The basin environment has been seriously damaged by reckless development during the past half century.
The demand for management in the basin has increased, but the system for prediction and management is not
sufficient. Therefore, the aim of this study is to design a GIS-based water quality linkage system using the most
suitable simulation, HSPF (Hydrological Simulation Program-Fortran) in this basin of South Korea. To achieve this,
data of HSPF model for simulation and GIS data for spatial analysis is collected. And the system applied linkages
of the water quality model and GIS such as Loose coupling. Also, the major function of the system was designed
as a modular unit. Ultimately, the system is developed using development language of VB.NET from Microsoft and
ArcObjects component from ESRI based on design for a module unit. The water quality simulation system can be
supported to prediction and management for basin environment of Yeong-San River. In the future study, scenario
will be established using the result of HSPF model And will be expected to support to situation of future basin and
policy making.