HR: 0800h
AN: H11F-0371 [Abstracts]
TI: Hydrologic Drought in the Colorado River Basin
AU: * Timilsena, J
EM: janakti@egr.unlv.edu
AF: University of Nevada, Las Vegas, Department of Civil and Environmental Engineering, Las Vegas, NV
89154-4015
United States
AU: Piechota, T
EM: piechota@ce.unlv.edu
AF: University of Nevada, Las Vegas, Department of Civil and Environmental Engineering, Las Vegas, NV
89154-4015
United States
AU: Hidalgo, H
EM: hhidalgoleon@ucsd.edu
AF: Scripps Institute of Oceanography, Climate Research Division, University of California, La Jolla, CA
92093-0224
United States
AU: Tootle, G
EM: tootleg@unlv.nevada.edu
AF: University of Nevada, Las Vegas, Department of Civil and Environmental Engineering, Las Vegas, NV
89154-4015
United States
AB:
This paper focuses on drought scenarios of the Upper Colorado River Basin (UCRB) for the last five hundred years and
evaluates the magnitude, severity and frequency of the current five-year drought. Hydrologic drought characteristics have
been developed using the historical streamflow data and tree ring chronologies in the UCRB. Historical data include the
Colorado River at Cisco and Lees Ferry, Green River, Palmer Hydrologic Drought Index (PHDI), and the Z index. Three ring
chronologies were used from 17 spatially representative sites in the UCRB from NOAA's International Tree Ring Data. A PCA
based regression model procedures was used to reconstruct drought indices and streamflow in the UCRB. Hydrologic drought is
characterized by its duration (duration in year in which cumulative deficit is continuously below thresholds), deficit
magnitude (the cumulative deficit below the thresholds for consecutive years), severity (magnitude divided by the duration)
and frequency. Results indicate that the current drought ranks anywhere from the 5th to 20th worst drought during the period
1493-2004, depending on the drought indicator and magnitude. From a short term perspective (using annual data), the current
drought is more severe than if longer term average (i.e., 5 or 10 year averages) are used to define the drought.
DE: 1812 Drought
DE: 1833 Hydroclimatology
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting