• Title/Summary/Keyword: Urban Water

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Potential Effects of Urban Growth under Urban Containment Policy on Streamflow in the Gyungan River Watershed, Korea

  • Kim, Jinsoo;Park, Soyoung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.3
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    • pp.163-172
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    • 2015
  • This study examined the potential effects of urban growth on streamflow in the Gyungan River watershed, Korea, using urban containment scenarios. First, two scenarios (conservation and development) were established, and SLEUTH model was adapted to predict urban growth into the year 2060 with 20 years interval under two scenarios in the study area. Urban growth was larger under scenario 2, focusing on development, than under scenario 1, focusing on conservation. Most urban growth was predicted to involve the conversion of farmland, forest, and grasslands to urban areas. Streamflow in future periods under these scenarios was simulated by the Soil and Water Assessment Tool (SWAT) model. Each scenario showed distinct seasonal variations in streamflow. Although urban growth had a small effect on streamflow, urban growth may heighten the problems of increased seasonal variability in streamflow caused by other factor, such as climate change. This results obtained in this study provide further insight into the availability of future water resource and can aid in urban containment planning to mitigate the negative effects of urban growth in the study area.

A Modified Digital Elevation Modeling for Stormwater Management Planning in Segmentalized Micro-catchment Areas

  • Lee, Eun-seok
    • Journal of People, Plants, and Environment
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    • v.24 no.1
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    • pp.39-51
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    • 2021
  • Background and objective: Urban topology can be characterized as impervious, which changes the hydrologic features of an area, increasing surface water flow during local heavy rain events. The pluvial flooding is also influenced by the vertical structures of the urban area. This study suggested a modified digital elevation model (DEM) to identify changes in urban hydrological conditions and segmentalized urban micro catchment areas using a geographical information system (GIS). Methods: This study suggests using a modified DEM creation process based on Rolling Ball Method concepts along with a GIS program. This method proposes adding realized urban vertical data to normal DEM data and simulating hydrological analyses based on RBM concepts. The most important aspect is the combination of the DEM with polygon data, which includes urban vertical data in three datasets: the contour polyline, the locations of buildings and roads, and the elevation point data from the DEM. DEM without vertical data (DCA) were compared with the DEM including vertical data (VCA) to analyze catchment areas in Shin-wol district, Seoul, Korea. Results: The DCA had 136 catchments, and the area of each catchment ranged from 3,406 m2 to 423,449 m2. The VCA had 2,963 catchments, with the area of each ranging from 50 m2 to 16,209 m2. The most important finding is that in the overlapped VCA; the boundary of areas directly affected by flooding and the direction of surface water flow could be identified. Flooding data from September 21, 2010 and July 27, 2011 in the Shin-wol district were applied as ground reference data. The finding is that in the overlapped VCA; the boundary of areas directly affected by flooding and the direction of surface water flow could be identified. Conclusion: The analysis of the area vulnerable to surface water flooding (SWF) was more accurately determined using the VCA than using the DCA.

Development and Verification of Inundation Model Considering Storm Sewers in Urban Area (도시배수체계와 연계한 침수모형의 개발 및 검증)

  • Han, Kun-Yeun;Lee, Chang-Hee;Kim, Ji-Sung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.159-162
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    • 2005
  • Urban flooding is usually caused by the surcharge of storm sewers. For that reason, domestic studies about urban flooding are concentrated on the simulation of urban drainage system. However these approaches that find the pipes which have insufficient drainage capacity are very approximate and unreasonable ways. In this study, an accurate mathematical modeling is developed to analyze the impacts of an urban inundation for both flood prevention and flood-loss reduction planning and it is verified by using the simulation of July 2001 flooding in Seoul. The result of this study can be used to construct fundamental data for a flood control plan and establish a urban flood forecasting/warning system.

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A Study on Empirical Method Analysis of Impervious Surface Using KOMPSAT-2 Image (KOMPSAT-2 위성영상을 이용한 불투수지도작성 방법에 관한 실증연구)

  • Bae, Da-Hye;Lee, Jae-Yil;Ko, Chang-Hwan;Ha, Sung-Ryong
    • Journal of Environmental Impact Assessment
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    • v.20 no.5
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    • pp.717-727
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    • 2011
  • Impervious surface affects urban climate, flood, and water pollution and has important role as basic data for urban planning and environmental and resources management uses. With a high paved rate, increased quantity of the outflown water and brings urban flooding during a heavy rain. Moreover, these non-point source pollution is getting increased the water pollution. In this regard, it is definitely important to research and keep monitoring the current situation of paved surface, which influences urban ecosystem, disaster and pollution. In this study, we suggest a method to utilize high resolution satellite image data for efficient survey on the current condition of paved surface. We analysed the paved surface condition of Dae-jeon metropolitan city area using KOMPSAT-2 image and validate its practicalness and limitation of this method.

Comparison of Rainfall-Runoff Characteristics at Stream in Urban and Rural Watershed (도시 및 농촌 유역 하천에서의 강우유출 특성 비교)

  • Kim, Ho-Sub;Kim, Sang-Yong;Park, Yun-Hee
    • Journal of Korean Society on Water Environment
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    • v.34 no.6
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    • pp.650-660
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    • 2018
  • The objective of this study was to compare the rainfall-runoff characteristics in streams of classified urban and rural watershed using land use and population density. EMC (event mean concentration) of BOD, COD, TP and SS increased significantly in urban and rural watershed, but that of TN remained unchanged. Although there were no significant differences in EMC of BOD, COD, TN, TP depending on the watershed characteristics, EMC of BOD and COD significantly increased in the urban watershed, while EMC of TP increased in the rural watershed. In the urban watershed, the first flush time was faster and the first flush effect was stronger in BOD, COD, and TP. However, the difference between cumulative mass and cumulative volume was found to be less than 0.2 in the rural watershed, indicating a weak first flush effect. The discharged masses of BOD (70 %), COD (64 %), and TP (66 %) in the first flush of runoff were higher in urban watershed, while TN (67 %) was higher in rural watershed. The reproducibility of first flush time and the strength of first flush using CV (coefficient of variation) was found to be more reproducible for first flush time in both watersheds. In rural watershed, the CV value of first flush time for TP out of water quality parameters was lower. Whereas the CV values of first flush time for BOD, COD and TP in urban watersheds were similar.

Best Site Identification for Spatially Distributed On-Site Stormwater Control Devices in an Urban Drainage System (도시유역에서 공간적으로 분포된 소규모 강우유출수 관리시설의 최적설치위치선정)

  • Kim, Sangdan;Lim, Yong Kun;Kim, Jin Kwan;Kang, Dookee;Seo, Seongcheol;Lee, Jae Kwan
    • Journal of Korean Society on Water Environment
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    • v.26 no.6
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    • pp.986-993
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    • 2010
  • Spatially distributed on-site devices such as bioretentions and bioboxfilters are becoming more common as a means of controlling urban stormwater quality. One approach to modeling the cumulative catchment-scale effects of such devices is to resolve the catchment down to the scale of a land parcel or finer, and then to model each device separately. The focus of this study is to propose a semi-distributed model for simulating urban stormwater quantity and identifying best sites for spatially distributed on-site stormwater control devices in an urban drainage system. A detailed model for urban stormwater improvement conceptualization simulation is set up for a $0.9342km^2$.

A Study on the Application and Assessment of Urban River Restoration in the Anyang River (안양천 도시하천 복원의 실행과 평가에 관한 연구)

  • Lee, Sam-Hee;Choi, Jung-Kwon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.1
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    • pp.1-8
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    • 2007
  • The Anyang River which located in an urban area near Seoul had been managed focusing on supplying home and industrial water and preventing floods, coping with rapid industrialization and urbanization. Consequently, it was changed into a deadly river during 25 years. Its channel was straightened by concrete and water quality deteriorated to BOD 190mg/l. In addition, water quantity has been rapidly decreased and has been drying up. Also, as the river ecosystem, landscape, water-friendly function, and so forth were seriously deteriorated, people turn away from the urban river. From 2001, the master plan under the 10-year has been actively carried out centering on the preceding items, which are healthy river in which fishes inhabit, safe river free from floods and droughts, and pleasant river where citizens visit. As a result, its water quality was remarkably improved by BOD 5mg/l in 2005 and some upper zones were improved enough to allow people to swim. Moreover, various animals including fish and birds gather around the river. Now, the 'Anyang River Restoration Project' is recognized as the first comprehensive and systematic nature-friendly urban river improvement in Korea.