EGG : A GEOGRAPHIC INFORMATION SYSTEM USING OBJECT - ORIENTED ' CONCEPTSt

In this paper, we design. and implement a ge?graph,ic information' system using obJect-onented concepts, named EGG (EXODUS-GOOD-GRACE), that consists of the User Interface layer, the Data Manager layer, and the Storage Manager layer. The User Interface layer (GRACE : Graphic User Interface for GIS) allows the administrator to l118nage geographic data easily and pennits the end users to displays the results clearly, the Storage Manager layer (EXODUS Storage Manager) storeS and retrieves a lot of geographical data efficiently, and the Data Manager layer (GOOD : Geo-Object Oriented Data Manager) connects the two layers. Since the query !anguage approach is not suitable for an API of GOOD, we implement GOOD as a library of callable functions. In order to develop the' EGG geographic information system, we first analyze eacli of the' layers well enough and then implement the individual layers by using suitable development tools. Lastly, we deve10p the comp1ete EGG geographic information system by combining the three layers. Since the layered approach provides transparency and reusability, it can reduce time and efforts in developing future GIS