Drought in Southwest Georgia and the Use of Ensemble Streamflow Prediction

Abstract

Proceedings of the 2001 Georgia Water Resources Conference, April 26 and 27, 2001, Athens, Georgia.Ensemble Streamflow Prediction (ESP) was used to produce medium to long-range streamflow forecasts at two sites within the upper part of the Flint River Basin in Georgia. Forecasts using ESP for mean monthly streamflows from July through September 2000 were produced. These were compared to actual streamflows by using provisional data from the U.S. Geological Survey (USGS). ESP has been used mainly assuming that each year of meteorological data is equally likely to occur in the future. This means that equal yearly weights are assigned. In this paper, an alternative is presented, that of deriving variable yearly weights based on precipitation outlooks. 'Precipitation outlooks issued by the National Oceanic and Atmospheric Administration (NOAA) through the Climate Prediction Center (CPC) were used in this study. Curves showing probability of exceedance were derived for equal and variable weights. It is thought that variable weights should be adopted; however, further investigation on their derivation is suggested. An evaluation of the range of influence of initial conditions should also be considered so that a meaningful forecast window can be determined.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, Natural Resources Conservation Service, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1990 (P.L. 101-397) or the other conference sponsors