• Journal of Korea Water Resources Association
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• v.42 no.9
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• pp.737-745
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• 2009

Field measured sediment yield from an experimental urbanized basin was compared with the predicted sediment yields with RUSLE (Revised Universal Soil Loss Equation), and MUSLE (Modified Universal Soil Loss Equation). The experimental basin is 3.1km2 in area and fifty six percent of the total area had been urbanized. The hydrological data have been measured with T/M at the outlet of the experimental basin. Runoff from the basin and rainfall depth of the basin were measured every minute. Bed load and suspended load were also measured for a given flow rate. Runoff rating curves and sediment rating curve were developed for the last three years. RUSLE showed scattered prediction results but the average of the prediction values was close to the measured one. Meanwhile, MUSLE showed linear correlation between the measured sediment yield and predicted one with high correlation coefficient. But MUSLE predicts high values than the real one. Therefore, adjustment is necessary to apply MUSLE in estimation of sediment yield from the experimental urbanized basin.

• Water for future
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• v.29 no.3
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• pp.153-161
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• 1996

This study is runoff analysis of the recently urbanized San Bon basin. The relationships between peak discharge and total discharge were examined by applying the ILLUDAS runoff analysis model to the measured data. In urbanized streams, it is found that channel adjustment had the most significant effect on the increase of peak discharge. Significant increases in the peak discharge occurred as rainfall duration or return period increases 10% and 7~16% increases in peak discharge were observed when the roughness coefficient were 0.04 and 0.015, respectively. When the natural river channel with n=0.04 was converted into a sewerage system of n=0.015 the peak discharge was greatly increased by 51~158%, Generally, flood peak discharge was increased during heavy rain, but in the case of urbanized basin, river stage was reduced owing to an increase of flow velocity by the adjustment of drainage system.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.4
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• pp.89-93
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• 2010

It is well known that the drastic change of hydrological characteristics of an urbanized basin causes severe runoff, sediment yield, and peak flow. High vulnerability of urban flood disasters is caused by land-use change and development of a basin. A typical site suffering urbanization was selected and the experimental site has being operated last three years. Hydrological and hydraulic characteristics of the urbanizing basin were examined by observation of runoff, sediment loads and precipitation with T/M. The effects of land-use change were analyzed by examination of the hydrological characteristics, such as run-off ratio (runoff volume/rainfall volume), sediment yields. Runoff coefficient of rational equation was increased as basin was urbanized. Suspended sediment yields due to a urban development activities were raised almost 10 times compare to undisturbed condition for small runoff less than 1 cms. Meanwhile, no big change could be detected for bed loads.

• Journal of the Korean association of regional geographers
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• v.12 no.1
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• pp.1-15
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• 2006

This study is to review the site of Seoul and its urbanized area expansion in relation with a geomorphic environments. Surveying on the urbanized area of Seoul by period and related geomorphic conditions found the following conclusions. Seoul urbanized area had been expanded from the cheonggyecheon drainage basin to its surrounding hills and marshland. The marshland development began during the Japanese period from around the tributaries of the Hangang river and expanded to the areas by the main stream of the river. The extensive marshland at the point where the main stream and its tributaries of the river join has been developed relatively new. The marshland development, which took advanced engineering skills and a huge investment, is comparatively later and also involves large additional expenses to keep the areas from food damages. Judging from the above findings, this study concluded that the urbanized area expansions in a big metropolitan city such as Seoul, are greatly influenced by geomorphic environments and the importance of geomorphic conditions still hold true even today when scientific and technological developments have reached unprecedented heights.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.53-57
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• 2007

Tsurumi River Basin successfully started to prepare a Water Master Plan though a series of discussions by gathering all stakeholders in a hall. It began with setting five management targets namely, flood, low flow, natural environment, emergency use, and recreational use, followed by setting management goals by target as well as a one-sentence catchphrase for the Water Master Plan using a bottom-up approach. The author reviews this process and discusses the background of the success.

• Korean Journal of Environment and Ecology
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• v.26 no.2
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• pp.233-246
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• 2012

We need to analyze the ecological characteristics in the basin of agricultural reservoir that include urbanized area, agricultural area and fringe area, etc. The purpose of this study is not only that presenting the methods of basin ecosystem management but also suggesting ecosystem management plan proposals for the water quality based on analysis of ecological characteristics. As the results of analysis, the urbanized area(the ratio of area(ROA): 14.0%) is most likely to possibility of water pollution, then followed by paddy fields(ROA: 65.5%) where a wide spread up-basin(or up-stream), farmlands(ROA: 11.3%), farm buildings(ROA: 5.7%) and orchard(ROA: 3.9%). According to those, we investigated the impact degree of water pollutants. Thus, we were able to classify 5 types through considering the biotope assessment and the hydrosphere basin assessment, i.e. the level of priority control for source pollution. As a result, the source pollution intensive management area(11.3%) where are adjacent waterfront has caused water pollution, however, most importantly, it is necessary to control in source pollution management area(0.6%) that are away from waterfront. In conclusion, according to the these results, the plan of basin ecosystem management for the water quality should be included the plan of ecosystem conservation and restoration such as improving inhabitants function, controling environmentally sound basin management, promoting biodiversity.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.64-67
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• 2006

The main purpose of this research was to investigate the effects of urbanization on the groundwater system in the Gap river basin, a sub-basin of the Geum river basin. In this analysis, we constructed a water cycle analysis system using SWAT. Then, changes in soil moisture and recharge rate due to land-use changes were investigated using different land-use data estimated in 1975 and 2000. Simulation results were analyzed for both draught (2001) and flood (2003) years to take into account different hydrologic conditions. It was shown that recharge rate in the most urbanized area (31% change) was reduced by 17% for both periods due to urbanization. The results also indicated that soil moisture decrease due to urbanization was more sensitive in the drought year (2001) than in the flood year (2003), We expect that the results of this research can contribute to providing useful information for managing urban rivers considering river restoration and flood control.

• Journal of the Korean association of regional geographers
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• v.8 no.2
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• pp.229-246
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• 2002

This study is a contribution to the geographical understanding of Daejeon Area, playing the role of principal center of Choongchong Province. This area has been urbanized associated with Daejeon Basin, an important natural unit in the middle part of South Korea. In order to understand Daejeon Area in geographer's view, it is necessary to elucidate geomorphological environment of Daejeon Basin and urban expansion pattern associating with it. Our research is converged into dual objectives: one, description and interpretation of basin's landforms; other, urban expansion relating with geomorphological condition. Daejeon's urban expansion has progressed from the border zone of Daejeon Basin toward into the basin, and then vice versa. Relating to rivers valleys in the basin, the urbanization in the basin has been extended from the river valleys of lower order toward those of higher order. Understanding of the geomorphological mosaique of Daejeon basin is an important base for that of urban mosaique of Daejeon City.

• Journal of Korea Water Resources Association
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• v.36 no.1
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• pp.75-85
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• 2003

Urban rainfall-runoff procedures are more complex than the agricultural procedures due to the spreading and development of town. And the applications of theses models are more difficult due to the change of real basins. In this study, I applied SWMM and Expert System to get runoff characteristics of an urbanized basin. Noen in Daejeon is selected as a study basin. Real basin data of facilities, rainfall, runoff, and various rainfall intensity equations are used. An Expert System is used to get the parameters of this model. These results can be applied to analyze the reaction tendencies of the urban basin with the time distributions of design rainfall and the urbanization.

• Journal of Korean Society of Rural Planning
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• v.11 no.4 s.29
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• pp.47-57
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• 2005

The goal of this research is to evaluate landscape-ecological characteristics of watersheds in the Nakdong River Basin by using Geogaphic Information System (GIS) and landscape indices for integation of spatio-temporal informations and multivariate statistical techniques for quantitative analysis of forest landscape. Fragmentation index and change matrix techniques using factor analysis and grid overlay method were used to efficiently analyze and manage huge amount of information for ecological-environmental assessment (land-cover and forest landscape patterns). According to the results based on the pattern analysis of land-cover changes using the change detection matrix between 1980s and 1990s, addition on 750km$^2$ became urbanized areas. The altered 442.04km$^2$ was agricultural areas which is relatively easy for shifting of land-use, and 205.1km$^2$ of forests became urbanized areas, and average elevation and slope of the whole altered areas were 75m and 4$^{\circ}$. On the other hand, 120km$^2$ of urban areas were changed into other areas (i.e., agricultural areas and green space), and fortunately, certain amount of naturalness had been recovered. But still those agricultural areas and fallow areas, which were previously urban areas, had high potential of re-development for urbanization due to their local conditions. According to the structural analysis of forest landscape using the landscape indices, the forest fragmentation of watersheds along the main stream of the Nakdong River was more severe than my other watersheds. Furthermore, the Nakdong-sangju and Nakdong-miryang watersheds had unstable forest structures as well as least amount of forest quantity. Thus, these areas need significant amount of forest through a new forest management policy considering local environmental conditions.