Rainfall Pre-processing - Overview

This module transforms the daily rainfall data stored in the Oracle database into a database structure readable by the runoff model. Data can be either online or offline; offline execution is much faster.

Processing is by hydrological year. Selection of the years is by pull-down menu. Take care, that the first year is always smaller or equal the second year and the second year is always larger or equal the first year, otherwise one of the following warnings will show up:

respectively

.

The following steps are performed for each year if you press the "execute key" :


  1. For the year under processing, stations with sufficient data (exceeding thresholds for minimum number of readings and minimum total annual rainfall) are selected.
  2. For the selected stations and the year under processing, ordinary readings (data code "-") and estimated values (data code "e") are transferred to the destination table.
  3. For the selected stations and the year under processing, intervals of accumulated readings (data code "a") are traced, filled day by day randomly to fulfill the accumulated total and finally transferred to the destination table.
  4. For the selected stations and the year under processing, remaining days are filled with zero values in the destination table.
  5. For the selected stations and the year under processing, data gaps are traced (data code "c" for begin and "d" for end of gap) and the corresponding records deleted from the destination table.
  6. Totalizer stations (stations with a single reading at the end of the season) are filled with values calculated by means of a special algorithm.
All procedures are also visualized by a set of flowcharts.

Particularly if connected to ORACLE, processing may take some time. The initial preparation for totalizer and virtual stations needs to be executed, before the individual years can be processed. A status bar on the form is indicating the progress.

End of processing is indicated as well.



Note: the export of rainfall data or station data to dBase files is not  required any more, as the core rainfall/runoff model is now directly accessing the same linked tables of the Access database