• Journal of Korean Society on Water Environment
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• v.30 no.1
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• pp.87-94
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• 2014

According to the technical guideline of water pollutant load management, the rainfall captured ratio which can be estimated by the empirical formula is an important element to estimate reduction loads of non-point pollutants water quality control basin. In this study, the rainfall captured ratio is altered to stormwater captured ratio considering its meaning in the technical guideline of water pollutant load management, and the new empircal formula of stormwater captured ratio is suggested. In order to do this, we calculate stormwater captured ratio by using the hourly rainfall data of seven urban weather stations (Busan, Daegu, Daejeon, Gangreung, Seoul, Gwangju, and Jeju) for 43 years. The regression coefficients of the existed empirical formula cannot reflect the catchment properties at all, because they are fixed values regardless of regions. However the empirical formula of stormwater captured ratio has flexible regression coefficients by runoff coefficient(C), so it is allowed to consider the characteristics of runoff in catchment. It is expected that reduction loads of storage based water quality control basin can be more reasonably estimated than before.

• Journal of Wetlands Research
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• v.14 no.2
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• pp.181-192
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• 2012

Dae Dong Stream basin has been selected and operated as a representative experimental basin of UNESCO IHP since year 2007. It is located at Daejeon Metropolitan city, Korea and hydrologic data such as precipitation, runoff, and water quality have been being collected and provided after establishing the monitoring plan as an experimental basin for city/disaster prevention. In this study, runoff characteristics for non-point sources of rainfall-runoff process from urban stream basins were analyzed using the flow and water quality data measured during the year 2011. As an operation result for the test subjected basin, rating curves at Panam Bridge and at Chulgap Bridge were prepared, and to compare runoff characteristics of non-point source by precipitation, by estimating the Event Mean Concentration(EMC) for 10 water quality items, runoff characteristics of non-point source per different observation points as per the precipitation, antecedent rainfall, and land utilization status were analyzed.

• Journal of Korea Water Resources Association
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• v.41 no.5
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• pp.463-471
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• 2008

The purpose of this study is to analyze the features of groundwater use to utilize as basic information for water-cycle analysis system development and effective groundwater management in the Kap-cheon basin. The cumulative relationship between groundwater use and the number of wells was analyzed to estimate the representative total groundwater use and the number of wells for the Kap-cheon basin. Then, the spatial distribution of groundwater use in the basin were figured out using the detailed information on groundwater use in each well. Finally, the reasonability of groundwater resources management in Kap-cheon basin was evaluated by comparing groundwater recharge and groundwater use in sub-basins and major stream basins. The results of the analysis showed about 25% of the total wells could represent 90% of groundwater use ($37,923,516\;m^3$/year) in the Kap-cheon basin. A detailed analysis on the groundwater uses in the vicinity of down-town areas of Daejeon metropolitan city showed high groundwater uses ($1.4{\sim}11.1$ times) compared to the groundwater recharge previously estimated using the rainfall-runoff model. The ratio of groundwater use and groundwater recharge for the major river basins in Kap-cheon basin ranged from 1.9 to 2.3 indicating that more sustainable groundwater management should be exercised. The results of this study can be used as basic information in evaluating the change of groundwater flow, stream flow and water-cycle for various groundwater uses in the Kap-cheon basin.

• Korean Institute of Interior Design Journal
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• no.41
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• pp.121-128
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• 2003

This study was purposed to find that the elderly in Daejeon city evaluated design details in bathroom, stairway, entrance etc. On the base of housing expenses and an administrative district, the elderly over 65 were chosen and interviewed by well-trained investigators and 583 case was analyzed through SPSS PC 10.0. The results of this study were as follows ; they said a bathtub was necessary, the floor was not slippery, the height of basin was not high and the grab bar around toilet was not in bathroom and emergency bell was not in house. The elderly pointed out that the non-slip floor, grab bar, bathtub in bathroom and non-slip floor in entrance and stairs should be designed carefully. By the condition of the elderly' health and independent daily living and experience of housing, the evaluation of importance on bathroom and approach design by the elderly were different.

• Journal of Korean Society on Water Environment
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• v.35 no.5
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• pp.399-408
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• 2019

The average annual water quality at Yongchon Bridge, Bonggok 2 Bridge, and Gasuwon Bridge in upstream of Gapcheon in 2018 was Ib grade (good) in organic matters, including BOD and TOC compared to the local environmental standard in Daejeon. However, their monthly changes for TOC partially exceeded the standard during the busy farming season at Bonggok 2 Bridge and Gasuwon Bridge. Although the annual average TP was within the standard, the monthly change at Bonggok 2 Bridge partially exceeded the standard. For Dugyecheon, the annual average water quality in 2018 at Umyeon-dong Bridge and Wonjeong Bridge, which are downstream of the Gyeryong public sewage treatment plant, exceeded the local environmental standard in BOD. COD was exceeded, and TP was within the standard. It seemed that the causes of deteriorated water quality downstream of Dugyecheon were discharges of agricultural water from agricultural land and effluent from the Gyeryong public sewage treatment plant. Assuming the pollution load of 100% based at the Mulangil point of the mainstream of Gapcheon, the ratio of BOD load and TOC load were as high as 58% and 47%, respectively. At the basin of Bonggok 2 Bridge and Mulangil, the loads downstream of Dugyecheon including the Gyeryong public sewage treatment plant were as high as 43% for TN and 56% for TP, respectively, indicating that Dugyecheon had a major impact on the water quality at the mainstream of Gapcheon.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.2
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• pp.28-41
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• 2023

The objective of the study was to develop an Urban Windway Forest Creation Planning Technique for the Improvement of the Urban Environment using the case of Daejeon Metropolitan City. Through a spatial analysis of fine dust and heat waves, a basin zone, in which the concentration was relatively serious, was derived, and an area with the potential of cold air flow was selected as the target area for the windway forest development by analyzing the climate and winds in the relevant zone. Extreme fine dust areas included the areas of the Daejeon Industrial Complex Regeneration Business District in Daedeok-gu and Daedeok Techno Valley in Yuseong-gu. Heat wave areas included the areas of Daedeok industrial Complex in Moksang-dong, the Daejeon Industrial Complex Regeneration Business District in Daehwa-dong, and the high-density residential area in Ojeong-dong. As a result of measuring the wind speeds in Daejeon with an Automatic Weather System, the average wind speeds during the day and night were 0.1 to 1.7 m/s,, respectively. So, a plan of for a windway forest that smoothly induces the movement of cold air formed in outer forests at night is required. The fine dust/heat wave intensive management zones of Daejeon Metropolitan City were Daejeoncheon, Yudeungcheon, Gapcheon-Yudeungcheon, and Gapcheon. The windway forest formation plan case involved the old city center of Daejeon Metropolitan City among the four zones, the Gapcheon-Yudeungcheon area, in which the windway formation effect was presumed to be high. The Gapcheon-Yudeungcheon area is a downtown area that benefits from the cold and fresh air generated on Mt. Gyejok and Mt. Wuseong, which are outer forests. Accordingly, the windway forest was planned to spread the cold air to the city center by connecting the cold air generated in the Seosa-myeon forest of Mt. Gyejok and the Namsa-myeon forest of Mt. Wuseong through Gapcheon, Yudeungcheon, and street forests. After selecting the target area for the wind ventilation forest, a climate map and wind formation function evaluation map were prepared for the area, the status of variation wind profiles (night), the status of fine dust generation, and the surface temperature distribution status were grasped in detail. The wind ventilation forest planning concept and detailed target sites by type were identified through this. In addition, a detailed action plan was established according to the direction of creation and setting of the direction of creation for each type of wind ventilation forest.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.585-589
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• 2010

In order to evaluate the performance of a powdered activated carbon (PAC) contactor, two water treatment plants (WTP) were selected as target sites. The result of tracer tests showed that the plug flow portion of a bisymmetry-type contactor (H WTP) was more than 70%. A maze-type contactor (C WTP) also had more than 70% of plug flow portion after intra-basin baffles were installed. According to the operating data of the target WTPs, there was no clear evidence that the addition of PAC contributed to the removal of organics. However, the results of jar tests, conducted with the raw water taken from the H WTP, proved that PAC could remove dissolved organic carbon (DOC) to some extent when the proper velocity gradient was maintained. It was estimated that the production rate, defined as the ratio of the operating flowrate to the design flowrate, of the C and H WTPs was only 27 and 50%, respectively. Because of these lower production rates, the mixing intensity in the contactor was much less than the designed value and, finally, the performance of the PAC contactor was much lower than what was expected.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.4
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• pp.135-144
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• 2010

Many plans of ecologic streams are developed and performed in several regions. In spite of obtaining of instream water is most important problem to composite an ecologic stream, assessment methods for instream water are too various to estimate an optimal result. This study shows practical assessment method which add regional needs such as stream view and necessary water quality level to the traditional method considering water shortage, water quality, ecologic system and necessary flows. It also shows a feasibility of instream water obtaining project in Daejeon city.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.99-111
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• 2012

The purpose of this study is to identify the change of geographical (or geomorphological) location environment of the dwelling site and its cause in Daejon Basin during transition from the Bronze Age to the Proto Three Kingdoms Period. In order to achieve this goal, it was divided into (1) 'comparison of the total number of dwelling sites of a group of remains (or high-density dwelling remains)' and (2) 'comparison of the total number of dwelling sites in certain remains including locations of dwelling of two periods' and location environment was compared to each other in aspects of altitude, gradient, 'distance from the river of water available for use' and 'the difference between the highest altitude and lowest altitude of river bed of water available for use' based on change of period. The results were as follows: 1. looking at a change of individual factors, the altitude was elevated and the gradient was increased. The distance from the river of water available for use was decreased or increased in case of 'small scale river' and it was very little difference or increased in case of 'medium scale river'. The difference between the highest altitude and lowest altitude of river bed of water available for use was increased in case of 'small scale river' and it was increased or decreased in case of 'medium scale river'. If comparing the individual factors to each other, the increase and decrease of altitude, gradient and the difference between the highest altitude and lowest altitude of river bed of water available for use have the similar pattern. Especially, it was shown that the increase of gradient affected the increase of altitude and the difference between the highest altitude and lowest altitude of river bed of water available for use. In addition, it was shown that the increase and decrease of distance from the river of water available for use had the different pattern from those of altitude, gradient and 'the difference between the highest altitude and lowest altitude of river bed of water available for use'. 3. With above results, it was thought that combination of micro landform characteristics (eg. Characteristics of gradient) of low hills distributed within Daejeon Basin and rich aquatic environment surrounding the low hills affected the selection of location of dwelling sites at the time. Especially, it was shown that 'gradient and distance from the river of water available for use' were relatively more important factors for the inhabitants at the time to select the location of dwelling sites compared to 'altitude and difference between the highest altitude and lowest altitude of river bed of water available for use' upon selecting the location of dwelling.

• 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.