UM-2 : Frequency analysis

Abstract

The user's manual gives the details of a computer programme for best fit distribution using normalization procedures and chi-square criterion. Various normalization procedures which have been used in the programme are a. Inverse Pearson type III transformation, 2. Log normal transformation based on theoretical relationships, 3. Log transformation, 4. Inverse log Pearson type Ill trans-formation and 5. Square root transformation. The best fit normalization procedure corresponding to each season is chosen based on chi-square statistic. The programme is capable of comparing any combination of above mentioned normalization procedures. The same programme can be used for any type of seasonal hydrologic data i.e. daily, pentad, weekly, ten daily, monthly or annual. The data should be continuous and observations across the years should be independent.

The computer programme is written in Fortran IV. The definitions of the terminology related to normalization procedures and the chi-square statistic have been given in the manual. The input data specifications and output description are explained. The user's manual also contains the test data and example calculations