A GIS-based approach to identify the spatial variability of social vulnerability to seismic hazard in Italy

This paper argues for a multidisciplinary framework to assess the relationship between environmental processes and social sciences that can be adapted to any geographic location. This includes both physical (earthquake hazard) and human (social vulnerability) dimensions in the context of disaster risk reduction. Disasters varies drastically depending on the local context. Indeed, the probability of a natural disaster having more devastating effects in one place than in another depends on the local vulnerability components of the affected society (cultural, social and economic). Therefore, there is an important correlation between the potential risk and the social resistance and resilience of a specific place, thus the disaster response varies according to the social fabric. In this context, the evaluation of social vulnerability is a crucial point in order to understand the ability of a society (studied at individual, household or community level) to anticipate, cope with, resist and recover from the impact of natural disaster events. Within this framework, the paper discusses how it is possible to integrate social vulnerability into the seismic risk analysis in Italy. Specifically, socioeconomic indicators were used to assess and mapping social vulnerability index. Afterwards, a Geographic Information System (GIS) approach was applied to identify the spatial variability of social vulnerability to seismic hazard. Through the use of a risk matrix, the classes of a social vulnerability index map were combined with those of a seismic hazard map proposed by INGV (National Institute of Geophysics and Volcanology). Finally, a qualitative social vulnerability exposure map to an earthquake hazard was produced, highlighting areas with high seismic and social vulnerability levels. Results suggest the importance of the integration of social vulnerability studies into seismic risk mitigation policies, emergency management and territorial planning to reduce the impact of disasters.     

Quantitative Risk Assessment of Catastrophic Debris Flows through Numerical Simulation

The risk assessment is not only the one of the most effective soft measures in natural hazard prevention, but also is the base of hazard risk management. On account of the specificity of various elements at risk and debris flow mechanism, the theoretical system and technical procedure of debris flow quantitative risk assessment for buildings and roads were established in the mountaineous area of Southwest China, which included three sections: ①To represent debris flow hazard quantitatively using the intensity index IDF through FLO-2D simulation; ②To build debris flow physical vulnerability curve based on the loss exceedance-probability from Qipan gully debris flow case; ③To quantify the expected loss of the important elements at risk based on their database after setting the future debris flow scenarios. The case study of Yangling catchment indicated that the responding mechanism between elements at risk and debris flow physical mechanism was described quantitatively by this quantitative risk assessment system, which can contribute to the construction planning and prevention measure making in the southwestern mountainous area.     

Comparative Analysis of Risk Assessment of Landslides and Debris Flows of China in 2000 and 2010

Landslides and debris flows occurr in China frequently and cause disastrous losses of life and property. The risk assessment of landslides and debris flows and their spatial variations were comparatively analyzed in this paper, which has great significance for disaster prevention. This article selected 1 km×1 km grid as the assessment unit and with support of GIS technique, analyzed landslide and debris-flow risk distribution and their spatial variations from 2000 to 2010. The research results indicated that the spatial distribution of risk classes in 2000 and 2010 was obviously discrepant. Overall, taking the Heihe-Tengchong population density line as the boundary, the west of the line is mainly low risk area; the east of the line is mainly high risk area. Compared with the risk of 2000, the risk values of 2010 increased, with the high risk area and low risk area enlarged, moderate risk area reduced. The moderate risk area is the most unstable and sensitive risk area, and its risk class variation is significant. However, China is not a region with the high risk of landslide and debris-flow hazard at present. In the following next 10 years, the risk of landslides and debris flows in China will continue to increase.     

北京突发地质灾害应急避险场所调查评价

结合北京地区突发地质灾害发育特征,提出了应急避险场所调查的内容、方法、工作流程及技术指标等内容,总结分析了北京市应急避险场所的分布、类型、规模、物资储备、建筑形式、路线长度及受灾情况等特征。同时,根据给出的应急避险场所适宜性简易评价方法对全市的应急避险场所进行了系统全面的评价,并针对性的提出了避险防范措施。     

Contamination risk of the Alburni Karst System (Southern Italy)

The Alburni massif (1742m a.s.l.) stretches NW–SE, about 23km long and 9–10km wide, covering 246km² with an average elevation of about 940m a.s.l. This massif, with more than 500 caves, is the most important karst area in southern Italy. The karst channel network is hierarchically organized: some channels feed a major spring (1m³/s) with a very short transit time while others communicate directly with the basal water table related to other springs (Q > 3m³/s).There are several dolines and swallow holes just above the basal water table and in the urbanized areas; for years a swallow hole directly transferred pollutants into the aquifer. The contamination vulnerability map shows that the prevalent vulnerability degree ranges from high to very high, due to the widespread karstification of the area and to the presence, on the plateau, of large vegetated areas with gentle slopes favouring fast infiltration.Hence it is important to ascertain the human impact on the area and the consequent contamination risk of the aquifer of the Alburni karst area. Three main layers were created to assess groundwater contamination risk: the vulnerability map, the hazard map, and the value map.The groundwater contamination risk map stresses the importance in a park area of aquifer vulnerability, which strongly influences the risk: indeed, the prevalent moderate degree of risk in the final map depends on the high vulnerability and the low hazard degree. However, in the future it is crucial to take into account the nature of the agricultural land use allowed in the park, which could increase the hazard degree and consequently the risk degree.     

Environmental impacts of ground vibration induced by blasting at different rock units on the Kadikoy–Kartal metro tunnel

This paper presents the results of ground vibration analysis induced by blasting during the construction of the Istanbul Kadıköy–Kartal metro tunnel. Different rock formations in this tunnel route were encountered during the excavation with blasting. As a first stage, the test site is divided into 6 main regions with respect to lithology changes in the rock units and Hoek's Geological Strength Index value of these rock units. During the excavation, a total of 659 events were recorded in 260 shots by vibration monitors. Scaled distance and peak particle velocity data pairs belonging to these shots were carefully recorded and analyzed statistically. As a result of this analysis, empirical relationships between scaled distance and peak particle velocity were established with higher correlation coefficients specific to each region. Finally, the particle velocities and frequency values of all blast events were evaluated according to Turkish Environmental Regulation, the United States Bureau of Mines (USBM) and the German DIN 4150 Norms in order to predict the influence level to the neighboring buildings and structures.     

Earthquake risk to industry in Istanbul and its management

Istanbul is home to 40% of the industrial facilities in Turkey. Thirty percent of the population working in industry lives in the city. Past earthquakes have evidenced that the structural reliability of residential and industrial buildings in the country is questionable. In the Marmara region the earthquake hazard is very high with a 2% annual probability of occurrence of a magnitude 7+ earthquake on the main Marmara fault. These facts make the management of industrial risks imperative for the reduction of socioeconomic losses. In this paper we present a first-order assessment of earthquake damage to the industry in Istanbul and raise issues for better characterization and quantification of industrial losses and management of urban industrial risks. This paper borrows from the project report entitled ‘Earthquake Risk Assessment for Industrial Facilities in Istanbul’. The full report can be found at http://www.koeri.boun.edu.tr/depremmuh.html under the link ‘Research and Applied Projects’.     

Testing the use of a ‘questionnaire survey instrument’ to investigate public perceptions of tsunami hazard and risk in Sydney,Australia

The Indian Ocean tsunami (IOT) of December 2004 has demonstrated that the coasts of Australia are vulnerable to tsunami flooding. As a consequence of the IOT, the Australian Federal Treasurer announced in 2005 that the Bureau of Meteorology and Geoscience Australia will jointly develop and implement the Australian Tsunami Warning System. Effective response to tsunami warnings is highly dependent on public awareness and perception of tsunami hazard and risk. At present, no efforts have been made to investigate and publish public awareness of tsunami hazard and risk and as such, emergency managers have little idea of the likely challenges to effecting appropriate tsunami risk management. We develop a short questionnaire survey instrument and trial that instrument in order to investigate its suitability for generating information about the perceptions of tsunami hazard and risk in the Sydney region. We found that the design, layout and format of the questionnaire were suitable for our purpose and should be useful for generating information appropriate to emergency management agencies tasked with the responsibility of developing tsunami education campaigns and risk mitigation strategies in Australia. However, certain limitations, such as individual question design and format, should be considered before a much larger survey of various stakeholders is conducted.     

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.     

Evolution of natural risk: analysing changing landslide hazard in Wellington,Aotearoa/New Zealand

This paper addresses the temporal variation of rainfall-triggered landslide hazard within the broader context of natural risk evolution. Analysis of a sequence of aerial photos covering a period of 60 years allowed the establishment of a record of landsliding for a site in the Wellington region, New Zealand. The data show one very dominant peak in the magnitude of landslide occurrence in the late 1970s, followed by a continuous decrease. Landslide hazard can be expressed by the frequency and magnitude of the landslide events, with the total surface area affected used as a surrogate for magnitude. However, the distinct decline of landslide magnitude through time from the 1980s onwards indicates that landslide hazard may change with time. This possibility is further explored by correlating potential landslide triggering storms with the magnitude of the landslide event, using the ‘Antecedent Soil Water Status’ model in combination with daily rainfall. The relation between magnitudes of rainfall and magnitudes of landslide events is found to be weak, suggesting that a given ‘Critical Water Content’ (antecedent soil water status and rainfall on the day) does not produce similar magnitudes of landsliding. Furthermore, the study shows that reactivation of previous landslides before the peak landslide occurrence of the late 1970s is low, while the situation is reversed after this peak and reactivation in the subsequent years plays a larger role. It is concluded that the pattern of landsliding cannot be explained by the pattern of rainfall and other factors are controlling the variation of landslide hazard in time. A possible explanation is a change of the geomorphological system with time, instigated by a massive period of landsliding (the late 1970s peak). Subsequent sediment exhaustion of source areas resulting from this period appears to alter the system’s subsequent reaction to an external trigger such as rainfall. The study demonstrates that landslide hazard analysis in general should not rely on the integral of the frequency–magnitude relationship only, but should include potential non-linear changes of system settings to increase the understanding of future system behaviour, and therefore hazard and risk.