Developing drought triggers in complex water systems: The WARGI approach

Abstract: Drought is a creeping phenomenon, making its onset and end difficult to determine. The socioeconomic effects of drought accumulate slowly over a considerable period of time, and may linger for years after the termination of the event. Technological change is improving our ability to manage water more effectively and can facilitate the shift from crisis management approach to risk management approach. If they become part of a comprehensive early warning system, these advancements can provide decision makers with better and more timely data and information. Particularly in water resource systems, that frequently experience severe drought events, the definition of pro-active drought mitigation measures becomes a central aspect in the systems planning and management. Decision support systems (DSS) can be used to aid water authorities to provide information and improved understanding that may eventually lead to improved system design and management. The effectiveness of an early warning system integrated in the DSS depends on its drought indicators and triggers. The absence of a precise definition of drought indicators and triggers has led to indecision and/or inaction on the part of policy makers, water authorities, stakeholders and others. To provide an overall process and specific methodologies for the definition of drought mitigation measures and the effective linking of these measures with triggers, Sechi and Sulis (2007) recently developed a full integration of th