Indices and Methodologies for Monitoring Droughts: A Review

Abstract

The present work is a bibliographic review and addresses the main indexes used in the monitoring and analysis of droughts. In addition, the text also discusses the methodologies utilized worldwide in monitoring and forecasting these events. Droughts occur when there is a rainfall deficit compared to the region's historical average. They can be diagnosed by means of indices that identify periods of scarcity or availability hydric through equations. In this way, it is possible to determine the intensity, frequency, and duration of drought events. In this context, some countries have implemented their own drought monitoring and early warning systems such as the United States Drought Monitor, Europe's Drought Monitor and Brazil's Drought Monitor. Where they use information from indexes together or in isolation, in order to identify and characterize drought events. Thus, there can be better planning by the responsible institutions, adoption of emergency plans and mitigation of impacts.

Keywords
precipitation; water resources; drought monitor