2005, Vol.14, No.3

Journal of Environmental Impact Assessment 2023 KCI Impact Factor : 0.51

pISSN : 1225-7184
https://journal.kci.go.kr/kseia

The purpose of this study is to develop a system, which estimates watershed pollutant loadingrate through the combination of GIS and computational mode. Also, the applicability of thisstudy was estimated by the application of the above system for Chuncheon City. The detailedresults of these studies are as follows;The pollutant loading estimation system was developed for more convenient estimation ofpollutant loading rate in watershed, and the system load was minimized by the separation ofestimation module for point and non-point source. This system on the basis of GIS is veryeconomical and efficient because it can be applied to other watershed with the watershed map.System modification is not needed.The pollutant loading estimation system for point source was developed to estimate thepollutant loading rate in watershed through the extraction of the proper data from all districtsand yearly data and the execution of spatial analysis which is main function of GIS. From theverification result of spatial analysis, real watershed area and the administrative districtareaextracted by spatial analysis were 1,114,893,340.15m2 and 1,114,878,683.68m2, respectively. Itshows that the spatial analysis results were very exact with only 0.001% error. The pollutant loading estimation system for non-point source was developed to calculate the pollutant loading rate through the overlaying of land-use and watershed map after the construction of new land-use map using the land register database with most exact land use classification. Application result for Chuncheon City shows that the proposed system results in one percent land use error while the statistical method results in five percent. More exact nonpoint source pollutant loading was estimated from this system.

This study was conducted to evaluate the efficiency of indoor air cleaners and to inform howto select them correctly to the users. The efficiencies of removing suspended bacteria per hourwere 64.3± 13.1% for filter, wet, and complex type, respectively, which showed the complextype was the most efficient. The removal efficiencies of formaldehyde (HCHO) after two hoursoperation of air cleaners showed 88.3% and 81.1% for filter and wet type, respectively. Theefficiency of complex type, with removal rate of 55.5~58.4%, was decreased after 30 minutesoperation. Therefore, it is recommended to perform over 60 minutes when doing air cleanercertification test for HCHO removal efficiency. Generally, air cleaners having low wind volumeshowed higher efficiency.All tested air cleaners had no potential for removing of volatile organic compounds (VOCs),which is toxic substances, and it is desirable to develop a device which can control thesesubstances. The results also confirmed that there was no ozone production from all tested aircleaners. And it is recommended to ventilate for 20 minutes every four hours to maintain 50%ventilation status.

This study was executed to know the best matrix of photochemical ozone reduction in themetropolitan area. For this object, we used the OZIPR(Ozone Isopleth Plotting Package forResearch) model for comparing the effectiveness of VOCs and NOx amount variation about theozone creation.Among the various ozone reduction scenarios, 50% reduction of VOCs from organic solventand road traffic respectively was the best matrix for ozone reduction.Although it needs more accurate assessment and confirmation of VOCs and NOx emissionamount data, according to existing data, the control of VOCs is the best way for photochemicalozone reduction in Seoul.