Thursday, June 18, 2009

Pinpointing drought in the US

US Geological Survey: Take vast quantities of satellite remote sensing data. Season with time. Mix generously with information about climate, soils, and recent rainfall. These are the ingredients for the Vegetation Drought Response Index.

Known to specialists as VegDRI, this computer modeling and monitoring method provides continuous drought information over large regions and supplies finer spatial detail than other commonly used drought indicators. The index is now available at two-week intervals across the conterminous 48 States.

“For anyone monitoring agricultural conditions, particularly ranching, or with interests in natural resource management, VegDRI is invaluable,” said Dr. Brian Wardlow, Remote Sensing Specialist at the National Drought Mitigation Center (NDMC) of the University of Nebraska-Lincoln. “It gives us a regional overview with enough definition to know how specific rangelands and crops are doing.”

VegDRI integrates time-series observations of vegetation with climate, land cover-land use type, ecological setting, and soil characteristics to show drought’s effect on vegetation at a 1-kilometer resolution. The massive remote sensing archives at the USGS Earth Resources Observation and Science Center (USGS-EROS) supply historical satellite data from the last 20 years that are critical in establishing a sound comparison of normal conditions over a longer historical period…

A mute, unnamed master photographer at the US Geological Survey took this shot of a parched wetland. Thank you, whoever you are.

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