HR: 08:00h
AN: G21D-01 INVITED     [Abstracts]
TI: Characterizing and Monitoring Drought in the 21st Century--Issues and Opportunities
AU: * Brown, J F
EM: jfbrown@usgs.gov
AF: SAIC, USGS/Earth Resources Observation and Science, 47914 252nd Street, Sioux Falls, SD 57198 United States
AB: Droughts originate from precipitation deficiencies resulting in water shortages that affect certain activities or sectors. Since droughts are normal climate phenomena, society has been dealing with their related impacts and consequences for many centuries. Historically, reliable observations of rainfall have been available for about two hundred years, and most meteorological drought indicators incorporate this variable, either alone or combined with other measures. Traditionally, surface observation networks have been the primary sources for drought information. However, common limitations of climate indicators derived from ground-based networks include large gaps in coverage and coarse spatial detail. In addition, decision-makers need information concerning the effects that drought may be having on certain human and natural systems. Specific examples of these effects include declining forage production, lower crop yields, increased wildfire danger, deteriorating soil conditions, diminishing water supplies, and limits on recreation. Droughts differ from other natural hazards in several significant ways. They may be gradual or "creeping" in their development (on the scale of weeks or months, not days). They can last for periods of years and exhibit large variability in both spatial extent and severity. Monitoring and predicting drought conditions are necessary activities of government agencies at State, Federal, and local levels as part of decision support for planning, risk management, and hazard mitigation activities. Satellite remotely-sensed data providing large-area synoptic coverage and finer spatial resolution can fill in the gaps, reinforce, and complement the science framework for characterizing, monitoring, and predicting natural hazards. Earth observations from remote platforms have a unique role to provide information pertinent to all hazards. For drought science, examples of key data sets include satellite rainfall estimates, albedo measurements, soil moisture measurements, vegetation and canopy moisture indices, and surface temperature. Although there have been some barriers to the wholesale embracing of remotely-sensed data for drought science, there are many examples where these data and related technologies have supported and enhanced drought studies and decision-making. Some of the earlier barriers include immaturity of science instruments, the support of operational systems, error and noise reduction, and validation. A new drought indicator based on both remotely-sensed and direct observations called the Vegetation Drought Response Index (VegDRI) is the result of ongoing drought monitoring research jointly conducted by the National Drought Mitigation Center (NDMC), the High Plains Regional Climate Center, and the U.S. Geological Survey's EROS Data Center (EDC). The VegDRI has been produced in a research environment using a classification and regression tree technique that integrates information from climate and satellite databases. The indicator is a unique source of information for monitoring drought effects on vegetation in natural and anthropogenic landscapes and the output products contain sub-county level detail not previously found in existing climate-based drought indicators. Future efforts will be directed toward developing an operational system for the conterminous U.S., further validation of the output, and integration of this index into drought decision-support systems.
DE: 0429 Climate dynamics (1620)
DE: 0480 Remote sensing
DE: 1655 Water cycles (1836)
DE: 1812 Drought
DE: 3354 Precipitation (1854)
SC: Geodesy [G]
MN: Fall Meeting 2005