This study describes the full disaggregation process of emission inventory maps in support of environmental modeling studies in a geographical information system. Using a heuristic approach, appropriate algorithms were found to accelerate the computational disaggregation speed. The algorithms were based on scan-conversion algorithms employed in the field of computer graphics. Various algorithms were analyzed in terms of supporting emission inventories with different shapes, such as points, polylines and polygons. The algorithms were implemented by using Visual Basic, thereby enabling the efficiencies of the algorithms to be analyzed and compared with each other. For the disaggregation of polygon types, with the aim of increasing the resolution of an inventory map, we suggest the advanced polygon-disaggregation method with land use data. An air dispersion simulation was performed in order to compare the accuracy of the emission input data generated by existing disaggregation methods and the advanced method proposed in the present study.