Input data

The following data must be available for all elements or nodes in the model file:

Terrain elevation (attribute GELA): For calculating the relief energy or the slope.

Water level depth (attribute FLUR): For determining evaporation and direct runoff. The depth to the groundwater table can be calculated in SPRING as the difference between GELA and EICH (Attributes Compute Calculator... GELA - EICH).

Precipitation (attribute NIED ).

Soil type (attribute NMBT): The soil type must be specified in the model file according to the following classification (nFK = usable field capacity:

Soil type	Classification (= NMBT)
Sand, nFK low	1
loamy sand, nFK medium	2
Loamy clay, nFK high	3
Loess soils	4
Pseudo gley	5

Land use (attribute NMFN ): The land use must be specified in the model file according to the following classification:

Land utilisation	Classification (= NMFN)
Agricultural use	11
Farmland	12
Grassland	13
Fallow land	14
Without vegetation	15
Decidous forest	21
Mixed forest	31
Coniferous forest	41
Mixed vegetation, sealing ratio 0%	51
Mixed vegetation, sealing ratio 1-20%	52
Mixed vegetation, sealing ratio 21-40%	53
Mixed vegetation, sealing ratio 41-60%	54
Mixed vegetation, sealing ratio 61-80%	55
Mixed vegetation, sealing ratio 81-100%	56
Water areas with drainages	61
Water areas without drainages	62
Dumps, landfill undifferentiated	71
Landfill in operation (unvegetated), nFK low	72
Recultivated landfill (mixed vegetation), nFK low	73
Heap in fill (unvegetated), nFK low	74
Recultivated waste rock pile (mixed vegetation) nFK low	75
Mud pond without vegetation, high nFK	76
Roof areas drained	81
Asphalt, concrete drained	82
Concrete composite (new), drained	83
Mosaic-/small paving, drained	84
Grass pavers, drained	85
Compressed, drained	86
Sealed, not drained	91
Asphalt, concrete not drained	92
Concrete composite (new), undrained	93
Mosaic-/small paving, non-drained	94

Standardised land use codes such as RVR code (KVNR attribute), CORINE land use data (NCLC attribute) or ATKIS data (NATK attribute) can be used to determine the NMFN data type. Depending on the format, the data can be imported as a structure and assigned in SPRING.

Slope class (attribute NMGK): The maximum slope between the nodes (possibly also via the diagonal) of the element is used as the decisive slope in the finite element concerned, which the programme calculates automatically from the ground level at the individual nodes. The slope class must be specified in the model file according to the following classification:

Slope class (NMGK)	Relief energy [m/km²] or slope [%]
1	0 - 20 or 0 - 2
2	21 - 40 or 2 - 4
3	41 – 100 or 4 -10
4	> 100 or > 10

Via the menu item Attributes Compute Groundwater recharge By Messer 2008 Determine classes of incline of ground, the gradient class can be determined automatically in SPRING.

Watertable depth class (attribute NMFK): The groundwater table depth class is determined on the basis of the depth to the groundwater table and must be specified in the model file according to the following classification:

Watertable depth class [m]	Classification (= NMFK)
Water table depth 0 -1.0	1
Water table depth 1.0 – 2.0	2
Water table depth 2.0 - 3.0	3
Water table depth > 3.0	4

Use the menu item Attributes Compute Groundwater recharge By Messer 2008 Determine classes of depth to groundwater table the depth to the groundwater table classes can be determined automatically in SPRING.

Climate zones (attribute NMKL): The climate zones can be specified in the model file according to the following classification

Climatic zone, based on potential evapotranspiration (ETpot)	Classification (= NMKL)
ETpot 400 – 480 mm/a	1
ETpot 480 – 500 mm/a	2
ETpot 500 – 520 mm/a	3
ETpot 520 – 540 mm/a	4
ETpot 540 – 580 mm/a	5
ETpot 580 – 640 mm/a	6

They can also be determined automatically in SPRING by specifying the potential evaporation (attribute NETP input in [m/a]) via the menu item Attributes Compute Groundwater recharge By Messer 2008 Identify climatope from ETpot.

Determination of the total evaporation