Characteristics of US drought and pluvials from a high‐resolution spatial dataset

Abstract

AbstractAnomalous precipitation can be a devastating natural disaster having significant impacts on economies, society and the environment. This study examines the spatial and temporal characteristics of anomalous precipitation throughout the United States to obtain a greater understanding of drought/pluvial regimes, including intensity, duration and spatial coverage based on a high‐resolution precipitation dataset. With the help of the parameter‐elevation regression on independent slopes model (PRISM), approximately 4 km data for the United States is used to construct the Palmer drought severity index (PDSI) and the standardized precipitation index (SPI) for the period 1895–2003. Increased resolution from the PRISM dataset shows that drought/pluvial areas are not as homogeneous as seen in previous studies based on climate divisions and larger scales. While size, duration and locations of drought/pluvial events are influenced by the index used, the largest annual drought/pluvial events occur more frequently in the central United States, with a higher percentage of extreme values occurring in the western portion of the country. Four large pluvial events have occurred in the United States during the study period, with three of these having occurred during the past 30 years. Copyright © 2007 Royal Meteorological Society