Calculating drought hazard at the country-level in Asia

Drought comes in many forms and time-scales, encompassing hydrologic, agricultural, and meteorological droughts, and disaster reporting can be heavily politicized – so is it possible to find simple links between climatic measures of drought and reported drought disasters? A drought disaster is caused by the combination of both a climate hazard--the occurrence of deficits in rain or snow--and a societal vulnerability--the economic, social, and political characteristics that render livelihoods susceptible in the region influenced by the deficits. As global climate data is operationally monitored and forecast, a regional-to-global scale perspective on the climatic signature of drought disasters could enhance ongoing efforts in drought monitoring, early warning, and mitigation efforts. This investigation undertakes a pilot effort for Asia (including Indonesia and the Philippines) comparing climate-based measures of drought with the incidence of reported drought disasters in the database of the Centre for Research on Epidemiology of Disasters (CRED).

The results demonstrate a correspondence between severe, persistent precipitation deficits as observed in the available climate monitoring data for country averages and reported drought disasters for 14 of the 27 countries considered during the 1979-2001 period -- using a single criteria for all countries. The climate-based drought estimate using a 12-month average of weighted, standardized precipitation matches all reported drought disasters for Israel, Afghanistan, Pakistan, Syria, Armenia, and Malaysia, encompassing 7 matches in total for these countries, with 10 misses (instances of identified climate drought with no disaster report within the following 3 months). Global-scale climate fluctuations in 1982-1983 and 1999-2001 strongly affected the occurrence of wide-spread precipitation deficits in the region and were also reflected in the disaster data, particularly in the later period which encompassed the largest values in both the climate and disaster data. There is some suggestion that, for the estimates considered here, the relationship is more robust in the semi-arid countries. The relationship is present across a wide range of climatic zones, however, from semi-arid to tropical.