These parameters are required as the basis data for constructing a groundwater flow model:

Main water bodies: Water levels in metres (usually meters above reference datum) for at least two points: Fixed potential edge POTE

Tributaries: Water level in the upper course (m), possibly discharge measurements for leakage determination VORF and LERA

Abstraction wells: Withdrawal rates KNOT (negative sign, convert to m³/time unit of the model file)

Groundwater recharge: Precipitation, soil type, land use, slope for calculation of recharge GW-N (mm/time unit of the model file)

Geology: Hydraulic conductivity values in m/s KWER

Surface elevation: GELA, and possibly data on an impermeable layer in the subsoil UNTE, otherwise calculation with one thickness: MAEC

Groundwater level measurements: Groundwater/piezometric surface EICH

 

Note: The time unit of the model file is defined when a new project is created (File New).

 

The best sources for such information tends to be country-specific geo-information websites or portals. Additionally, the following sources can provide the abovementioned data:

• Digital elevation models and tiff files: Satellite data (ASTER, SRTM)

• Groundwater measuring data, water level in rivers: Monitoring programs, State Environmental Agency, water boards, waterworks, etc.

• Withdrawals: Well operators

• Geology: Geological maps, exploratory drillings, pumping tests

• Leakage: e.g. calculation via K-values of the environment and discharge measurements

• Groundwater recharge: e.g. on the basis of RVR data, according to Schroeder and Wyrwich or Meßer

 

Defining the model limits