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Digital Image Processing
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Integration of Raster-based GIS and system dynamics and its application
Objectives of the study
The immediate objective of this project is to demonstrate the importance of the integration of system Dynamics (SD) and Geographic Information System (GIS) . To do this, a "SuperCard" program will be written with the capacity of dynamically simulating a particular model through 'STELLA' and displaying outputs in GIS'S raster format.
The program is also hoped to be useful in; (1) gaining insights and understanding of a relationship between SD and GIS, (2) analyzing a real world problem, for example , model-based policy analyses, which involve the use of the model to help investigate why particular policies have the effects they do and to identify policies that can be implemented to improve the problematic behavior of the real system, and (3) assisting in better and improved decision making in land and other natural resource management in other areas, which furthermore, promotes economic growth and better living conditions of the people.
The developed program
- Technical Data
| Hardwares: |
Macintosh IIci, 4 MB RAM, 80 MB HD |
| Softwares: |
STEELLA for business, STEELLAStack, Super Card. |
| Data Structure: |
Raster -based GIS |
- Design capability of the Program
The program will be designed to, have the following capabilities:
- Store input data and display GIS maps on computer screen,
- GIS's overlaying capability
- Simulate System Dynamics models through STELLA, and display the output in the form of GIS map,
- Real Number Handling Ability. Not like some GIS systems, it will be able to store information of each cell in a form of real numbers. This is very useful in some cases where it is essential to use real numbers in the calculation.
- The program is also intended to be interactive, which means that, during the running of the program, the user will be able to change the value of variable (s) or put in/take out
constraints from the model. This will be very useful in learning and understanding the dynamics of the model and the impact of each variable having on the model in greater details.
- General Structure of the Program
* Arrows represented communication links.
Program written in SuperTalk
The general structure of the program is illustrated above. GIS part and system Dynamics part are linked by SuperCard's script. STELLA kernel is acting like a communication bridge between the program and the STELLA's model, carrying information to and during the simulation. The following section briefly explains how the program works.
- The program gets necessary information from the user to prepare suitability map(s)
- it gets initial value (s) from the user to run STEELA's model,
- it runs the model by sending data through STELLA kernel,
- it receives the feedback from the model through STEELS kernel,
- it uses new information to display the output geographically,
- the suitability map(s) is are updated,
- if the predefined condition (s) is (are) not satisfied, then the updated information will be used and step (c) will be repeated again .
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