2014, Vol.23, No.6

Journal of Environmental Impact Assessment 2023 KCI Impact Factor : 0.51

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

There is a Conjoint Analysis to estimate the environmental value of natural river restorationproject of Inchon Metropolitan City’s small River: Gong-chon Stream, Gul-po Stream, Seung-gi Stream,Jang-su Stream. In order to find out the optimal expense condition, we tried to estimate the possiblepayable amount. According to the analysis, almost all people are willing to pay 15,000 Won. In caseof the river types, the people liked 10 cm’s depth of water and there should be brook trail, convenient facilities and flood plain at the stream edge space. But it is impossible to build these facilities withminimum fare 15,000 Won per a household. If the necessary expenses set high, the tax resistance ofthe local residents will be increased. So, in consideration of the analytical results of the attribute level,we draw five alternatives. This study is based on the results of Incheon metropolitan City residents’survey, and there is Conjoint Analysis to estimate the environmental value of natural-type river projectof Incheon metropolitan City. If it is reflected the special assume factors of this study, and if there isexact environmental value estimation of the various river quality through different analysis, then itwill become a study of high utilizing.

When the water quality modelling is done with a manual calibration, it is possible thatthe researcher’s opinion may affect the objectivity of the research. Hence, the role of the automaticcalibration is highly important. This research applies a technique to automatically calibrate the waterquality parameters by implementing an optimization method. This involves estimating the optimumwater quality parameters targeting influential parameters towards the lake’s BOD, DO, Phosphorus,Nitrogen and Phytoplankton. To accurately calculate the water temperature and hydrauliccharacteristics of a deep, stratifying lake, EFDC, a 3-dimensional hydraulic model which can belinked to the WASP7 was applied. With EFDC, the segment of the lake is formed and utilized as aninput data of the WASP7. For the calibration of the water quality parameters of the WASP7, an for calibration, the normalized residuals of the observed and calculated values of DO, TN, CBOD wererelatively small and the three water quality variables were calibrated properly. Yet the accuracy of thecalibration of TP and Chl-a was relatively low.

The objective of this study was to propose the best methodology for estimating soilorganic carbon stocks during environmental assessment for development projects. We comparedthree methodologies which were developed by Korea Environment Corporation(2010), Korea ForestResearch Institute (2006), and Jin-Hyun Jung (1998). We found that the methodology developed byJin-Hyun Jung (1998) shows the worst performance and the methodology of Korea Forest ResearchInstitute (2006) does not reflect a variety of soil types and land use characteristics shown indevelopment project plans. Therefore, we propose that the methodology developed by KoreaEnvironment Corporation (2010) is the most reasonable one because it is internationally acceptedand used for local governments to make the inventory of greenhouse gases as well as to set up itsreduction strategy.