1. General Model Information

Name: SAFE: dynamic soil acidification model

Acronym: SAFE

Main medium: terrestrial
Main subject: biogeochemistry
Organization level: ecosystem
Type of model: not specified
Main application:
Keywords: soil chemistry, acidification, dynamic, multi-layer, weathering rate, soil layers, Profile, MakeDEP


Biogeochemistry group,
Department of Chemical Engineering II,
Lund University,
P.O. Box 124,
S-221 00 Lund,

Homepage:Department of Chemical Engineering II

Fax: Int+ 46 46 222 82 74

email: mattias.Alveteg@chemeng.lth.se



The SAFE model is a dynamic multi-layer soil chemistry model that calculates the weathering rate and the soil chemistry in the soil layers.
The SAFE model needs physical and chemical input regarding the soil profile as well as time series of deposition, uptake and precipitation. The input are organised into different files, some of which contain constant input and some time-series of input. SAFE may be run on different computers with different operating systems and is currently compiled to run on a Mac or under DOS. Since DOS only allows a maximum eight character name and a three character extension the filenames are slighlty different when running under DOS.

The SAFE model assumes that the soil initially is at steady-state. It is therefore important to start the SAFE simulation before there was any major influence from industrialisation. We recommend that you start your simulation sometime between 1700 and 1800 depending on the location of your site.

Since SAFE assumes steady-state initially, it needs initial values of base cation (Ca 2+ , Mg 2+ and K + ) concentration, pH and base saturation. Initial values of base cation concentrations and pH in the different layers are calculated by the initSAFE program.
The initSAFE program is, like PROFILE, a steady-state version of the SAFE model. It takes the site.init file and the time-series files, calculates the historical steady-state and prints the output to a file "site" which in turn is the input file to the SAFE model. The initSAFE program also produces a file "site.rain" that contains pH and ANC (acid neutralising capacity) for the rainwater, or rather the wet and dry deposition. The "site.rain" file can be used to check whether your historical deposition data is reasonable.

Historical base saturations is usually not available and you may therefore enter measurements of present base saturation for different layers (and different years if available) in the "site.cal" file. The SAFE model will then calibrate the historic base saturation until a reasonable fit with measurements are achieved. Cation exchange is modelled with a gapon isoterm and the gapon exchange coefficient is assumed to be constant over time.

The MakeDEP Program reconstructs deposition and uptake from present day values and its output may be used by SAFE as input.(see BioGeoChemistry Group Models homepage)

Source of abstract: BioGeoChemistry Group; SAFE download page: Running the SAFE model, a short and sketchy guide (.pdf-file).

II. Technical Information

II.1 Executables:

Operating System(s):

II.2 Source-code:

Programming Language(s):
free download files

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

III.2.2 Output

IV. References

Source: Research at the Biogeochemistry group





V. Further information in the World-Wide-Web

VI. Additional remarks

Last review of this document by: Juergen Bierwirth Fri Dec 18 15:03:20 MET 1998
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:49 CEST 2002
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