Search USGS⌕ Search
Home/Archive/USGS

USGS · 70013882

The Palmer Drought Severity Index: limitations and assumptions.

W.M. Alley
View original source ↗Export metadata ↓

Abstract

The structure of the Palmer Drought Severity Index (PDSI), which is perhaps the most widely used regional index of drought, is examined. The PDSI addresses two of the most elusive properties of droughts: their intensity and their beginning and ending times. Under certain conditions, the PDSI values are very sensitive to the criteria for ending an 'established' drought and precipitation during a month can have a very large effect on the PDSI values for several previous months. -from Author

Explore related subjects

Journal of Climate and Applied MeteorologyArticle

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

W.M. Alley. 1984. The Palmer Drought Severity Index: limitations and assumptions.. https://doi.org/10.1175/1520-0450(1984)023%3C1100%3Atpdsil%3E2.0.co%3B2

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS1985

Concentrations and source areas of ice nuclei in the Alaskan atmosphere.

The results indicate a seasonal variation in nucleus concentration with a winter minimum and a north-to-south trend in the increasing average concentration. Some episodes of high concentrations were correlated with 500 mb isobaric transport from Eurasia and 700 mb cyclogenesis over Alaska. These results suggest that local nucleus sources play a dominant role in the seasonal variation, while some individual episodes are caused by external or regional influences. -from Authors

Journal of Climate and Applied Meteorology↗
USGS1985

Streamflow variability in the United States: 1931-1978.

Systematic modes of spatial and temporal variation in a 48-year record of streamflow are defined using principal components. The components were calculated from a matrix of annual streamflow departures for 106 grid cells covering the United States in the years 1931-78. Five statistically significant components are found to account for more than 56% of the total variance. A varimax orthogonal rotation of the original components describes regional anomaly cores located in the middle Mississippi Valley, Pacific Northwest, Far West, Northeast, and northern Great Plains. -from Author

Journal of Climate and Applied Meteorology↗