Sorkhabi Earthquake Hazard, Risk and Disasters

1. Auflage 2014
ISBN: 978-0-12-396472-4
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 606 Seiten

Earthquake Hazard, Risk, and Disasters presents the latest scientific developments and reviews of research addressing seismic hazard and seismic risk, including causality rates, impacts on society, preparedness, insurance and mitigation. The current controversies in seismic hazard assessment and earthquake prediction are addressed from different points of view. Basic tools for understanding the seismic risk and to reduce it, like paleoseismology, remote sensing, and engineering are discussed. - Contains contributions from expert seismologists, geologists, engineers and geophysicists selected by a world-renowned editorial board - Presents the latest research on seismic hazard and risk assessment, economic impacts, fatality rates, and earthquake preparedness and mitigation - Includes numerous illustrations, maps, diagrams and tables addressing earthquake risk reduction - Features new insights and reviews of earthquake prediction, forecasting and early warning, as well as basic tools to deal with earthquake risk

Autoren/Hrsg.

Sorkhabi, Rasoul

Leseproben

Chapter 1 Remote Sensing for Disaster Response
A Rapid, Image-Based Perspective
Charles Huyck1, Enrica Verrucci2 and John Bevington2,    1ImageCat Inc., Oceangate, CA, USA,    2ImageCat Ltd., Centrepoint House, Guildford, Surrey, UK Abstract
In the midst of responding to a disaster, emergency managers typically lack actionable information. Remote sensing has the potential to help emergency managers streamline response and recovery by providing: (1) a backdrop of situational awareness—which can be invaluable for assessing likely impacts—and (2) a means to assess the distribution and magnitude of damage. Effective use of remote sensing requires careful selection, acquisition, analysis, and distribution of data and results. Although best practices are often gleaned through trial and error as an event unfolds, the integration of remote sensing techniques in the standard response protocols is far more effective when undertaken outside of response and recovery. This chapter provides practical examples and guidelines for emergency managers and other stakeholders exploring the capabilities of remote sensing in emergency response activities. Keywords
Best practices; Crowd sourcing; Damage assessment; Disaster response; Remote sensing 1.1 Introduction
In the immediate aftermath of a disaster, accurate and timely information is essential for coordinating emergency response activities and supporting early-recovery operations. In these uncertain and pressured times, decision makers are focused on understanding the severity of the event in order to most effectively coordinate response activities. However, information available to decision makers in a disaster's aftermath comes to them as pieces of the puzzle, providing only a partial portrait of the event. Considering the numerous detrimental consequences of uninformed or uncertain decisions on the overall efficiency of disaster response, this lack of information constitutes a great risk for decision makers. With the ability to provide periodic, synoptic observations, images acquired from satellite or aerial remote sensors have the potential to fill the gap in information in the early hours and days of a disaster. Information derived from these images can verify the magnitude and spatial extent of damage in a timely manner and with limited costs. The vast array of techniques that remote sensing technology offers, when used alongside geographical information system (GIS) software, can reduce uncertainty and serve as a catalyzing agent for information acquisition and distribution. In order to convey the full potential of these advanced technologies to date, this chapter provides a discussion of the practical use of remote sensing in support of decision making following natural disasters. This discussion is enhanced by a set of real-world examples of remote sensing and GIS techniques supporting response and early recovery in most of the major disaster events from the past decade. The chapter also describes the main advances in the field, including best practices and acknowledges the limitations of the use of remotely sensed data. 1.2 Remote Sensing and Disaster Response
Following a disaster, a need exists to quickly understand the scope of the event and to initiate and coordinate early disaster response. When suitable preparation is in place, information derived from remotely sensed imagery can establish a common operating picture and allow communication between responders to proceed smoothly and effectively. Remote sensing technologies can be applied extensively to disaster response—starting with early response (e.g., preevent monitoring, early situational assessment) and moving to long-term recovery. Following a simplified timeline (Figure 1.1), this section examines the benefits of using remotely sensed data in the different phases of disaster response. The section also explains which methods and data types are the most suitable for the end objective of each phase.
FIGURE 1.1 Simplified timeline listing possible uses of remote sensing technologies and data to support disaster response. Gray fields are not performed with remote sensing. Fields showing the symbol require a multitemporal acquisition of remotely sensed data. 1.2.1 Early Monitoring and Determination of Preliminary Area of Impact
Determination of the Area of Impact (AOI) consists of an iterative process that starts when an event is approaching (in the case of predictive events, such as hurricanes), when the event occurs (e.g., the main shock of an earthquake) or begins to unfold, and continues until the recovery phase. The preliminary AOI is usually constructed using a fusion of several sources. Media reports (with information posted on social media websites increasingly utilized) and modeled scenario events are the most used sources in the disaster-response field. For earthquakes, the United States Geological Survey (USGS) provides Prompt Assessment of Global Earthquakes for Response (PAGER) and World Agency of Planetary Monitoring and Earthquake Risk Reduction (WAPMERR) provides Quake Loss Assessment for Response and Mitigation (QLARM) alerts. These usually constitute the first source of information available to the public; both provide maps estimating the affected area and are distributed by email, short messaging service, and Twitter as well as posted, respectively, on the USGS and WAPMERR websites. A preliminary AOI can be used to plan and instigate satellite or aerial data acquisition missions. It is common practice to include as wide a region as possible within the preliminary AOI in order to obtain the full-scale variability of the event within the selected boundary/boundaries. For unfolding events, such as fires or floods, multitemporal remotely sensed imagery (imagery captured over the same location at several points in time, usually days apart) can be used to monitor how the event is spreading and aid decision makers in developing and implementing mitigation strategies. For more sudden events, such as earthquakes, remote sensing imagery can provide detailed information before any ground survey can take place, especially in mountainous terrain or in locations with security restrictions, reducing misunderstandings and miscommunications that may arise from a lack of information. Fighting wildfires in the western United States is a compelling example of how response effectiveness increases with remote sensing data monitoring and proper planning. As extensive areas of the region are largely isolated and inaccessible, remote sensing data (either satellite or aerial or obtained by unmanned aerial vehicles) can provide a basis for establishing the AOI and assess burn area, the urban proximity, and the potential human and financial exposure. The final goal of the early assessment phase is essentially to define a boundary that delimits the affected area, so that preliminary information on the event can be generated. Low-resolution data1 (data with a spatial resolution of >30 m) and techniques of automatic extraction are best suited for this purpose. At such an early stage, moderate resolution data (10–30-m spatial resolution), much of which is available free of charge and without restriction, are generally preferred over more costly high (<10 m) or very-high resolution (VHR—sub-1-m) data, the use of which could well be considered a waste of resources. Automatic methods of extraction are also more useful than a detailed analysis as rapidity is the most important factor to take into account at this point of the event response. Disasters that provide warning can be systematically monitored as they progress using multitemporal imagery. Moderate resolution data are invaluable for such events. An example from the 2011 Thailand floods is provided in Figure 1.2.
FIGURE 1.2 Preevent (left) and postevent (right) imageries from the SPOT-5 satellite sensor (Disaster Charter, 2011a). In these false-color images, red areas depict vegetation and urban areas are seen as gray/white areas. The black/green in the postevent image is floodwater spreading from the north. Imagery copyright 2011 Centre National d'Etudes Spatiales. Map produced by the Asian Institute of Technology. 1.2.2 Situational Awareness/Public Awareness
As postdisaster response begins, search and rescue (S&R) activities, logistics planning, and monitoring require careful coordination. At this stage, the need for a detailed representation of the magnitude and the spatial distribution of damage becomes even greater. Remotely sensed data are therefore of great value to the response community at this juncture, adding great detail and accuracy to media-based and modeled estimates of preliminary damage. When acquired and processed in a timely manner, remotely sensed imagery is an ideal resource for conveying the severity of an event to decision makers, local communities, and the wider public. During the period in which data are being prepared for analysis and before damage assessment can start, image data can be used to provide situational-awareness maps and to identify potential cascading effects. In general, responders have found postevent imagery indispensable for situational assessment and public awareness, especially when combined with preevent imagery. Details of an event's impact on specific regions and communities, as well as information about disabled infrastructure and services, provide enough solid information for incident commanders and emergency...