• Korean Journal of Environment and Ecology
• /
• v.22 no.3
• /
• pp.320-324
• /
• 2008

This study was conducted to investigate abundance of breeding birds in relation to forest environment, to figure out the influential factors in abundance of breeding birds and to get the basic data for effective management of the bird community in Jirisan National Park. For this purpose, this research selected 4 main hiking trails as survey points and conducted a survey on breeding bird species and forest environment from April to August in 2007. The study results are as follows: The number of the birds observed during the breeding season was 33 species at the elevation of 300 meters to 1,900 meters. This research made a regression analysis of 13 bird species appearing at more than 30% of all surveyed points, species richness, and richness in the number of individuals. As a result of making a simple and multiple regression analysis of the factors, among the forest environment factors, that have an effect on richness in bird species, each species was found to be less influenced by an elevation. In addition, this analysis revealed that among the forest environment factors, coverage of tree-1 layer(>12m), tree height, coverage of shrub layer(2${\sim}$0.5m), slope, coverage of subtree-2 layer(4${\sim}$2m) appeared as more influential ones on the variation of abundance in more species than an elevation itself. That explains why it is necessary to continuously maintain and manage the coverage of tree-1 layer(>12m), tree height, coverage of shrub layer(2${\sim}$0.5m), slope, and coverage of subtree-2 layer$(4{\sim}2m)$, etc. for the preservation and management of bird species in a breeding season at Jirisan National Park.

• Korean Journal of Agricultural Science
• /
• v.29 no.2
• /
• pp.10-19
• /
• 2002

This study was conducted to investigate the avifauna of Gap stream in Daejeon metropolitan city from September in 2001 to August in 2002. For the monthly change of bird community, survey was carried at study area per each month, the obtained results could be summarized as follows. 1. The observed birds were 12 orders 31 families 83 species and 15900 individuals, 38 species are water bird as Herons, Dabbling ducks, Diving ducks, Rails, Sandpipers & Plovers and 45 species are land bird as Raptors, Woodpeckers, Wagtails, Thrushes, Warblers, Tits, Buntings, Crows. 2. These birds could be divided 29 residents, 29 summer visitors, 18 winter visitors, 7 passage migrants. 3. Among the birds, Chinese Sparrowhawk Accipiter soloensis, Eurasian Sparrowhawk Accipiter nisus, Kestrel Falco tinnunculus are legally protected species as natural monuments in Korea. 4. The major dominant species were Common Teal Anas crecca, Spot-billed Duck Anas poecilorhyncha, Mallard Anas platyrhynchos, Grey Heron Ardea cinerea, Magpie Pica pica, Little Egret Egretta garzetta in order, Gap stream should be appropriate habitats for dabbling ducks and herons. 5. Among the total number of 83 species, the highest number of species was 37 species in February and the lowest number of species was 27 species in June. 6. Among the total number of 15900 individuals, the highest number of individuals was 2899 individuals in December and the lowest number of individuals was 385 individuals in May. 7. Among the monthly species diversity index, the highest number of species diversity index was 2.6207 in September and the lowest number of species diversity index was 2.0716 in January.

• Journal of Environmental Health Sciences
• /
• v.28 no.3
• /
• pp.1-8
• /
• 2002

The experiments for the characterization of inactivation were performed in a series of batch processes with the total coliform as a general indicator organism based on chlorine, chlorine dioxide and ozone as disinfectants. The water sam-ples were taken from the outlet of settling basin in a conventional surface water treatment system that is provided with the raw water drawn from the mid-stream of the Han River. The inactivation of total coliform was experimentally ana-lyzed for the dose of disinfectant contact time, pH, Temperature and DOC. The nearly 2.4,3.0,3.9 log inactivation of total coliform killed by injecting 1 mか1 at 5 minutes for chlorine, chlorine dioxide and ozone. For the inactivation of 99.9%(3 log), Disinfectants required were 1.70, 1.00 and 0.60 mか1 for chlorine, chlorine dioxide and ozone, respec-tively. The higher the pH is, the poorer the disinfections effects are in the range of pH 6-9 by using chlorine and ozone. But the irfluence of pH value on killing effects of chlorine dioxide is weak. The parameters estimated by the models of Chick-Watson, Hom, and Selleck from our experimental data obtained for chlorine are: log(N/ $N_{0}$ )=-0.16 CT with n= 1, log(N/ $N_{0}$ )=-0.71 $C^{0.87}$T with n$\neq$1, for Chicks-Watson model, log (N/ $N_{0}$ )= -1.87 $C^{0.47}$ $T^{0.36}$ for Hom model. For chlorine dioxide are: log(N/ $N_{0}$ )= -1.53 CT with n = 1, log(N/ $N_{0}$ )= -2.29 $C^{0.94}$T with n$\neq$1,, for Chicks-Watson model, log(N/ $N_{0}$ )= -3.64 $C^{0.43}$ $T^{0.24}$ for Hom model and for ozone are: log(N/ $N_{0}$ )= -2.59 CT with n = 1, log(N/ $N_{0}$ )= -2.28 $C^{0.36}$T with n$\neq$1, for Chicks-Watson model, log(N/ $N_{0}$ )= -4.53 $C^{0.26}$ $T^{0.19}$ for Hom model.19/ for Hom model.

• Journal of Korean Society of Forest Science
• /
• v.102 no.3
• /
• pp.398-406
• /
• 2013

Afforestation/reforestation (A/R) clean development mechanism (CDM) is the only forestry-based activities allowed under the Kyoto protocol. This study was conducted to develop a methodology to estimate greenhouse gas (GHG) removals of a small scale A/R CDM pilot project in Goseong, Gangwon Province, Korea. AR-AMS0001 was applied as a methodology and selected tree species were Pinus koraiensis, Larix kaempferi, and Betula platyphylla for total area of 75.0 ha. To improve the accuracy on the GHG removals estimation, selection of the baseline scenario and carbon pools and stratification of the project site were conducted. Based on the developed methodology, net anthropogenic GHG removals were estimated as actual net GHG removals, subtracted by baseline net greenhouse gas removals and leakage. As a result, anthropogenic GHG removals of the project were 12,415 ton $CO_2-e$ and 165.5 ton $CO_2-e/ha$. This project is the first A/R CDM in domestic site and could enhance the technical accuracy of the GHG removals estimation by using countryspecific data reflecting the site condition.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.4
• /
• pp.1413-1424
• /
• 2013

Recently, the frequency of severe storms increases in Korea. Severe storms occurring in a short time cause huge losses of both life and property. A considerable research has been performed for the flood control system development based on an accurate stream discharge prediction. A physical model is mainly used for flood forecasting and warning. Physical rainfall-runoff models used for the conventional flood forecasting process require extensive information and data, and include uncertainties which can possibly accumulate errors during modelling processes. ANFIS, a data driven model combining neural network and fuzzy technique, can decrease the amount of physical data required for the construction of a conventional physical models and easily construct and evaluate a flood forecasting model by utilizing only rainfall and water level data. A data driven model, however, has a disadvantage that it does not provide the mathematical and physical correlations between input and output data of the model. The characteristics of a data driven model according to functional options and input data such as the change of clustering radius and training data length used in the ANFIS model were analyzed in this study. In addition, the applicability of ANFIS was evaluated through comparison with the results of HEC-HMS which is widely used for rainfall-runoff model in Korea. The neuro-fuzzy technique was applied to a Cheongmicheon Basin in the South Han River using the observed precipitation and stream level data from 2007 to 2011.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.2
• /
• pp.119-126
• /
• 2014

The object of this study was to evaluate the combined toxic interactions of the perfluorooctanoic acid (PFOA) or perfluorooctane sulfonate (PFOS) with six heavy metals (Cu, Zn, Cr, Cd, Hg, and Pb). The individual and combined toxic effects were assessed using the Vibrio fischeri assay. In case of the individual toxicity, PFOA was higher toxic than PFOS and toxicity of PFOA and PFOS were lower than heavy metal. In the toxicity of heavy metals, the $Hg^{2+}$ was found to be most toxic followed by $Pb^{2+}$, $Cr^{6+}$, $Cu^{2+}$, $Zn^{2+}$, and $Cd^{2+}$. The combined toxicity of PFOA or PFOS with $Cr^{6+}$ were synergistic effect because the $EC_{50}$ mix values were less than 1 TU. PFOA + $Zn^{2+}$, PFOS + $Zn^{2+}$, PFOA + $Cd^{2+}$ and PFOS + $Cd^{2+}$ produced addictive effect. Except in these case, all of binary mixtures show antagonistic effect. This study proved potential risk of coexistent with perfluorinated compounds and heavy metals in water environment.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.1
• /
• pp.58-66
• /
• 2014

Water pollution problems of urban rivers due to the urbanization and industrialization have been the subject of public attention. In particular, considering the fact that the characteristics of water cycle of each basin change dramatically through the development of new towns, a large number of concerns about future water quality have been raised. However, reasonable measures to predict future water quality quantitatively have not been presented by this moment. In this study, by the linkage of annual unit load generation based on long-term monitoring results of the ministry of environment (MOE) to a semi-distributed rainfall runoff model, SWMM (Storm Water Management Model), we proposed a new methodology to estimate future water quality macroscopically and testified it to verify its applicability for the estimation of future water quality of a small watershed at G new town. As a result of the estimation using Y-EMC (Yearly based Event Mean Concentration), future water quality were simulated as BOD 18.7, T-N 16.1 and T-P 0.85 mg/L respectively which could not achieve the grade III of domestic river life guidance and these criteria could be satisfied by the reduction of domestic wastewater discharge load by over 80%. The results of this study are shown to be utilized for one of basic tools to estimate and manage water quality of urban rivers in the course of new town developments.

• Journal of Korea Water Resources Association
• /
• v.40 no.6 s.179
• /
• pp.459-468
• /
• 2007

To estimate the groundwater recharge, the fully distributed parameter based model, MIKE SHE was applied to the Gyeongan-cheon watershed which is one of the tributaries of Han River Basin, and covers approximately $260km^2$ with about 49 km main stream length. To set up the model, spatial data such as topography, land use, soil, and meteorological data were compiled, and grid size of 200m was applied considering computer ability and reliability of the results. The model was calibrated and validated using a split sample procedure against 4-year daily stream flows at the outlet of the watershed. Statistical criteria for the calibration and validation results indicated a good agreement between the simulated and observed stream flows. The annual recharges calculated from the model were compared with the values from the conventional groundwater recession curve method, and the simulated groundwater levels were compared with the observed values. As a result, it was concluded that the model could reasonably simulate the groundwater level and recharge, and could be a useful tool for estimating spatially/temporally the groundwater recharges, and enhancing the analysis of the watershed water cycle.

• Journal of Environmental Impact Assessment
• /
• v.8 no.1
• /
• pp.107-120
• /
• 1999

This study was performed to survey the general feature of reservoir sediment in Daecheong, Sapkyo and Kumkang reservoir. For investigations, sediments were sampled at four sites in Dae-Cheong and two sites in SapKyo and Kumkang in June and October. The items for investigation are as follows; water content, loss on ignition(IG), porosity of sediment, contents of element such as hydrogen, nitrogen, carbon, phosphorus contents and nutrient release rates. Loss on ignition was measured to determine the contents of organic substance. And its ranges were determined 2.4~16.2% in Daecheong reservoir, 5.6~27.9% in Sapkyo and 4.8~18.7% in Kumkang reservoir. And, total phosphorus contents in sediments were measured $677{\sim}5,238{\mu}g/g$ in Daecheong, $780{\sim}1,417{\mu}g/g$ in Sapkyo and $604{\sim}1,452{\mu}g/g$ in Kumkang reservoir. And release rates of nutrients were calculated $0.05{\sim}8.63mgP/m^2day$ and $4.99{\sim}36.56mgN/m^2day$ in Daecheong, $1.83{\times}10^{-3}{\sim}3.23{\times}10^{-2}mgP/m^2day$ and $1.97{\sim}.22mgN/m^2day$ in Sapkyo, $8.31{\times}10^{-3}{\sim}6.51{\times}10^{-2}mgP/m^2day$ and $0.89{\sim}4.42mgN/m^2day$ in Kumkang reservoir, respectively. And this study attempted to determine the humus level of sediments. As a result of elemental analysis, C/N ratio was determined 3.0~13.1 in Daecheong reservoir, 6.5~13.0 in Sapkyo and 3.6~12.6 in Kumkang reservoir, respectively. From the elemental analysis, humus levels of reservoirs were changed from mesohumic to oligohumic state in all reservoirs.

• Journal of Korea Water Resources Association
• /
• v.37 no.8
• /
• pp.653-662
• /
• 2004

In this study, the method of Increasing the flood control as well as conservation effects is studied by joint operation of Hwacheon and Peace Dam. After completing the second phase of the construction of the Peace Dam, the dam crest height will be increased from 225m and the storage capacity will also be increased. If storage capacity is increased and gates are installed, it will assist not only flood control but also conservation of the entire Han river basin. Considering the change of conservation levels, the change of the restricted water level of the Hwacheon Dam in flood season, and the inflow change into the Peace Dam through the simulated reservoir operation, the annual average power of Hwacheon Dam with 95% reliability, annual firm power, the volume of water supply is calculated. As a result, when the conservation level of the Peace Dam and the restricted water level of the Hwacheon Dam are increased, the generation capacity will be improved. However, even though the inflow decrease, the generation capacity will not be affected. If the inflow decrease under the same conditions, the water supply capability will be reduced to the range from 35% to 40%. It is necessary to increase conservation level to keep the same water supply capability.