system interacts with hazard vulnerability and disaster event characteristics in determining levels of disaster impacts as outcomes of the model. The unity of hazards and disaster research that the committee considers essential is thereby revealed. The interactions among the five core topics of hazards and disaster research—introduced in Figure 1.1 and depicted more pointedly in Figure 1.2’s process model—are important on both theoretical and practical grounds. Both theoretically and empirically, hazard vulnerability, hazard mitigation, disaster preparedness, emergency response, and disaster recovery are mutually related. Indeed, they are components of a highly complex but comprehendible response structure. Practically, collective actions related to these constructs and their interactions increase or decrease the human harm and social disruption of disaster as the committee has defined that term. Thus, research on hazards and disasters has important implications for both basic science and public policy.

Chronological and Social Time

Both chronological time and social time are essential constructs in hazards and disaster research. As depicted in Figure 1.2, chronological time is linear, unidirectional, and readily calibrated using standard physical measurements. Chronological time allows for the partitioning of collective actions by time phases of disaster events (pre-impact, trans-impact, post-impact) and the examination of their interactions. In chronological time, pre-disaster vulnerability assessments influence hazard mitigation and disaster preparedness decisions under more routine, pre-impact circumstances. The trans-impact period constitutes the time immediately prior to and during an actual event when specific hazard mitigation and preparedness interventions are set in motion. Such planned interventions intersect with improvised emergency response and recovery activities during and after the event has occurred. Chronological time is also an essential tool for making comparisons between disasters in terms of such characteristics as frequency, predictability, length of forewarning, and duration of impact.

The scientific value of chronological time is unquestionable and taken for granted. Yet its value for analytical purposes is not unlimited; and thus, Figure 1.2 calls for a complementary treatment of social time. Social time is more complex than chronological time, but the concept is very useful for expressing the singularity of hazards and disaster research. The distinction between chronological and social time has heretofore rarely been mentioned by the hazard and disaster research community (see Forrest, 1993; Quarantelli, 1998:255-256), let alone seriously examined (for a notable exception, see Bankoff, 2004). The committee thinks that the distinction has scientific value and directly informs its work (Zerubavel, 1981, 1997, 2003).

Social time is nonlinear and multidirectional and may be experienced



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