Look-up Tables are an important feature of a good data base design. Typically they are small tables, which contain parameter codes and general values.
Altogether, the Pre-processing module uses the following Look-up Tables (sorted alphabetically). They are always linked, either online or offline. Therefore, their names are included in the Table-links.
|LU_USE_TYPE||For monthly production|
|WATER_USE_BILL_CAT||For water billed by WAJ|
The following LUTs are NOT linked, however their contents help to understand the codes used in various database tables:
|END_USES||of treated wastewater|
|ISIC_CLASS_CODES||classification of industrial facilities|
Different from the Irrigation module the following references are not contained in look-up tables but are defined in the VBA code:
For example, the LUT for salinities looks as follows:
Table Salinity_Class TDS (total dissolved solids) in mg/l
|1||Salinity Class 1||0||1000||Good for Drinking & generally no restriction in irrgtn|
|2||Salinity Class 2||1000||2000||Slight to moderate restriction on irrgtn use|
|3||Salinity Class 3||2000||2800||Severe restriction on irrgtn use, only for special crops|
|4||Salinity Class 4||2800||50000||Usable only after desalination|
|0||no Leaching||0||0||No consideration of salinity|
In the corresponding tables (particularly the STP tables), only the entry of the salinity class field [S_CLASS] is used. If salinity classes are to be redefined, it would be sufficient just to modify the Look-up table.