UM-45 : Disaggregation techniques user's manual

Abstract

The user's manual described here, provides the details of a main computer programme specifically written for establishing a suitable statistical relationship between the station values within /outside the basin and average basin value of monthly precipitation. In the programme, three different approaches namely (a) frequency analysis method, (b) correlation concept, and (c ) disaggregation approach, have been described considering different, possible alternatives which include combinations of (i ) excluding zeros and including zeros in the data for the purpose of analysis, (ii ) power transformation and (iii ) considering distributions such as EV1 and PT3 distributions. Thus in all 16 possible alternatives based upon these three approaches have been considered in this package.

The package consists of one main computer programme and seventeen subroutines all written in Fortran language. Programme ones run asks to choose any one out of 16 methods, or 8 methods or all the 16 methods together. Later two options provide statistics of results of all the selected methods in the form of a table along with error details. Historical monthly values of precipitation at all the stations within /outside the basin along with weight of each station are supplied in the input file. Values to be disaggregated are to be supplied in another file.

Package developed can be used with ease as Input data requirement is minimum.