• Journal of Korean Society of Environmental Engineers
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• v.36 no.10
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• pp.691-697
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• 2014

Though the upper stream basin area of Gwanpyung-Cheon in Daejeon, Korea is protected as Green Belt Zone, the stream is under constant environmental pressure due to current agricultural practices and infrastructure development in its basin area. To develop appropriate integrated water resources management plan for the stream, it is necessary to consider not only water quality problems but also water quantity aspect. In this study, Storm Water Management Model (SWMM) was calibrated and validated with sets of field measurements to predict for future water flow and water quality conditions for any rainfall event. While flow modeling results showed good agreement by showing correlation coefficient is greater than 0.9, water quality modeling results showed relatively less accurate levels of agreements with correlation coefficient between 0.67 and 0.87. Hypothetical basin development scenarios were developed to compare effect on stream water quality and quantity when Low Impact Development (LID) technologies are applied in the basin. The results of this study can be used effectively in decision making processes of urban development Gwanpyung-Cheon area by comparing basin management alternatives such as LID methods.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.195-198
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• 2008

In this study we analyzed flood runoff and flood characteristics of an small urban river basin which is in an apartment complex in Yewol-Dong, Buchun-Si, Gyunggi-Do. A little discharge normally flows in the river, however this small river has a relatively high potential of flood damage risk in the flood season due to the high flood level and velocity. Therefore we used the GIS data, cross section data in the river, HEC-RAS model, etc. for investigating safety of a river against flood runoff and also we investigated the stability of hydraulic structures and ability of flood prevention in the river. As the result of investigation, we found that the river had the risk of flood damage occurrence due to the hydraulic structures constructed for various purposes in the river. So we should analyze backwater effect by the structures and consider the risk factors can be occurred by the flood runoff and velocity for more safe design of a small river basin in the residential area such as an apartment complex in the urban area.

• Korean Journal of Agricultural Science
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• v.2 no.1
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• pp.265-279
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• 1975

This study was conducted to investigate the development of Gab river-basin which was a part of the farm land enlargement to contribute to the increased production of food. The results were as follows; 1. Gab river has the upper stream which occupy 50 percent in moumtains and the mid-stream in the Daejeon city area, and the downstream in a field which is about 22.9 percent in which farming area per household is 0.82 ha., agricultural population is 76 percent except of Daejeon city. Also, urban enlargement of mid-stream basin and development of industrial area in the lower stream diminish farm land. Consequently, this area should be developed to farm land to increase farming size. 2. There is no possibility to develop farm land in mountains of which (64.9 percent) is forests and in midstream which was constructed river-improvement. But Weonjeong area and Yongcheon area will be effective area. 3. If river banks of Weonjeong area will make straight with cost of construction 195,000,000 won, bank length 6 km will be useless, water will flow smoothly, flood will be prevented, farm land will develop 21.66 ha in which rice will produce annually 81.698 M/T which is about 10,860,000 won. 4. This area has good conditions of development. that is, investment efficiency (B/C) is 1.47 more than 1.00. 5. This area is a multiple purpose development district. The reasons are that there are beautiful mountains and a reservoir to be expected to construct, so it will be a sight seeing district in the vicinity of Daejeon city. 6. If Honam railway double line and river straight construction had executed simultaneously, cost of construction 50,000,000 won would have saved.

• Journal of Soil and Groundwater Environment
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• v.8 no.2
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• pp.19-35
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• 2003

In order 새 investigate the spatial and seasonal variations of heavy metal pollution in heavily industrialized urban area, urban roadside sediments were collected for five years from gully pots in Seoul City. A series of studies have been carried out concerning the physicochemical characteristics of the sediments in order to evaluate the contamination of heavy metals such as Cd, Co, Cr, Cu, Ni, Pb and Zn. Roadside sediments and uncontaminated stream sediments were analyzed for total metal concentrations using acid extraction. The roadside sediments are characterized by very high concentrations of Zn (2,665.0$\pm$1,815.0 $\mu\textrm{g}$/g), Cu (445.6$\pm$708.0 $\mu\textrm{g}$/g), Pb (214.3$\pm$147.9 $\mu\textrm{g}$/g) and Cr (182.1$\pm$268.8 $\mu\textrm{g}$/g), indicating an artificial accumulation of these metals to the sediment chemistry. Comparing with average contents of uncontaminated stream sediments, roadside sediments were shown zinc 14 times (up to 64.4), copper 9 times (up to 181.7), lead 6 times (up to 63.7), cobalt 6 times (up to 168.7), nickel 4 times (up to 98.4), cadmium 2 times (up to 12.8) and chrome 2 times (up to 40.2) high content. The relative degree of heavy metal pollution for roadside sediments collected from each district in Seoul City is evaluated using the “geoaccumulation index”. As a result, heavy-metal contamination is highest centering the oldest residential district and industry area, and contamination level decreases as go to outer block of the city. The factor analysis results indicate that the levels of Cu, Ni, Fe and Cr are strongly related to numbers of factories, whereas the concentrations of Cr, Zn and Cd dependant on pollution index, indicating artificial contamination due to site-specific traffic density.

• Journal of Environmental Health Sciences
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• v.23 no.4
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• pp.1-8
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• 1997

The aquatic animals of Tan stream were composed of 46 species, 28 families, 11 orders, 6 classes in 4 phyla during the survey period of April, 1996 to December, 1996. They were composed of 31 species in aquatic insecta, 6 species in annelida, 3 species in mollusca, 1 species in crustacea, and 5 species in fishes, respectively. Major dominant species in Tan stream were Chironomidae sp.1, Chironomidae sp.2, Chironomidae sp.3, Tubufucidae sp.1, Physa acuta and hirudo niponica. Dominance indices of benthic macroinvertebrates ranged highly from 95.74 to 100.00% at lower stream(site 4), but ranged 50.00 to 95.85% at site 1 through site 3. The aquatic animals ranged from 25 to 32 species at site 1 through site 3, but they were only 3 species at site 4 for survey period. Tan stream in the light of urban stream ecosystem has a little less riffle areas and hydrophyte areas by cementation of riparian area and channel type of water course. Therefore, the species of aquatic animals in Tan stream decreased because of deterioration of water quality according to reduction of self-purifcation ability and loss of microhabitat according to reduction of hydrophyte areas and riparian areas. The tendency of decreasing species of aquatic animals appeared seriously at lower stream From drive licence test authority at Kangnam-ku, Seoul to conjunction point of the Han river.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.320-329
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• 2022

Urban areas in watersheds increase the impervious surface, and agricultural areas deteriorate the water quality of rivers due to the use of fertilizers. As such, anthropogenic land use affects the type, intensity and quantity of land use and is closely related to the amount of substances and nutrients discharged to nearby streams. Riparian vegetation reduce the concentration of pollutants entering the watershed and mitigate the negative impacts of land use on rivers. This study analyzes the data through correlation analysis and regression analysis through point data measured twice a year in spring and autumn in 21 selected damaged tributary rivers within the Han River area, and then uses a structural equation model to determine the area land use. In the negative impact on water quality, the mitigation effect of riparian vegetation was estimated. As a result of the correlation analysis, the correlation between the agricultural area and water quality was stronger than that of the urban area, and the area ratio of riparian vegetation showed a negative correlation with water quality. As a result of the regression analysis, it was found that agricultural areas had a negative effect on water quality in all models, but the results were not statistically significant in the case of urban areas. As a result of the model estimated through the structural equation, BOD, COD, TN, and TP showed a mitigation effect due to the accumulation effect of river water quality through riparian vegetation in agricultural areas, but the effect of riparian vegetation through riparian vegetation was found in urban areas. There was no These results were interpreted as having a fairly low distribution rate in urban areas, and in the case of the study area, there was no impact due to riparian forests due to the form of scattered and distributed settlements rather than high-density urbanized areas. The results of this study were judged to be unreasonable to generalize by analyzing the rivers where most of the agricultural areas are distributed, and a follow-up to establish a structural equation model by expanding the watershed variables in urban areas and encompassing the variables of various factors affecting water quality research is required.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.161-169
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• 2009

Rainfall-runoff procedures of urban area are more complicated than agricultural procedures. Extension and development of town leads to shift of the basin characteristics and it makes more difficult to use runoff models. In this study, the changes of hydrologic circumstances and the shape of hydrograph due to the urbanization in Cho-kyung river basin has been assessed which is the representative urban stream in Jeonju city. The urbanization can be classified as four typical year. The natural basin period(1924) that is before the urban development, the period of construction of Chonbuk National University campus (1963), the period of construction of residential area(1986), and urbanization process has been finally completed in 1995. The rainfall-runoff analysis has been carried out by Storm Water Management Model(SWMM) under condition of the basin characteristics and impervious area of each period. It was found that hydrologic characteristics such as river length, roughness coefficient, and coefficient of surface storage has been decreased. According to the land use change, the pervious area was decreased from 97.7% to 42%, while the impervious area was increased from 0.6% to 34%. The time of concentration was shorten from 90 minutes to 37 minutes. Along with decreasing the time of concentration, the peak discharge was increased from $4.37m^3/s$ to $111.13m^3/s$, and the runoff rate was also increased from 0.8% to 68%.

• Journal of Wetlands Research
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• v.7 no.1
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• pp.119-128
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• 2005

Sediment yield and sediment transport in a basin bring about decrease of conveyance by the change of bed section, and have an influence on an aggravation of water quality and freshwater ecosystem. This study is to analyze the characteristics of outflow sediment according to land-use in Mushim-cheon flowing through forest area, farmland area and urban area. The upper stream of Mushim-cheon consists of forest area and farmland area. The suspended sediment is observed through 10 rainfall events in 5 sites. As a result of analyzing characteristics of landuse, the site of Bangse-gyo takes up 69% of Mushim-cheon, and farmland area(27.1%) and forest area(63.7%) take up 90.8% in Bangse-gyo. Accordingly, these two areas have the high possibility to occur sediment. The suspended sediment of this site shows the highest concentration. Transferring to the downstream and the urban, the concentration of suspended sediment gets decreased. The suspended sediment occurred in the upper stream of Mushim-cheon prior to Bangse-gyo has an influence on the downstream, and has a slight influence on the urban area. Also relational formula about suspended sediemtn and discharge is leaded. As a result of this formula, $R^{2}$ is 0.506 in the upper stream and is 0.656 in the downstream.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.34-39
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• 2006

The land use pattern, water quality and vegetation were investigated in the six tributaries, including Hanggeumcheon and Satancheon of the Namhan hydrosphere, Iksancheon, Jeonjucheon and Gosancheon of the Mankyung hydrosphere as well as Jongeupcheon of the Dongjin hydrosphere. Forest and farmland area were extensive in Hanggeumcheon, Satancheon and Gosancheon. Farmland and livestock area were wide in Iksancheon. Jeonjucheon were occupied with broad urban. Industrial and urban area were extensive in Jongeupcheon. The loading amounts of biochemical oxygen demand (BOD), total nitrogen (T-N), total phosphorus (T-P) of Iksancheon and chemical oxygen demand (COD) of Jeonjucheon were determined to be very high, respectively. The quality of water in Hanggeumcheon, Satancheon and Gosancheon were determined to be good quality. The species diversity was lower in the down stream than in the upper stream except for the Gosancheon. Life form of plane were mostly perennial plane in the upper stream and annual plants in the down stream of rivers. It was estimated that there is high level of disturbance in the down stream of rivers. The quality of water was significantly correlated with farmland and forest area. In conclusion, human impact, such as farmland and housing lot exerted an influence on the disturbance of down stream and the water quality of rivers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6B
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• pp.683-690
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• 2008

The objectives of this study are to provide an observation-based urban flood prediction model and to evaluate their performance on a restored Cheonggye stream. The study area, which has its own unique hydrologic and flooding conditions that can be characterized the standard of flood occurrence by watergate opening and walk lane inundation, measured stream discharges at the 5 sites and watergate opening and walk lane inundation through the main stream since 2006. This study derived the relationship between precipitation intensity and watergate opening and walk lane inundation time by using the observations of 2006 and verified their performance on 2007 flood events. The result showed that the coefficients of determination are ranged on 0.57-0.75, which would be acceptable if considering the complexity of the area and the proposed model simplicity. It also suggested the continuous observation of these properties is required for further improvement of the models.