Monitoring Drought: An Evaluation of Meteorological Drought Indices

A uniform method for defining, monitoring and quantifying the severity of drought conditions does not exist. This article introduces some of the tools (e.g. drought indices) that are commonly used in the United States to monitor meteorological drought, describes the strengths and weaknesses of these tools, and makes recommendations about which ones are the most appropriate for measuring and monitoring meteorological drought. The literature and the qualitative drought index evaluation both suggest that the Standardized Precipitation Index and deciles/percentiles are the most suitable for monitoring meteorological drought.