Analysis of social vulnerability of residential community to hazards in Tianjin,China

Flood management consists many aspects such as hazard assessment, vulnerability assessment, exposure assessment, risk assessment, early warning system, damage assessment as well as risk mitigation planning. Conventional flood management are depending on the ground based monitoring of rainfall and river discharge. Many parts of the world are not covered by these sensor networks in one hand and these ground based systems are costly. Most of the tropical countries have high flood risk and low financial and institutional capacity to afford ground based system. While conventional flood management is time and cost intensive, spaceborne remote sensing provides timely and low-cost data in comparison to field observation, and is the obvious choice for most developing countries affected by flooding. Many aspects of flood management are being aided with the advancement of remote sensing technology. More precise and near real time flood detection, lead time in flood early warning system, accurate and advance inputs of hydrological models are now blessed by space technology. Many methods and approaches have been developed to overcome the constrains in the application of spaceborne remote sensing in flood management. Application of satellite remote sensing in flood hazard assessment is well documented, however, the application of space technology in other aspects of the flood management is also promising. Therefore, this review paper focuses on the applicability of spaceborne remote sensing and in most of the aspects in flood management.

     

Interaction between land-use change,flooding and human health in Metro Vancouver,Canada

Many regions of the world are experiencing an increase in frequency and intensity of floods. There has been increasing understanding among emergency preparedness and natural disaster planners that rapid urbanization is enhancing the risk from river flooding in urban areas. Many regions of Canada have been exposed to particularly severe floods over the course of the last few years, much of this due to land-use change. This study aims at understanding the risk of flooding for the City of Metro Vancouver, British Columbia, Canada, which is located in the Fraser River Delta. The paper presents a fast, efficient and reliable method that can be used to produce vegetation maps from advanced very high resolution radiometer images and SPOT vegetation maps. A 10-day maximum normalized difference vegetation index maps were produced to assess the dynamics of the urbanization process in Vancouver. Remotely sensed data show a significant decrease in vegetation cover in the Metro Vancouver City between 1984 and 2012. The proposed method can be used as an effective tool for raising early land-use change awareness and assist with flood risk management. Flood risk management has a substantial impact on human health and well-being in urban areas, and this flood risk information will be used to assess the impact of flooding and explore the complex relationship between land-use change, urbanization, flooding and impact on urban dwellers.     

Household vulnerability and resilience in flood hazards from disaster-prone areas of Punjab,Pakistan

Natural Hazards - An environmental variation has caused Pakistan an alarming portrait of vulnerability in flood disasters. The government has focused on a number of realistic actions, heartening...     

Waterlogging and flood hazards vulnerability and risk assessment in Indo Gangetic plain

The recurrent flooding during monsoon and subsequent waterlogging in the northern Bihar plains and the magnitude of losses due to these hazards indicate the continuing vulnerability of the region to flood and waterlogging. Management of floods and waterlogging hazards in highly flood-prone regions of India, including Bihar state has been largely response oriented with little or no attention to mitigation and preparedness. This paper presents a method for spatial, Geographic Information Systems-based assessment of flood and waterlogging vulnerability and risk in northern Bihar plains. Multitemporal satellite data was used to evaluate the area statistics and dynamics of waterlogging over the period from 1975 to 2008. The flood proneness is evaluated at district level with reference to flood inundation during a period from 1998 to 2008. Census data were used to examine the socio-economic characteristics of the region through computation of population density, cultivators, agricultural labourers, sex ratio, children in age group 0–6 years and literates. The geohazard map derived by combining area prone to waterlogging and flood inundation was multiplied with socio-economic vulnerability map to derive the flood-waterlogging risk map of the region. The result shows that flood and water-logging pose highest risk to the central districts in the northern Bihar plains with 50.95% of the total area under high and very high risk.     

Analysis of social vulnerability to hazards in China

To improve natural disaster management, it is important to recognize the variability of the vulnerable populations exposed to hazards and to develop location-based emergency plans accordingly. This paper presents a mathematical model to establish a model of social vulnerability index (SoVI), which includes 12 social variables, and the regional social vulnerability to natural hazards was formulated by them. Taking a city as statistical unit, the variability of vulnerability to natural hazards was explored among the 323 cities based on the SoVI. The results indicate that vulnerability is a location-based regional phenomenon, with the most vulnerable cities being located in the southwest of China and the eastern areas being generally less vulnerable. The results will be helpful for policy makers to formulate disaster management plans, which can be beneficial for people in more vulnerable areas who are responding to, coping with, and recovering from natural disasters.     

An approach for measuring social vulnerability in context: The case of flood hazards in Muzarabani district,Zimbabwe

Understanding the complexity of vulnerability to disasters, including those triggered by floods, droughts and epidemics is at the heart of disaster risk reduction. Despite its importance in disaster risk reduction, there remains a paucity of approaches that contribute to our understanding of social vulnerability that is hidden in dynamic contextual conditions. The study demonstrates an accessible means to assessing the spatial variation of social vulnerability to flood hazards and related for the context of Muzarabani district in northeast Zimbabwe. The study facilitated local identification with residents of variables contributing to social vulnerability and used the principal component analysis (PCA) technique to develop a social vulnerability index (SoVI). Using ArcMap10.2 geographic information systems (GIS) tool, the study mapped composite SoVI at the ward level. The results showed that Muzarabani district is socially vulnerable to hazards. The social vulnerability is influenced by a variety of economic, social and institutional factors that vary across the wards. Quantifying and visualising social vulnerability in Muzarabani provides useful information for decision makers to support disaster preparedness and mitigation programmes. The approach shows how spatially distributed multivariate vulnerability, as grounded in interpretations at local level, can be quantitatively derived for contexts such as those of Muzarabani. The study findings can inform disaster risk reduction communities and cognate disciplines on quantitative assessments for managing hazard vulnerability where these have hitherto not been developed.     

The vulnerability of the elderly to hurricane hazards in Sarasota, Florida

Although the elderly are commonly thought to be disproportionately vulnerable to natural hazards, the elderly populations of coastal communities are continuing to grow. Because there is little to no empirical hazards work specifically addressing the vulnerable elderly in coastal communities, this paper uses Sarasota County, Florida, as a case study to analyze how vulnerable the elderly are to hurricane hazards and whether all elderly people are equally vulnerable. To explore the spatial variations in degree and composition of vulnerability among this population, the analysis maps physical exposure to hurricane storm-surge inundation and precipitation-induced flooding and creates social vulnerability indices by applying principal components analysis to census block group data in a geographic information system. The results show that elderly inhabitants of barrier islands face a considerable physical threat from hurricane-induced storm surge and flooding but are less socially vulnerable because of their wealth; the elderly living inland are far less physically vulnerable but are poorer and consequently demonstrate high socioeconomic sensitivity and limited adaptive capacity to these hurricane hazards. The paper concludes that the elderly are not equally vulnerable: there are many different types of elderly living in many different locations, and their vulnerability varies by type and over space. Effective vulnerability reduction measures should account for these differences between the elderly populations.     

Assessing social vulnerability to biophysical hazards in the Kumasi metropolis,Ghana

This study assesses social vulnerability to hazards by analyzing the nature of biophysical hazards, and the characteristics of exposures, susceptibilities and adaptive capacities in Kumasi. A mixed method approach was used to collect primary data from farms and nearby markets. Water, soil, and plant samples were collected and tested for total coliforms and cadmium. Primary dataset was also collected from farmers and vendors using structured interview guide and from key informants through in-depth interviews. The analysis shows that several pressures residing within the coupled social-ecological system are threats to the health and livelihood of the farmers and vendors. The concentration of cadmium and total coliform in irrigation water, soil, and plants exceeded the WHO/FAO acceptable standards. Bio-toxins in plants were also found to be potentially high. However, the degree of exposure to these stressors and the strength of response and adaptive capacities were determined to be dependent on position within the urban agriculture value chain, type of plant, and socio-demographic characteristics. The study concludes that pollution of irrigation water, soil, and plant is an issue of environmental concern in the urban agriculture system and requires concerted efforts of all stakeholders to address. It is recommended that there should be frequent monitoring of the quality of irrigation water, soil, and produce from urban farms and markets to assess their physical, chemical, and microbial properties and possibly initiate remedial measures where necessary. Government policies must also focus on building the resilience of urban farmers and vendors to reduce their vulnerability to biophysical hazards.     

Vulnerabilities to flood hazards among rural households in India

Natural Hazards - Flooding constitutes the most predominant natural disaster in India. The degree and causes of vulnerability to flood risk vary by society, geographical region and over time. The...     

Modelling the flood vulnerability of deltaic Kuching City,Malaysia

The main objective of this writing is to present a practical way to envisage the flood vulnerability in deltaic region, particularly on the concern of sea level rise. Kuching city of Malaysia is established on banks of Sarawak River, 30 km from the sea. Therefore, it is subjected to fluvial and tidal floods. Kuching Bay experiences the highest King Tides in Southeast Asia region. These tide magnitudes could be a glimpse of future sea level rise. By means of modelling these tides, it provides an understanding and preparation for the impacts of sea level rise on the flood mitigation infrastructures and the city itself. The modelling efforts had created an illustration that a 10% rise in tide levels would result in increase of flooding areas up to 6% relative to existing tide levels.     

Variations in population vulnerability to tectonic and landslide-related tsunami hazards in Alaska

Natural Hazards - Effective tsunami risk reduction requires an understanding of how at-risk populations are specifically vulnerable to tsunami threats. Vulnerability assessments primarily have been...     

The vulnerability of the European air traffic network to spatial hazards

The 2010 eruption of the Eyjafjallajökull volcano had a devastating effect on the European air traffic network, preventing air travel throughout most of Europe for 6 days (Oroian in ProEnvironment 3:5–8, 2010). The severity of the disruption was surprising as previous research suggests that this type of network should be tolerant to random hazard (Albert et al. in Nature 406(6794):378–382, 2000; Strogatz in Nature 410(6825):268–276, 2001). The source of this hazard tolerance lies in the degree distribution of the network which, for many real-world networks, has been shown to follow a power law (Albert et al. in Nature 401(6749):130–131, 1999; Albert et al. in Nature 406(6794):378–382, 2000). In this paper, we demonstrate that the ash cloud was unexpectedly disruptive because it was spatially coherent rather than uniformly random. We analyse the spatial dependence in air traffic networks and demonstrate how the combination of their geographical distribution and their network architectures jeopardises their inherent hazard tolerance.     

Gravelly flood deposits of Irvine Creek, Ontario, Canada

In May 1974 a powerful flood flushed the Grand River basin, Ontario. The effects on the bedload were drastic in a narrow (30 m) and deep (40 m) rock walled and floored gorge near Elora, Ontario. Along Irvine Creek, the tributary occupying the gorge, the gravel cover was reworked in several types of bars, predominantly transverse and point bars. The bars formed very rapidly in response to essentially steady, non-uniform flow that developed during a brief period of high flood. Superimposed on major bars are several minor sedimentary features such as coarse transverse ribs, chute channels and bars, longitudinal ribs, imbrication clusters, backsets with well developed imbrication, that were formed under very high stream discharge. Structures like imbrication clusters, transverse ribs and small riffle bars require a ‘live bed’ situation to form, and they develop when stones come to a stop either because they cluster during transport, or because keystone effects occur along shallow channels. In Irvine Creek, very few sedimentary features were formed during waning and low flood stages: only some shadow deposits and a few Ostler lenses. The few fines that were available were lost downstream or filled in lower parts of gravel beds. This study confirms that in streams that experience strong seasonal fluctuations in discharge, bedforms that develop during high floods have a high probability of preservation. In gravelly deposits, foreset structures and plane beds are most commonly preserved, although they may be difficult to recognize in old deposits, which may appear massive, particularly if the gravel has been infilled with finer pebbles and sand. In the case of Irvine Creek, all deposits are organized, and lateral and vertical variations in textures, particularly imbrication and packing, are very useful in the recognition of sedimentary structures.     

Spatial scan statistics in vulnerability assessment: an application to mountain hazards

In the European Alps, the concept of risk has increasingly been applied in order to reduce the susceptibility of society to mountain hazards. Risk is defined as a function of the magnitude and frequency of a hazard process times consequences; the latter being quantified by the value of elements at risk exposed and their vulnerability. Vulnerability is defined by the degree of loss to a given element at risk resulting from the impact of a natural hazard. Recent empirical studies suggested a dependency of the degree of loss on the hazard impact, and respective vulnerability (or damage-loss) functions were developed. However, until now, only little information is available on the spatial characteristics of vulnerability on a local scale; considerable ranges in the loss ratio for medium process intensities only provide a hint that there might be mutual reasons for lower or higher loss rates. In this paper, we therefore focus on the spatial dimension of vulnerability by searching for spatial clusters in the damage ratio of elements at risk exposed. By using the software SaTScan, we applied an ordinal data model and a normal data model in order to detect spatial distribution patterns of five individual torrent events in Austria. For both models, we detected some significant clusters of high damage ratios, and consequently high vulnerability. Moreover, secondary clusters of high and low values were found. Based on our results, the assumption that lower process intensities result in lower damage ratios, and therefore in lower vulnerability, and vice versa, has to be partly rejected. The spatial distribution of vulnerability is not only dependent on the process intensities but also on the overall land use pattern and the individual constructive characteristics of the buildings exposed. Generally, we suggest the use of a normal data model for test sites exceeding a minimum of 30 elements at risk exposed. As such, the study enhanced our understanding of spatial vulnerability patterns on a local scale.