Applications of Climatology and Meteorology to Hydrologic Simulation
R. A. Clark, G. E. O
The normal, log-normal, square-root-normal, and cube-root-normal frequency distributions of hydrometeorological data, viz., precipitation, evaporation, and streamflow, were studied for selected regions of Texas. The regions were: East Texas, South Central Texas, and the Low Rolling Plains. These frequency distributions can be used to generate synthetic sequences of hydrometeorological data by simulation techniques of operations research. Results of this research show precipitation data in all regions conform to the square-root-normal distribution; streamflow data conform to the log-normal distribution; and evaporation data conform to all of the frequency distributions tested. Additionally, the streamflow and precipitation data were fitted to the Gumbel extreme-value and to the log-Pearson type III distributions. When monthly series of the data were used, both streamflow and precipitation data fit the log-Pearson type III distribution more adequately than the Gumbel distribution. Monthly series of evaporation data were fitted to the Gumbel distribution only and conform very well.