BENEFIT ESTIMATION FOR ASSESSING THE GREEN ROOF EFFECTS ON NON-POINT POLLUTANT SOURCES MANAGEMENT: A CASE OF THE CHEONGGYECHEON WATERSHED, SOUTH KOREA

摘要

Non-point source pollution (NPSP) contributing to the total pollutant loads in 4 major river basins(Han, Geum, Nakdong, and Youngsan) in Korea was 42 - 69% in 2003 and it was estimatedto increase to 65 - 70% by 2015. Most local governments have focused on the expansion ofwastewater treatment plants (WWTP) to meet the goals of the current Total Water PollutionLoad Management plan, but the overall improvement of water quality will be limited only withpoint source reduction schemes. Policies for reducing NPSP exist for agro-industrial areas,but it is lacking for urban areas. A green roof is one of the sustantive management alternativesfor mitigating NPS discharges, which have increased due to urbanization. Although technicallyviable, it is necessary to assess its economic viability, as green roof projects require a largebudget. Four scenarios were established to: (1) analyze the effectiveness of green roofsfor alleviating non-point source pollution; (2) present the economic analysis criteria; and (3)estimate benefi ts by using the replacement cost approach.