For the six regions taken under investigation a statistical analysis of mean monthly flows was attempted. The relationship was established for all but one region.

The analysis compared the coefficient of variation of the monthly flows to the size of the drainage area for each basin in a region. The regions were defined by basins of similar topography and climate. Streamflow prediction would be made by mathematical synthesis from the standard deviation parameter computed from the graphical relationships established for each region.

The value of such a relationship was evidenced by the general consistency of the results.