Drought is a natural disaster that influences many aspects of society. Since the demand for water is increasing along with the population in many parts of the world, water supply interruptions caused by drought can be expected to produce greater impacts. This is because the impacts of drought are determined not only by the frequency and intensity of meteorological drought but also by the number of people at risk and their degree of risk (Wilhite, 2000). For example, the increase in population in Africa and Asia increases drought vulnerability significantly. Thus, policies that promote the development and implementation of appropriate drought mitigation measures today will help to reduce the economic, social, and environmental impacts associated with future droughts and the need for government intervention. To monitor drought, different types of indicators (e.g., drought indices) have been used in many parts of the world. Because there is no single definition for drought, determining which indicators to use poses more difficulties for planners. Decision makers use different policies and strategies based on the historical records of their countries. For example, in Australia, when meteorological drought (annual rainfalls in the lowest 10% of recorded values) occurred over at least 10% of the continent, it coincided with damaging agricultural droughts resulting significant losses of crops and livestock (Heathcote, 2000). Because of the varied and potentially catastrophic losses resulting from drought in many parts of the world, both governmental and non-governmental decision makers need better predictive and monitoring tools to assist them in dealing more effectively with drought. Better early warning and prediction is the foundation of a new drought management paradigm based on risk management. In South Africa, the Weather Bureau issues extended outlooks for short and long periods using numerical modeling and statistical methods (Vogel, Lang, & Monnik, 2000). In United States, recent advances in science and technology are enhancing drought monitoring capabilities and the availability of such information, which allows decision makers to make more knowledge-based decisions to lessen the impacts of drought. In this article, we highlight the role of government in drought planning and mitigation, the potential of data mining techniques and their outputs (e.g., maps and tables) for improving informed decision making, and also present a newly developed drought monitoring tool, the Vegetation Drought Response Index (VegDRI) as an example over the central United States.
Sustainability Monitoring: Principles, Challenges, and Approaches