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Technical Report

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hydrology, streamflow, water supply, runoff, flow frequency analysis, pollution abatement, Pearson type III distribution, *low rate extremes, minimum flow, maximum flow, mean flow, discharge rates, flood flow


Stream discharge data for the State of Arkansas is analyzed for representative statistical parameters. The statistical distribution most applicable to stream discharge data in Arkansas is the Pearson type III skew frequency curve. The parameters of the Pearson type III curve for all available records in Arkansas are included as Appendix A. The parameters of the logarithmically normal frequency distribution are included as Appendix B for mean daily discharge, minimum daily discharge and instantaneous minimum daily discharge. The logarithmically normal frequency distribution may be used for the lower discharge rates in lieu of the Pearson type III distribution except where instances of zero discharge are likely. The following determinations are applicable to the State of Arkansas. There is no correlation between the coefficient of variation and area for minimum daily discharge. There is no correlation between skewness and area. The mean daily discharge rate is one cubic foot per second per square mile. Suggested applications of the parameters in Appendix A are set forth for flood control, pollution control and water supply.

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