Model Appendix B Contents: Boundary Conditions

An ASCII file suitable for use by the Boundary Condition options (Aquifem-n module) must consist of a descriptive header as well as the actual data contained in the rest of the file. The header of the file specifies the number of columns in the file as well as the name, type, number of decimal places (if floating point) and width of every column in the file. This descriptive column information must be present else the file cannot be loaded. An example is given below.

Example - Boundary Conditions load file

*
* VARIABLES 3
* 
* TIME                       F 10 0     
* DATE                       C 14 
* VALUE                      F 10 2    
* 
         1     01-Jan-82     08.40  
         2     30-Mar-82     11.96  
         3     01-Apr-82     11.90  
         4     04-Apr-82     11.87  
         5     06-Apr-82     11.80  
         6     07-Apr-82     12.80  
         7     08-Apr-82     12.80  
         8     10-Apr-82     12.70  
         9     13-Apr-82     12.71  
        10     14-Apr-82     12.60  
        11     15-Apr-82     12.70  
        12     16-Apr-82     10.60  
        13     20-Apr-82     10.60  
        14     21-Apr-82     12.52  
        15     22-Apr-82     12.50  
        16     23-Apr-82     12.50  
        17     24-Apr-82     12.49  
        18     27-Apr-82     12.40  
        19     28-Apr-82     10.30  
        20     29-Apr-82     12.30  
        21     30-Apr-82     12.30  
        22     03-May-82     12.30  
        23     05-May-82     12.30  
        24     06-May-82     12.30  
        25     07-May-82     12.30  
        26     10-May-82     12.20  
        27     11-May-82     10.20  
        28     12-May-82     12.20  
        29     13-May-82     12.20  
        30     14-May-82     10.20  

The number of variable/column description lines to follow is indicated by the number following the word VARIABLES. Each column is then described by its name, type (C - Character, F - Floating point, I - Integer), width (eg. 20) and number of decimals (eg. 10). The number of decimals is ignored for integer type variables.

The Load Times options in the Boundary Conditions box will always load values from the TIME column. Similarly, the Load Values options in the Boundary Conditions menu will always load values from the VALUE column. Any other columns present in the file will be ignored. For example, the DATE column in the example given here is not used. The TIME and VALUE columns should always be specified as Floating Point (i.e. type 'F') columns. The Boundary Conditions load file may have any name.

The multiplier specified when loading values enables a constant multiplier to be applied to all the values loaded from the file (a value of two for the multiplier would double every value). This enables such factors as constant changes in rainfall over time to be easily incorporated when specifying boundary conditions.