Site suitability analysis for riverbank filtration in the Han River, Korea

Riverbank filtration has been employed for water supply in many developed countries for more than 100 years. In Korea, riverbank filtration has drawn attention since 1990s as an alternative having potential to stably meet the ever-increasing water demand. Some cities located in the Nakdong River Basin are currently supplying water through riverbank filtration. This research is regarding the introduction of riverbank filtration for the city of Seoul in the Han River Basin. Site selection is a crucial part and it is the main concern of this work. Analytic Hierarchy Process (AHP), which selects the most optimal alternative by hierarchically classifying various attributes and then quantifying the importance of each attribute, was used to prioritize candidate locations. We developed a computer program, SASCU - an AHP-based program to assess the suitability for the conjunctive use of surface and ground water at a site. This Windows-based software is an integration of the information search system and the AHP modeling system, and was designed using Avenue (a script language of a GIS software - ArcView) and Visual Basic. We applied the developed software to candidate locations for riverbank filtration in the Han River. Even though it is not easy to find proper locations near and within the heavily urbanized city of Seoul, twelve terrace lands on the river were initially identified from the geologic standpoint, which were narrowed down to four according to available information and water quality. Suitability analysis was conducted for those four candidate sites. The Kwangnaru district showed advantages over other locations in terms of water quality and connectivity to the neighboring purification facility.