Droughts - Extreme Events: A Physical Reconstruction and Risk Assessment - page 50

over the long term, display 400 year periodicities. These aspects of the drought
regime cannot be recognised from short historical records alone. Indeed, to
assume that the historical record is a realistic reflection of the nature of this
hazard would clearly lead to a gross underestimate of community vulnerability
and exposure. The long-term drought records highlight the importance of com-
plementing short historical records with long-term natural archives to gain an
understanding of the possible impacts of this hazard in the future.