|
|
|
Land Degradation
|
A Knowledge-Based Approach for Land
Evaluation using RS and GIS Techniques
5. System Design and Implementation
Based on the concepts of a KBS and a GIS a prototype GES has been developed. The program was written in C language and linked to the LWIS GIS software. The structure of the system is shown in Figure1. GIS contains a specific view of a certain part of the real world ! which means it should contain a database and the analysis tools to I be used in a given problem solution. The development of the I database was done by digitizing soil and topographic maps and into which satellite image was registered.
Fig l General Structure of the GES
In the image haze correction and enhancement techniques were applied. For the development of the GES simple frames have been used for the questions' display and the knowledge base was represented using "IF conditions THEN conclusion" statements. It is possible to manipulate all necessary procedures of the GIS from : within the GES. All attribute values have been conditionally collected. Knowledge on the study area has been first represented : as a O-A-V triplet and then normalized using an inference tree. : From the normalized tree the rules to be used for the hypotheses evaluation were hierarchically extracted. Slope and moisture r information were defined by the use of the above mentioned techniques (see section 4.2) and the related attribute values were ~ exported to the O-A-V triplet before the normalization. During the .slope and moisture determination in RS and GIS procedures the
appropriate parameters have been automatically suggested according, to the context of the area.
For the hypotheses evaluation forward chaining principle has been used and the procedure is described as follows:
The output is the map indicating the land suitability for wheat planting ( Figure 2)
Fig 2 Suitability Map for Wheat
6. Conclusions
The research was carried out to test the role an expert system approach in geo related processing in case of missing some facts. As seen from the analysis , knowledge of the accuracy of the
information required for the decision making is very important. The developed system is an early prototype and has many limitations. To Also forward chaining search has demonstrated its weakness. It stops when missing some facts. In this case, it is better to use backward chaining in the matching of the rules and forward j ; chaining in data processing.
References.
- Amarsaikhan, D., Gorte, B., 1992, Knowledge-based Approach to Update Land use Layer of an Operational GIS, Proceedings of ACRS, I Ulaanbaatar, Mongolia.
- Amarsaikhan, D., 1994, Fundamentals of KBS and Artificial Intelligence Approach in RS and GIS, Journal Informatics, 8,2-93,Ulaanbaatar, Mongolia.
- Ganzorig, M., Adyasuren, Ts., 1995, Application of RS and GIS for Ecosystem Monitoring and Management, Paper presented at the International Seminar on Space Informatics, Ulaanbaatar, Mongolia.'
- Jun Chen, Peng Gong, Newkirk, R.T., and Davidson, G., 1991, A Knowledge Based GIS for Zoning, Proceedings of European Conference. on GIS.
- Miller, D., and Morris, J., 1992, An ES and GIS Approach to Predicting Changes in the Upland Vegetation of Scotland, European Conference on GIS, 11-19.
- Matsuyama , T., 1987, Knowledge-based Aerial Image Understanding Systems and Expert Systems for Image Processing. I.E.E.E. Transactions on Geoscience and Remote Sensing, 25, 317-328.
|
|
|
|
|
|
|
