1. General Model Information

Name: Agro-Ecosystem Management and Optimization

Acronym: ECOTOPE


Main medium: terrestrial
Main subject: agriculture, population dynamics,
Organization level: Ecosystem, Population
Type of model: ordinary differential equations, difference equations (1D),
Main application: simulation/optimisation tool, research,
Keywords: agroecosystem modelling, optimum control theory, assessment, management optimisation, dynamic programming

Contact:

Ralf Seppelt
Institute of Geography and Geoecology
Langer Kamp 19c
D-38106 Braunschweig
Germany
Phone: +49 (0) 531 391 5608
Fax: +49 (0) 531 391 8170
email: R.Seppelt@tu-bs.de
Homepage: http://www.tu-bs.de/institute/igg/ag-aus/pers/ralf/index_en.html

Author(s):

R. Seppelt

Abstract:

ECOTOPE, ROTATION and PESTICIDE are model applications in the framework of optimum control theory.

A typical example of a simulation model, which describes processes of an agricultural--ecosystem, is used to derive optimum management strategies: fertilising schemes, pesticide application and crop rotations. The simulation model for crop growth, nitrogen dynamics in soil and a pest population is based on data series from the collaborative research project 179 ''water- and matter-dynamics in agro-ecosystems'. The model is applied to the environmental conditions of one investigation site of the project: the 'Ohebach' catchment in Lower Saxonia ('Niedersachsen'), Germany.

An application to optimum control theory requires appropriate numerical procedures. Dynamic programming algorithms are used based on general dynamic systems. Numerical effort is decreased by making use of properties of environmental models. This is achieved by a hierarchical approach to the optimization problem. Generic code was developed that is applicable to a general dynamic system.


II. Technical Information

II.1 Executables:

Operating System(s): Windows 9x/NT, UNIX
http://www.tu-bs.de/institute/igg/ag-aus/pers/ralf/download/examples.zip

II.2 Source-code:

Programming Language(s): GNU-C, Fortran
http://www.tu-bs.de/institute/igg/ag-aus/pers/ralf/download/libdp.zip

II.3 Manuals:

LibDP - Library for Optimum Control of Heterogeneous Dynamic Systems by Hierarchical Dynamic Programming (hDP)

http://www.tu-bs.de/institute/igg/ag-aus/pers/ralf/download/manual.pdf

II.4 Data:

Important part of the model is the LibDP - Library for Optimum Control of Heterogeneous Dynamic Systems by Hierarchical Dynamic Programming (hDP)



III. Mathematical Information


III.1 Mathematics


III.2 Quantities


III.2.1 Input

III.2.2 Output


IV. References

R.E. Bellman (1957) Dynamic Programming. Princeton University Press, Princeton

R.E. Larson und J.L. Casti (1978): Principles of Dynamic Programming, Marcel Dekker, Inc., New York, Vol 1 & 2

R.E. Bellman and S.E. Dreyfus (1962): Applied Dynamic Programming, Princeton University Press, Princeton

R. Seppelt (1999): Applications of optimum control theory to agroecological modelling. In: Ecological Modelling. 121(2-3): 161-183.

R. Seppelt (2000): Regionalised optimum control problems for agroecosystem management. In: Ecological Modelling. 131(2-3), 121-132

R. Seppelt (2001): Hierarchical Dynamic Programming and Applications in Ecosystem Management. In: Environmental Modelling and Software. 16(3):377-386

R. Seppelt(2001): Agroecosystem Management. In: J. Pinter (edt.): Global Optimization ^ Selected Case Studies, Kluver, Dordrecht, New York, to appear 2001.



V. Further information in the World-Wide-Web


VI. Additional remarks


Last review of this document by: Fri Apr 20 16:43:45 2001
Status of the document: Contributed by R.Seppelt@tu-bs.de
last modified by Tobias Gabele Wed Aug 21 21:44:42 CEST 2002

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