HR: 0800h
AN: H21A-1324    [Abstracts]
TI: Trends and Step Changes in U.S. Streamflow Data
AU: * Piechota, T
EM: piechota@ce.unlv.edu
AF: University of Nevada, Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154-4015 United States
AU: Davies, R
EM: whonnock@earthlink.net
AF: University of Nevada, Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154-4015 United States
AU: Tootle, G
EM: tootleg@uwyo.edu
AF: University of Wyoming, Department of Civil and Architectural Engineering 1000 E. University Ave. , Laramie, WY 82071 United States
AU: Kalra, A
EM: akalra@Egr.UNLV.EDU
AF: University of Nevada, Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154-4015 United States
AB: The study presented here focuses on the changes/trends in U.S. streamflow from 639 unimpaired stations for the period 1951 - 2002. This is particularly relevant since the issue of climate change is of interest to many and studies have also indicated an abrupt change in climate around the year 1976/77. Trends in U.S. streamflow were evaluated using three statistical tests: Spearman's Rho, Mann-Kendall, and Linear Regression. Step changes in the streamflow data were evaluated using the Rank Sum and Student t test. The multiple tests provide robust results in which areas of the U.S. have experienced significant changes in streamflow data. Different quantities of streamflow were evaluated including seasonal and annual data, and changes in the timing of peak runoff. In addition, the changes in droughts and floods were evaluated based on the number of stations experiencing conditions < 25th percentile or > 75th percentile in any given year. Results indicate that the Upper Mississippi River basin has an increasing trend in streamflow quantity. For the Pacific Northwest and some stations in Florida, the streamflow quantity is decreasing.
DE: 1807 Climate impacts
DE: 1860 Streamflow
SC: Hydrology [H]
MN: Fall Meeting 2005