DROUGHT AS A NATURAL DISASTER

Droughts are major natural disasters for many parts of the world. Dry areas, where the precipitation pattern is markedly seasonal, or is oth erwise highly variable, are the most susceptible. The Canadian Prairie s, together with the U.S. Great Plains, are one such area. While immed iate loss of life is seldom a feature of most droughts, malnutrition a nd even starvation do follow severe droughts in some parts of the worl d. In Canada, economic losses, particularly in the agricultural sector , may reach several hundred millions of dollars in a drought year, wit h major socio-economic repercussions affecting the entire region. Envi ronmental damages include soil degradation and erosion, vegetation dam age, slough and lake deterioration and wildlife loss. Unlike most othe r natural disasters, drought onset is difficult to identify. Droughts develop slowly, and until human activity begins to be affected by an o n-going reduction of precipitation, their existence is unrecognized. D evelopment and application of specific soil moisture and drought indic es based on cumulative precipitation deficits have enhanced drought mo nitoring programs. These in turn provide guidance on the need for miti gative measures that can be initiated early in the course of a drought . Any improvement in the timely application of these measures is, howe ver, strongly dependent on being able to determine the drought's cours e, extent and likely severity at the earliest stage possible. The iden tification of precursor conditions for past drought has raised the pos sibility that the likelihood of a drought occurring in a particular ye ar or growing season might be predictable. Teleconnections between Nor th American precipitation patterns and ENSO events and other surface b oundary conditions in the North Pacific have been detected. Forecastin g seasonal temperature and perhaps precipitation anomalies appears to be potentially feasible using a suitable merging of precursor paramete rs and modelling methodologies. Clearly, future research must focus bo th on those precursors that have been identified and on a search for p ossible new ones. Development of better forecasting methodology is als o essential. Research activity to identify and evaluate new mitigative measures should also be increased to keep pace with the prospects of drought predictability.