• Journal of Korean Society of Water and Wastewater
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• v.29 no.2
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• pp.223-231
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• 2015

District Metered Area (DMA) construction is one of the most cost effective alternatives for management of water loss (i.e., water leakage) and energy consumption (i.e., water pressure) in water distribution systems. Therefore, it's being implemented to numerous new and existing water distribution systems worldwide. However, due to the complexity of water distribution systems, especially large-scale and highly looped systems, it is still very difficult to define the optimal boundary of DMAs considering all the aspects of water distribution system management requirements. In this study, a DMA design methodology (or a DMA design model) was developed with Geographic Information Systems (GIS) and hydraulic distribution system model to determine the optimal DMA boundary.

• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.761-767
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• 2010

This study introduces a model of territorial analysis on Chungcheongnam-do Nonsan-chun valley area, which gives an example of a method of selecting the management area for non-point pollution source from land use to help eliminate its source. High discharge load per unit area signify high level of land ratio with high level of basic unit of development load (including factory sites, school sites, roadways), which mean that there are a significant level of urbanization. It is these areas with the examination of the water quality of the nearby river that should be considered as the management area for non-point pollution source. Thus, the management area for non-point pollution source should be sought in areas with high discharge load per unit area and high density of water pollution area. When level of drainage is high the pollution density level is relatively lower, and when the level of drainage is low the density level is relatively higher. The level of pollution from non-point pollution source is much lower with more water flowing through. The possible non-point pollution source areas that were selected with these standards were then examined with the distance from the river, the slope angle, land usage, elevation, BOD discharge density load, T-N discharge density load, T-P discharge density load, and were given a level one through five. Out of the possible areas Nonsan-si Yeonmu-eup Anshim-li was the densest area, and it was given level one. The level one area should be examined further with the field analysis to be selected as the actual management area for non-point pollution source.

• Korean Journal of Geomatics
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• v.2 no.1
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• pp.37-46
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• 2002

Accurate classification of water area is an preliminary step to accurately analyze the flooded area and damages caused by flood. This step is especially useful for monitoring the region where annually repeating flood is a problem. The accurate estimation of flooded area can ultimately be utilized as a primary source of information for the policy decision. Although SAR (Synthetic Aperture Radar) imagery with its own energy source is sensitive to the water area, its shadow effect similar to the reflectance signature of the water area should be carefully checked before accurate classification. Especially when we want to identify small flood area with mountainous environment, the step for removing shadow effect turns out to be essential in order to accurately classify the water area from the SAR imagery. In this paper, the flood area was classified and monitored using multi-temporal RADARSAT SAR images of Ok-Chun and Bo-Eun located in Chung-Book Province taken in 12th (during the flood) and 19th (after the flood) of August, 1998. We applied several steps of geometric and radiometric calculations to the SAR imagery. First we reduced the speckle noise of two SAR images and then calculated the radar backscattering coefficient $(\sigma^0)$. After that we performed the ortho-rectification via satellite orbit modeling developed in this study using the ephemeris information of the satellite images and ground control points. We also corrected radiometric distortion caused by the terrain relief. Finally, the water area was identified from two images and the flood area is calculated accordingly. The identified flood area is analyzed by overlapping with the existing land use map.

• KIEAE Journal
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• v.13 no.4
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• pp.33-41
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• 2013

The impervious area on the surface of urban area has been increased as buildings and artificial land cover have continually been increased. Urban development has gradually decreased the green zone in downtown and alienated the city from the natural environment on outskirt area devastating the natural ecosystem. There arise the environmental problems to urban area including urban heat island phenomenon, urban flood, air pollution and urban desertification. As one of urban plans to solve such problems, green roof system is attracting attentions. The purpose of this study was to investigate flood discharge and heat reduction effect according to the green roof system and to quantify effect by analyzing through simulation water and heat cycle before and after green roof system. For the analysis, Distributed hydrologic model, WEP (Water and Energy transfer Processes) and WEP+ model were used. WEP was developed by Dr. Jia, the Public Works Research Institute in Japan (Jia et al., 2005), which can simulate water and heat cycle of an urban area with complex land uses including calculation of spatial and temporal distributions of water and heat cycle components. The WEP+ is a visualization and analysis system for the WEP model developed by Korea Institute of Construction Technology (KICT).

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.6
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• pp.820-828
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• 1999

The purpose of this study was to investigate the changes of pore area and water vapour transport by the changes of moisture regain and fabric structure of wool fabrics, As specimens 4 worsted wool fabrics were used. The pore area were measured by image analysis method and dinamic vapour transport and water reisitance was determined by clothing-environment-body modelling system. The pore area was changed by the moisture regain of wool fabrics. The change of pore area was influenced by the yarn twist thread count and cover factor and the weave type. The water vapour transport was changed by the moisture regain. The change of water vapour transport was influenced by the change of pore aree which was determined by image analysis.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.21-24
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• 2001

As one of the phil-environmental alternative plan of Saemankeum project, gradual development is recommended. The procedure of the Saemankeum project start with the completion of 32 km long sea-dikes which contains two discharge gates until the year 2004. Second step is pre-development of Mangyoung area permitting temporary intrusion of sea water, i.e. tides, by the opening of discharge gate until the environmental evaluation on the water quality of this area secures permanent meet to government's water quality standard. Therefore this study is to predict the future condition of this tidal flat with the point of view tidal environments, salt, water quality, soil mechanics, etc. of Mangyoung area when the sea water still passed in the inland reservoir through the discharge gate.

• Journal of Environmental Science International
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• v.17 no.3
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• pp.269-273
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• 2008

The objective of this study was to evaluate the relationship between nutrients and phytoplankton. This study was done by the comparison to two costal areas Mokpo, which inflow fresh water, and Wando. In August, salinity of the sea water decreased by 3.5-4.5%o in Mokpo coastal area, but was not nearly decreased in Wando coastal area. This suggests a lot of fresh water inflow in Mokpo coastal area. DIN and DIP were decreased by water temperature increasing in Wando. However, in Mokpo, DIN and DIP were increased greatly during the summer season. Nitrogen was limited to a 10 NIP ratio especially during the summer season in Wando coastal area while phosphorus in Mokpo coastal area was limited with over 28 N/P ratio in all the seasons. Coefficient of determination$(r^2)$ between DIP and Chl.-a was 0.91 in Mokpo coastal area. On the other hand, Coefficient of determination$(r^2)$ between Chl.-a and DIN, DIP were 0.93 and 0.89, respectively, in Wando coastal area. These results suggest DIP in Mokpo and DIN and DIP in Wando might be limited at the increase of phytoplankton.

• KIEAE Journal
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• v.13 no.1
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• pp.9-15
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• 2013

This study aims to analyze, by forming an experimental area of artificial soil green area that is of equal scale and analyzing the characteristics of runoff water in accordance with the cross-section configuration, applied the benefits in an actual multi-housing case study complex. In examining the measurement test results of the runoff water infiltration amount and surface runoff amount of a low-profile type green area(Dish type) and a general type green area(Mound type), Dish type was seen to have 1.5-times higher runoff water infiltration amount than Mound type during heavy rainfalls and showed about a 50% reduction with respect to the surface runoff amount. In other words, artificial soil green area offers the benefit of reduction of surface runoff amount and suggests, in actuality even with a change to the cross-sectional configuration of artificial soil green area alone at the time of construction of multi-housings, the possibility of benefits and reduction of costs spent on existing rainwater management facilities.

• Journal of Environmental Science International
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• v.17 no.2
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• pp.257-267
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• 2008

Groundwater recharge characteristics in a fractured granite area, Mt. Geumjeong, Korea. was interpreted using bedrock groundwater and wet-land water data. Time series analysis using autocorreclation, cross-correlation and spectral density was conducted for characterizing water level variation and recharge rate in low water and high water seasons. Autocorrelation analysis using water levels resulted in short delay time with weak linearity and memory. Cross-correlation function from cross-correlation analysis was lower in the low water season than the high water season for the bedrock groundwater. The result of water level decline analysis identified groundwater recharge rate of about 11% in the study area.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.3
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• pp.34-40
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• 1994

Industrial Complex in Ulsan is one of the most important areas in the nation. It includes ship building, automobile production, petroleum industry, non-metalic industry, and related industries. However, water for drinking and industry use has been and will be short seriously. Thus available drinking water sources were searched. By rebuilding the two existing dams 20m higher than the present levels, $500,000m^3/day$(for 200days) of water sources may be produced. Additional volume of $13,000m^3/day$(for 200days) can be obtained by a number of small dam construction in the vincity area. Underground water of about $50,000m^3/day$ may also be available. The total of $680,000m^3/day$ could be produced in Ulsan area, which is enough for the population of 1,200,000 in Ulsan area even after year 2011. This newly searched volume of water may be free from pollution. Raising the dam levels may also prevent Ulsan city from chronic flooding problems. Additional advantage is that as much as the newly developed water resources can be supplied to the industrial complexes.