Welcome to the provisional home page of the WATER 1 simulation model!

This model regards strategies for water supply companies to deal with nitrate pollution of groundwater aquifers. In Germany, as well as in many other European regions, nitrate pollution is one of the most important problems for water protection and water supply. The simulation of an existing water supply company shows a high level of conformance between simulation results and economic data of the company. The simulation of scenarios with high nitrate pollution shows important differences between the strategies of using deeper aquifers, of technical treatment of raw water, and of co-operation with the agriculture regarding costs and environmental sustainability. Also these results reflect fairly well the situation in Germany.

The model was implemented using the Java based VSEit framework. For latest information about VSEit, please visit www.vse.de.

Name of Model: WATER 1
Author: Yvonne Haffner
Date: 07/03/01
VSEit Version: 0.97
Start Simulation: Netscape Navigator 4.x (on Windows 95/98/ME/NT4/2000, Linux, and Solaris)
Microsoft Explorer 5.x (on Windows 95/98/ME/NT4/2000)
Other browsers and platforms (e.g. Netscape Navigator 6 on Windows 95/98/ME/NT4/2000 and Linux)

By clicking at the appropriate link above the should simulation will automatically be downloaded and executed as an applet in your browser. If not already installed, your browser attempts to download and install a plug-in for the required Java version, too. If you encounter problems with the automatic installation performed by your browser, download the Java Runtime Environment (JRE) for Java 2, version 1.3.1, from http://java.sun.com/j2se/1.3/jre/index.html. Then close your browser, install the JRE, and try again.

If the applet starts up, choose File > New Simulation...from the main menu and provide any name for the new simulation run, you are going to create. Then, issue command Simulation > Run and watch the show.

Model Structure and Behavior

Two main aspects of a water supply company are modeled: First, the water withdrawal and water delivery to the housholds. Second, decisions about investment, reinvestment, and loan taking. For water withdrawal there is the class water ressource with specific phyiscal attributes and methods. Different kinds of plants are needed for withdrawal, treatment, storage, and distribution. Class CustomerType determines the water demand. To keep the plants working the company has to reinvest and, therefore, the company has to take out loans. The bank grants loans with specific credit terms. The company has to do investments if a measure against the nitrate pollution has to carry out. Because the strategy 'Co-operative agreements with agriculture' is a specific measure cooperation is a single class.

For a detailed description of the model and its use, see Yvonne Haffner, Stefan Gramel (2001) Modelling Strategies for Water Supply Companies to Deal with Nitrate Pollution. Journal or Artificial Societies and Social Simulation Vol. 4, no. 3, http://www.soc.surrey.ac.uk/JASSS/4/3/11.html.