The transient input file has the following structure:

A starting time is defined after the general data (comment, time units). All subsequent data refers to this step in time until a new reference time is specified. As with the input files, each data block is terminated by a blank row. The input format for the values is 5(I6, F10.2). All time steps must be entered in ascending order. Three blank rows make up the end of the file.

Lines 1-3: Rows for optional comments or project description. The first two lines of this optional comment are used as headings for the hydrograph plots. Any text is possible.

Line 4: Blank row

Line 5: Time unit for mass transport: The corresponding text must be entered left-aligned from the 18th column after the data identifier 'ZEITEINHEIT MENG ' (Time unit quantity). The available time units are SEKUNDE (seconds), STUNDE (hour), TAG (days), MONAT (months) and JAHR (years). All mass transport data of the data types KNOT (sources and sinks) and FLAE (area seepage) must use this specific time unit.

Line 6: Time unit for the time steps: The time unit in which the time steps are specified is defined here. There are two options:

• Definition of a time unit: After the data identifier 'ZEITEINHEIT ZEIT' (Time unit time), one of the time units SEKUNDE (seconds), MINUTE, STUNDE (hours), TAG (days), MONAT (months) or JAHR (years) is specified from the 18th column onwards. The time steps are defined using the ZEIT (Time) data type and a real number (F10.2)..

• Definition of a reference date: After the data identifier 'BEZUGSDATUM ' (The reference date), a date in the form 'DD.MM.YYYY' (day, month, year, including the full stops) is specified from the 13th column onwards. The initial state refers to this date. Each time step is defined using the DATUM (Date) data type and a specific date. Internally, calculations are made in the day-time unit, whereby the conversion is made according to the calendar (including leap years).

Line 7: blank row

Lines 8+9: Specifying time steps: Depending on the entry in line 6, there are two options for defining the time steps:

When specifying with ZEITEINHEIT (Time unit), the time steps are also entered with the ZEIT (Time) data type. In the following line, a real number (F10.2) is entered for the selected time unit

Example

ZEIT (Time)

2.5

If a ZEITEINHEIT SEKUNDE (Time unit seconds) is selected, the specification "2.5" refers to the time 2.5 seconds after the initial state.

When using a BEZUGSDATUM (the reference date), the time is entered using the DATUM (Date) data type. The specific date for the time step is entered in the following row.

Example:

DATUM

02.04.1995

Line 10: blank row

Line 11: Data type with associated values:

Lines 12ff: After the data identification line (line 11), the values are entered in the standardised format 5(I6, F10.2), i.e. up to five pairs of values (node or element number and associated value) can be entered in one row (spaces are permitted but no blank rows). An entry in the form “from ... to ...” as with the model file's read-in algorithm is not possible.

Each data type is concluded with a blank row.

Further data types can be specified in any order at the same time step (each separated by a blank row), or the next time step starts with the structure repeated as from Line 8. Time steps can also be defined without datasets.

Note: If node numbers have more than six digits, the format writer for the node numbers can be changed to 7 digits in the 7th line of the file using the NUM 7 entry. The values can then be specified in a line with the format 5(I7, F10.2).

Creating the transient input file from transient structures