9421030 Dracup The three primary objectives of this research are as follows: 1) To develop a long range tool, one that will predict streamflow and drought six to twelve months in advance. 2) To investigate the connection between climatic variations and regional hydrologic processes and, in support of this, to identify regions that respond specifically to ENSO events. 3) To assemble, with the assistance of international collaborators, a Pacific Rim streamflow and drought indice data set. The research plan and methods can be summarized as follows: 1) With the cooperation of several Pacific Rim researchers, to compile a streamflow and drought indice data set that is the basis of this research effort and which will be made available to the public. 2) To use the statistical methods of harmonic analysis and spatial cross correlation analysis in identifying regions of coherent response to ENSO. 3) To quantify the ENSO impact by evaluating the shift in the probability distributions of of La Nina, Non-Enso, and El Nino events. Boxplots will represent the 10th, 30th, 50th, 70th, and 90th percentile values of each distribution. 4) To develop streamflow and drought prediction models based on fuzzy concepts, one model to be based on fuzzy rules, the other on fuzzy regression. The fuzzy ruled- based model can be viewed as the prediction of a hydrologic variable condition upon atmospheric circulation patterns. 5) To apply the prediction models to the western U.S. The time period of 1948-1988 will be used for calibration and verification of the models, and these models will then be applied to the other relevant regions of the Pacific Rim. Modifications will be made to reflect the regional atmospheric conditions. The significance of this research will be its major contribution to long range prediction of streamflow and drought. Current streamf low forecasting techniques rely on known precipitation quantities and are limited to forecasts of three to six months in advance. This proposed research relies on large scale circulation patterns that occur six to eight months in advance of a streamflow or drought. Their use may make possible predictions that could be given as much as a year in advance. Secondly, a unique data base that will support future research, far beyond that included within this proposal, will be assembled and available. Finally, the work of international collaboration will not only forge new international research links, as large data gaps are being filled in, but the possibility remains of conducting further research using this group of international collaborators as a base.
