1. General Model Information

Name: BYM 1.4

Acronym: BYM

Main medium: terrestrial
Main subject: meteorology, agriculture
Organization level: cosystem, landscape
Type of model: ordinary differential equations
Main application:
Keywords: crop, soil, water balance, evapotranspiration


Ms. N.B. Brisson.
INRA, Station de Bioclimatologie, Domain St. Paul, Site agroparc, F-84914 Avignon Cedex 9, FRANCE.
Phone: +33.90.316118
Fax: +33.90.899810
email: brisson@avignon.inra.fr



Agrometeorological soil water balance for crop simulation models. The use of crop simulation models on a large scale for agrometeorological purposes is often limited by their inputs being non routinely collected data, especially with regard to their soil water balance compartment. The objective was to develop a water balance submodel which can be run with readily available inputs. The model predicts water use, soil evaporation, crop transpiration throughout the growing season. Physiological reduction factors, as influenced by water stress, are derived from the soil water availability. This was achieved by using empirical relationships such as the reservoir analogy to assess water availability in relation to root development. The framework of using conditions is assessed by sensitivity analyses performed on inputs: the model can be run with an incrementing time step of ten days and soil information given by soil maps, i.e. soil texture and depth, which fits to agrometeorological purposes. Moreover, the model is shown to realistically describe soil water depletion, crop evapotranspiration and rooting depth. Yet incorporating effective rainfall simulation, i.e. both runoff and rainfall interception by the canopy, would advantageously improve the model.

Purpose of the model:

Model parentage: -

Source of the AbstractCAMASE Register of Agro-ecosystems Models

II. Technical Information

II.1 Executables:

Operating System(s): IBM compatible PC AT. Contract necessary: Costs: : No. Comments:

II.2 Source-code:

Programming Language(s): Microsoft FORTRAN-77.

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

Rate variables: Evaporation, transpiration.

State variables: Soil water content, rooting depth.

III.2.1 Input

Weather data (temperature, global radiation, potential evapotranspiration, rainfall), crop driving variables (irrigation amount, leaf area index), soil properties (initial soil moisture, soil depth, texture). Input check in model: -

III.2.2 Output

Stress factors.
Basic spatial unit: -
Time interval of simulation: 1 Day or 10 days.

IV. References

Brisson, N., 1992. Agricultural and Forest Meteorology 59: 267-287

V. Further information in the World-Wide-Web

VI. Additional remarks

Parentage: -
Last review of this document by: T. Gabele: Dec 19 1997
Status of the document:
last modified by Joachim Benz Mon Jul 2 18:31:37 CEST 2007

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