finding the shortest path in the damaged road network is presented. At last, a brief conclusion as well as the expectation for the further study is made. This algorithm has been well applied in the Decision-making Analysis System for Highway Transportation, and the probation shows that it is faster and more flexible in the practical application.

scholarly journals AUTOMATIC EXTRACTION OF ROAD CENTERLINES AND EDGE LINES FROM AERIAL IMAGES VIA CNN-BASED REGRESSION

2020 ◽  
Vol V-2-2020 ◽  
pp. 925-932
Author(s):  
Y. Wei ◽  
X. Hu ◽  
M. Zhang ◽  
Y. Xu
Keyword(s):  
Road Network ◽  
Aerial Images ◽  
Automatic Extraction ◽  
Tensor Voting ◽  
Road Extraction ◽  
The Road ◽  
Road Width ◽  
Road Intersections ◽  
On The Road ◽  
Segmentation Problem

Abstract. Extracting roads from aerial images is a challenging task in the field of remote sensing. Most approaches formulate road extraction as a segmentation problem and use thinning and edge detection to obtain road centerlines and edge lines, which could produce spurs around the extracted centerlines/edge lines. In this study, a novel regression-based method is proposed to extract road centerlines and edge lines directly from aerial images. The method consists of three major steps. First, an end-to-end regression network based on CNN is trained to predict confidence maps for road centerlines and estimate road width. Then, after the CNN predicts the confidence map, non-maximum suppression and road tracking are applied to extract accurate road centerlines and construct road topology. Meanwhile, Road edge lines are generated based on the road width estimated by the CNN. Finally, in order to improve the connectivity of extracted road network, tensor voting is applied to detect road intersections and the detected intersections are used as guidance for the overcome of discontinuities. The experiments conducted on the SpaceNet and DeepGlobe datasets show that our approach achieves better performance than other methods.

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