Integration of stress testing with graph theory to assess the resilience of urban road networks under seismic hazards

Transportation networks daily provide accessibility and crucial services to societies. However, they must also maintain an acceptable level of service to critical infrastructures in the case of disruptions, especially during natural disasters. We have developed a method for assessing the resilience of transportation network topology when exposed to environmental hazards. This approach integrates graph theory with stress testing methodology and involves five basic steps: (1) establishment of a scenario set that covers a range of seismic damage potential in the network, (2) assessment of resilience using various graph-based metrics, (3) topology-based simulations, (4) evaluation of changes in graph-based metrics, and (5) examination of resilience in terms of spatial distribution of critical nodes and the entire network topology. Our case study was from the city of Kathmandu in Nepal, where the earthquake on April 25, 2015, followed by a major aftershock on May 12, 2015, led to numerous casualties and caused significant damage. Therefore, it is a good example for demonstrating and validating the developed methodology. The results presented here indicate that the proposed approach is quite efficient and accurate in assisting stakeholders when evaluating the resilience of transportation networks based on their topology.     

Embedding resilience in emergency resource management to cope with natural hazards

Natural Hazards - Emergency resource management, as a critical way of decreasing loss from natural hazards, has encountered some deficiencies in practice. The purpose of this paper is to develop...     

Spatial and temporal evolution of community resilience to natural hazards in the coastal areas of China

With the accelerating progress of industrialization, urbanization and population growth in recent decades, community resilience, the ability of communities to function effectively and recover successfully in the aftermath of disasters and shocks, has received great attentions. A number of studies had been conducted focusing on community resilience. This article applied community resilience framework to the coastal areas of China, which are the most densely populated and economically developed areas in China with the most frequent marine disasters. City-level social and economic data were used to construct a community resilience index (CRI). Using factor analysis and the global principal component analysis method, 55 city-level indexes were reduced into 15 factors that explain 73.99% of the variance. Getis–Ord G* Statistics were used to depict the high-value clusters and low-value clusters of the CRI. Clearly identified spatial and temporal variations of the CRI showed that both the overall level and regional differences of the CRI increased from 2003 to 2013; the overall spatial agglomeration characteristic of community resilience was not significant. Our findings also highlighted the key elements to improving community resilience: a robust and developed economic system; excellent education programs and training to improve consciousness on disaster prevention and mitigation; adequate investment on critical infrastructure, especially transportation and communication; proper environmental policies to protect ecosystems and water rouses; and extra attention and disaster risk budgets for vulnerable populations.     

Organizing social resilience in the context of natural hazards: a research note

Organizational scholars increasingly use the term “resilience” to analyze options of dealing with uncertain context conditions. What do these scholars have to offer to researchers in the field of natural hazards? This research note makes three suggestions. First, the research note frames social resilience—in contrast to a rigid response to radical change—as a process of broadening information-based activities, loosening formal controls, and using slack resources of organizational members. Second, the research note argues to leave the meaning of social resilience undefined at the outset of a research project with the aim of building theory about resilience. It is expected that a useful definition emerges in empirical research. Third, organizational studies highlight specific social structures and processes of social resilience, for instance, small groups of individuals in organizational and interorganizational contexts. Organizing becomes a crucial factor for dealing with natural hazards.     

Risk-based resilience concentration assessment of community to seismic hazards

Natural Hazards - Risk and resilience assessments have been both widely, but separately, used as tools for guiding policymakers to formulate disaster-risk reduction policies. On the one hand, risk...     

Building resilience to natural hazards in Indonesia: progress and challenges in implementing the Hyogo Framework for Action

Over the last 50?years, the cost of natural disasters has increased globally and in Indonesia (EM-DAT 2012). We therefore need more systematic efforts in trying to reduce disaster risks. In 2005, the United Nations International Strategy for Disaster Reduction created the Hyogo Framework for Action (HFA) 2005?C2015: ??Building the Resilience of Nations and Communities??, in order to enable a more systematic planning, implementation and evaluation of disaster risk reduction (DRR) activities. In this paper, we examine Indonesia??s success in improving DRR by reviewing the country??s progress in implementing the HFA Priorities for Actions. This includes an analysis of the drivers, challenges and emerging issues in building resilience to natural hazards. The study is undertaken through literature reviews and interviews with 26 representatives of key organisations in DRR and climate change adaptation (CCA) in Indonesia. Our findings indicate that the building disaster resilience in Indonesia has been, to a large extent, driven by the existence of the necessary regulatory policies and frameworks and the participation of various non-government stakeholders. Impediments to process include a lack of capacity and capability for DRR at the local government level, a lack of systematic learning and a lack of commitment from government to mainstream DRR into broader development agendas. Emerging pressing issues that are likely to challenge future resilience building activities include the integration of DRR and CCA and urban risk governance.     

Earthquake hazards and community resilience in Baluchistan

Resilience is widely used from a variety of research perspectives; however, community resilience in particular is applied to a number of natural hazards and disasters-related studies, programs, and activities. It is also acknowledged that its measurement is cumbersome but not impossible. The prime objective of this paper is to measure the community resilience of an earthquake-prone area in Baluchistan. The article presents the concept of resilience, its approaches, selection of indicators, formulation of subjective assessment method for weighting the indicators, and finally, developing the community resilience index. For the community resilience measurement, a survey was conducted among 200 households in two earthquake risk zones of Quetta city, using simple random sampling method. The overall composite community resilience index revealed that the resilience is low in both the zones??A and B. However, it is revealed that there is a significant difference between the zones when compared against the components and indicators. Community resilience components such as economic, institutional, and physical have received higher index values in Zone B as compared to Zone A. Based on the findings, it is recommended to improve the socioeconomic, institutional, and structural (housing) conditions of the community by raising the community awareness and preparedness, implementing building codes, and providing income-generating activities in order to enhance the community resilience to cope up with earthquake hazards in the future.     

Time-clustering of natural hazards

Natural hazards can be represented as point processes that are characterized by the occurrence times of the events and their intensities. It is crucial to investigate the correlation properties of these processes in order to gain a deep knowledge of the dynamical mechanisms which underlie hazardous phenomena. To this end, suitable methodologies must be developed to perform these correlation analyses on processes, which are described as point-like processes. The concept of time-clustering implies a time-structured organization of these processes, and is in direct opposition to the pure randomness typical of Poissonian processes in which the events are uncorrelated. This article reports several examples of natural hazards within the framework of time-clustering.     

Resilience to natural hazards: a geographic perspective

Resilience is increasingly used as an approach for understanding the dynamics of natural disaster systems. This article presents the origin of resilience and provides an overview of its development to date, which draws on the wide literature on ecological science, social science, social–environmental system and natural hazards. From a geographic perspective, the model of disaster resilience of “Loss–Response” of Location (DRLRL) was created and disaster resilience was defined from three dimensional mode, which focused on the spatial, temporal scale of resilience and attributes of hazard-affected bodies. A geographic approach was put forward to measure the disaster resilience, including two properties of inherent resilience and adaptive resilience and a case study was implemented in order to validate this approach. This perspective would offer greater potential in application of resilience concept, especially in the process of integrated risk management and disaster recovery.     

A network model to assess base-filter combinations

Granular filters retain base material within the narrowest constrictions of their void network. A direct comparison of the base material particle size distribution (PSD) and the filter constriction size distribution (CSD) cannot easily be used to assess filter-base compatibility. Here a conceptually simple random-walk network model using a filter CSD derived from discrete element modelling and base PSD is used to assess filter-base compatibility. Following verification using experimental data the model is applied to assess empirical ratios between filter and base characteristic diameters. The effects of filter density, void connectivity and blocking in the first few filter layers are highlighted.     

An NGO disaster relief network for small and medium-scale natural hazards in China

Natural Hazards - As China is one of the world’s most vulnerable countries to small and medium-scale natural hazards (SMNHs), its NGOs have had a great deal of experience in dealing with...     

The use of natural analogues to assess radionuclide transport

Predicting the long-term safety and performance of a repository for intermediate- to high-level radioactive wastes requires the evaluation of various scenarios which may influence the integrity of the repository system. One such scenario, radionuclide transport, is described, and some of the geochemical processes which serve to enhance or retard transport are illustrated with examples selected from natural analogue or natural system studies. These studies, as distinct from laboratory simulations, help considerably in understanding how near- and far-field radionuclide transport mechanisms work over geological timescales (thousands to hundreds of thousands of years), more in line with the anticipated lifespan of a repository.

Processes addressed include: stability of the spent fuel UO₂ matrix; bentonite backfill as a barrier to radionuclide diffusion; retention of radionuclides by absorption on fracture minerals; transport and diffusion of radionuclides controlled by interconnected bedrock porosity; geochemical influence and behaviour of repository construction materials on radionuclide transport.     

Indicators of road network vulnerability to storm-felled trees

In this paper, we exemplify the use of simple indicators of wind storm vulnerability of the road network that can be derived from existing geographic datasets. We point out the possible utilization of the datasets, applying GIS techniques, for highlighting road sections that, due to adjacency of high forest stands, are sensitive to closure by storm-felled trees. Indicators reflecting the reduced access to different areas or to the population in need of emergency aid can be derived based on the parameter tree height along roads and road network analysis. As a case in this study, the methodology is applied to elderly people (+80 years) with possible need of daily care at home following a severe storm. A comparison to the extreme 2005 storm felling in southern Sweden reveals that only limited estimates of road network disruption due to storm-felled trees are possible using the indicators, as other factors, for example, wind direction, which determine the exact impact of a particular storm are not taken into account. However, the indicators and network analysis also provide a possibility to draw attention to locations where disruptions of the road network would have significant effects on the accessibility to large surrounding areas. Potential critical road closures can be identified and preventive measures considered locally at these points.     

Large-scale vulnerability assessments for natural hazards

This article examines the process by which vulnerability analysis takes place at the state level for State Hazard Mitigation Plans, as required by the Disaster Mitigation Act of 2000. The methods developed by the Center for Hazards Research and Policy Development at the University of Louisville are described, followed by a brief discussion on issues and challenges. A key finding in this article is the need to understand the impact and role of vulnerability analysis on planning and policy-making at the state and local level, as it applies to the investment of funding and resources in hazard mitigation. Recommendations for policy as well as directions in future research are offered in conclusion.     

Modelling forest resilience in Hindu Kush Himalaya using geoinformation

Resilience is the capacity of an ecosystem to absorb disturbance and undergo change while maintaining its essential structure, functions, identity and feedbacks. The forests of the Hindu Kush Himalayan (HKH) region are vulnerable to both natural and anthropogenic changes, and the forest land conversion and degradation. Using satellite-derived tree canopy cover percent data and precipitation as the explaining variable, we studied the forest cover resilience in a geospatial framework employing the logistic regression and polynomial equation fitting. Out of the \(4.3\,\hbox {million km}^{2}\) geographical areas, \(873{,}650\,\hbox {km}^{2}\) (20.20%) was under the forest in 2000 and experienced loss of \(11{,}250\,\hbox {km}^{2}\) during 2000–2010. We could model the forest cover and treeless areas fairly than the scrub and grassland owing to the variation in precipitation pattern. The majority of the forest cover (59.3%) has been estimated to have less resilience owing to the receipt of <1650 mm of total annual precipitation, whereas only \(375\,\hbox {km}^{2}\) forest area could change to scrub that shows the least resilience. About 94.4% of treeless areas were estimated to be stable, while only 1% \((25{,}200\,\hbox {km}^{2})\) area could accommodate the grassland. The resilient forest areas estimated and observed, owing to the mapping and modelling protocols used in this study, shall be useful in conservation planning in the HKH region.