Integration of Raster-based GIS and system dynamics and its application
Pitan Singhasaneh, Dr. Apisit Eiumnoh, Dr. John E. Lukens,
Dr. Harvey Demaine
Asian Institute of Technology
Bangkok, Thailand
Abstract
Some of the existing systems can be analyzed not only from its dynamical aspect or geographical aspect, but simultaneously from both. Integration of Geographic information system and system Dynamics provide us a more thoroughly understanding of the behavior of these systems. Apple computer and SuperCard software were chosen as tools for the development of this integrated program, using Collected data of pattaya city of Thailand, a model was developed for the simulation of a land use change.
Introduction
At the present, Geographical Information Systems (GIS) and system Dynamics can still be considered as a scientific tools in the developing stage. They are gaining popularity because of the usefulness in their own fields. At one end, GIS deals with the data, their position in coordinate system, their attributes, and their spatial interrelation with each other, while system Dynamics tries to understand problems which are dynamic (involve quatities which change over time) , and also, involve the notion of feedback.
GIS packages and system dynamics packages have their own strengths and weaknesses. They are summarized in the following table :
| |
GIS | System dynamics |
| GIS capability |
| -position with respect to a known coordinate system |
Yes. | Yes, can be done using 'array' in Dynamo III, with severe limitation |
| -attributes of each point in the coordinate system |
Yes. | Yes. |
| - spatial interrelations with each other Producting |
Yes. | Yes.In a certain way. |
| -Producing 'Thematic' map |
Yes | No. |
| Modelling capability |
| -repetitive calculation | No
(Canbe done manually) | Yes. |
| -dynamic | No.
(can be done manually) | Yes. |
| -feedback | No. | Yes. |
-producing graphs of
any variable over
time |
No | No |
In other words, GIS is not made for analyzing systems whose value of factors over time (repetitive computation needed), and system Dynamics is not made for dealing with spatial relationship. This, of course, creates a gap between the two methods, which limits the study and in in-depth understanding of any systems falling inside this
