Thematic Note: Cross Cutting Theme: Extensive Risk

This research was funded as part of the Urban Africa: Risk Knowledge programme


The United Nations International Strategy for Disaster Reduction (UNISDR) has led a move to encourage and support governments to greatly improve the accuracy and detail in their records on disasters. One key element of this is the collection of data on ‘small’ disasters and their impacts that do not get included in national and international disaster databases. UNISDR made the distinction between ‘intensive disasters’ (currently when 30+persons killed and/or 600+ houses destroyed) and ‘extensive disasters’ (events recorded as disasters but with impacts below these two thresholds). Drawing data from over 80 countries, UNISDR analyses show the importance of attention to extensive disaster risk both in terms of impact (eg mortality, injury and economic losses) and in terms of what underpins or drives it. What is still unclear is the extent to which extensive risk covers all premature deaths. An important threshold remains separating extensive risk from most everyday hazards that cause premature death or injury – for instance, a flood which kills one person may be included but an infection that kills a three year old child is not. Further, although the UNISDR Global Assessment Reports discuss in some detail disaster loss in urban areas and its underpinnings, the disaster loss data these present are not disaggregated into urban and rural areas.

Urban ARK needs to go further than this in constructing ‘local’ (not national) disaster loss databases (at the level of particular cities or districts within cities) and to consider and document what risks or small disaster events these are not showing (because their impact is too small, because they are not recorded, because they do not fit into the UNISDR disaster categories). By doing this, we will present detailed pictures of risks for urban areas (or particular settlements within urban areas) and move from describing the extent of losses to generating a better understanding of the drivers of risk. This in turn will mean the research is better positioned to respond to recent calls for more local responses to disasters and other crises.

This is an output from the Urban Africa: Risk Knowledge (Urban ARK) programme


Satterthwaite, D., Dodman, D., Pelling, M., ‘Thematic Note: Cross Cutting Theme Extensive Risk’

Thematic Note: Cross Cutting Theme Extensive Risk

Published 1 January 2018