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Environmental Systems

Regular course within the MSc Environmental Geography and M.Sc. Human Geography at Marburg University.

Course Description

The natural and man-made environment we live in is complex. This complexity is the result of both countless entities and countless interactions between these entities that together form the environment and its dynamics. As a result, we cannot express or explain the world as a whole. But even (very small) sub-components of this environment still bear a complexity well beyond our cognitive abilities. One approach to deal with this dilemma is to build descriptive models for well-defined sub-sets of the environment and equally well-defined research questions. In this module we will learn how to descriptively model some aspects of real-world systems and how to perform simulations.

The individual sessions can be grouped into three sections:

  • First contact: in sessions 1 to 4 we will derive some basic definitions and concepts and start training your modeling competence using different types of graphical modeling tools. Based on that, you will perform first simulations of simple models using a piece of paper and a pencil, a spreadsheet program like Excel or OpenOffice Calc and finally an industrial standard simulation software called Vensim. At the end of this section you should be able to handle some basic terminology and know principal modeling rules. In addition, you should be able to sketch the dynamics of simple models and perform simulations of them by using a modeling software.
  • Training: in sessions 5 to 9 we will model three dynamic systems starting with the mother of all dynamics models, the predator-prey model and ending with the often cited tragedy of the commons theme. At the end of this section you should have trained your modeling competence to a point where you feel confident to develop models of similar complexity.
  • Application: in sessions 10 to 13 we will slightly change the perspective and focus on simulation not on the modeling itself. As a basis, we will provide more complex models (CO2 dynamics as well as crop farming for the physical geography course and knowledge management as well as globalization and competition for the human geography course) which you will use for sensitivity studies. At the end of this section you should be able to interpret model behavior and simulation results in an applied scientific context.

Have fun!


The course has 1 session per week, 3 hours per session.

Session Topic Content
1 Systems, models, simulations Models
Systems and boundaries
2 Graphical modeling Word model
Causal loop diagram
Stock & flow diagram
3 Integration Graphical integration
Spreadsheet simulation
4 Computer-based modeling Intro to Vensim
5 In-depth example 1 Predator-prey model
(the all-time classic)
6 In-depth example 2 Forest growth model
Generic structures
7 Tragedy of the commons 1 Common resource exploration
8 Tragedy of the commons 2 Sustainable resource use
9 Decision support Fish pond system
10 CO2 dynamics 1/2 Components of the CO2 balance
Analysis of a CO2 balance model
11 CO2 dynamics 2/2
12 Crop farming 1/2 Components of the farming system
Analysis of a farming model
13 Crop farming 2/2 Sensitivity studies
Model behavior
Model interpretation
14 Wrap up


This course has been inspired by and partly adapted from the excellent Road Maps course from the system dynamics group of J. W. Forrester, Sloan School of Management, Massachusetts Institute of Technology [Forrester1998]. This is especially the case for some working sheet structures and reading suggestions of the introductory sessions.

Most of the models and parametrization are taken from another yet equally excellent book series called System Zoo and has been written by H. Bossel [Bossel2004a], [Bossel2004b] and [Bossel2004c].

courses/msc/environmental-systems/description.txt · Last modified: 2016/10/13 11:45 (external edit)