• Journal of Wetlands Research
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• v.18 no.2
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• pp.194-200
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• 2016

The impervious surface rate increased by urbanization causes various problems on the environment such as water cycle distortion, heat island effect, and non-point pollutant discharges. The Low Impact Development (LID) techniques are significantly considered as an important tool for stormwater management in urban areas and development projects. The main mechanisms of LID technologies are hydrological and environmental pollution reduction among soils, media, microorganisms, and plants. Especially, the media provides important functions on permeability and retention rate of stormwater runoff in LID facilities. Therefore, this research was performed to assess the pollutant removal efficiency for different types of media such as zeolite, wood chip, bottom ash, and bio-ceramic. All media show high pollutant removal efficiency of more than 60% for particulate materials and heavy metals. Double layered media is more effective in reducing heavy metals by providing diverse sizes of micro-pores and macro-pores compared to the single layered media. The results recommend the use of different sizes of media application is more cost-effective in LID than a single size of media. Furthermore, soluble proportion of total heavy metal in the stormwater is an important component in proper media selection and arrangement.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1077-1089
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• 2022

With the construction of Seoul National University (SNU), the Mt. Gwanak watershed has undergone some urbanization. As with other campus catchments, data related to the water cycle is extremely limited. Therefore, this study began by collecting hydrological and meteorological data using Atmos-41, a complex meteorological observation instrument. The observation results of Atmos-41 were validated by analyzing the statistical characteristics and confidence intervals based on the monthly variability of data from the Korea Meteorological Administration. Results of the previous research were used to validate the simulated surface runoff and infiltration using the Storm Water Management Model (SWMM). The potential evapotranspiration (PET) simulated by the SWMM was rectified by comparing it to the Atmos-41 observation data. Multiple regression analysis was employed to adjust for the fluctuations in precipitation, relative humidity, and wind speed because the calculated SWMM PET tends to be underestimated during periods of low temperatures. R² increased from 0.54 to 0.80 when compared to the Atmos-41 PET. The rate of change in the water cycle as a consequence of the SNU's construction resulted in a 15.7% increase in surface runoff, a 14.2% decrease in infiltration rate, and a 1.6% decrease in evaporation.

• Journal of the Korean Geographical Society
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• v.30 no.3
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• pp.242-254
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• 1995

The Hadano Basin is located at a distance of about 70kms and 60kms from Tokyo and Yokohama and lies in the south-west part of the Kanto region in Japan. The basin area, which correspoends to the catchment of the Kaname River, is about areal size of 60.7$\textrm{km}^2$ and extends about length of 8kms in E-W direction and about width of 5kms in N-S direction (Fig.1). The Hadano basin is filled with thick pile of the alluvum from deposits composed of volcanic materials, mostly came from the Hakone Volcano and overlain by Fuji Volcanic ashes. Fluvial deposits form the good aquifer, therefore water resources of Handano City has been largely depending upon the eroundwater. Urbanization and industrialization of the basin has been rapid in the last thirty years, after activation of "Factory Attraction Policy of Hadano City" in 1956. Growth in population and number of factory due to urbanization changed the land-use pattern of the basin rapidly and increased the water demands. Therefore, Hadano City exploited a new source of water supply, and have introduced the prefectureal waterworks since 1976. On the other hand, the rapid urbanization has brought about the pollution of streams in the basin by domestic sewage and industrial waste water. Diffusion rate of sewerage systems in Hadano City is 38% in 1993. In ordcr to examine the impact of anthropogenic factors on river environments, the author took up the change of land-use and diffusion area of sewerage as parameters, and performed field surveys on water discharge and quality. The survey has been made at upstream and downstream of the main stream regularly per month, to get informati ons about the variation of discharge and water quality aiong the stream and its diurnal fluctuation. Annual variation has been analyzed based the data from Hadano City Office. The results are summarized as follows. 1. Stream discharge has been increasing by urbanization (Fig.3). Water quality (C $l^{-10}$ , N $H^{+}$$_{ 4}$-N, BOD) has been improving gradually after the application of sewerage service, yet water pollution load at the lower station has increased than that at the upper one because of the larger anthropogenic discharge volumes (Fig.4). 2. Corrclation coefficient of discharges between upper and lower was 0.81-0.92. Pollutant loads of the R. Kamame after the confluence with R. Kuzuha grew up by 2.4-3.7 times as compared with its upper reaches, and it increased to 3.7-6.9 times after the confluence with the R. Muro (Fig.5). 3. The changes of water quality along the stream can be divided into two groups (Fig.6a). First: water quality of the R. Kaname and R. Shijuhachisse is becoming worse towards the lower reaches because the water from branches are polluted. Second: water quality are improved in the lower where spring and small branch streams supply clear water, for example R. Mizunashi, R. Muro and R. Kuzuha. 4. Measured discharge at the upper station in the R. Shijuhachisse is 0.153㎥/sec, and about 55% of this is recharged until it reaches to the lower point. The R. Mizunashi has a discharge of 1.155㎥/sec at the upper point, is recharged 0.24㎥/sec until the midstream and groundwater spring 0.2㎥/sec at the lower reaches. R. Kuzuha recharged all the mountain runoff (0.2㎥/sec) at the upper reaches. The R. Muro is supplied by many springs and the estimated discharge of spring was 0.47㎥/sec (Fig.6b). 5. Diurmal variations in discharge and water quality are influenced clearly by domestic and industrial waste waters (Fig.7, 8).ed clearly by domestic and industrial waste waters (Fig.7, 8).

• Atmosphere
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• v.17 no.2
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• pp.171-183
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• 2007

Trends of daily maximum and minimum temperatures in major cities of South Korea (Seoul, Busan, Incheon, Daegu, and Ulsan) during the past 40 years (1961-2000) were investigated. Temperature records for the Chupungryeong station were compared with those of the large cities because of the rural environment of the station. There were distinct warming trends at all stations, although the warming rates depend on each station's local climate and environment. The warming rates in Korea are much greater than the global warming trends, by a factor of 3 to 4. The most increasing rate in daily maximum temperature was at Busan with $0.43^{\circ}C$ per decade, the most increasing rate in daily minimum temperature was at Daegu with $0.44^{\circ}C$ per decade. In general, the warming trends of the cities were most pronounced in winter season with an increasing rate of $0.5^{\circ}C$/decade at least. Diurnal temperature range shows positive or negative trends according to the regional climate and environmental change. The frequency distribution of the daily temperatures for the past 40 years at Seoul and Chupungryeong shows that there have been reductions in cold day frequencies at both stations. The results imply that the impacts on human health might be positive in winter and adverse in summer if the regional warming scenario by the current regional climate model reflects future climate change in Korea.

• Journal of Environmental Science International
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• v.18 no.5
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• pp.527-538
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• 2009

A village grove is the one fostered and protected for a district's traditional life near the vicinity of a ruderal village. This research is done to grasp potential natural vegetation, to use a basis data needed for its management and preservation as well as restoration project by examining the vegetation and flora targeting a village grove of the southern district of Gyeonggi-do which has been seriously damaged subsequent to a rapidly progressing city development. According to the survey, there appeared an outgrowth flora of Pteridophyta consisting of 69 families, 136 genera, 20 varieties, 3 forms, 170 species-totalling to 193 taxa. Urbanization index was revealed to 4.55% and naturalization rate 6.74%. In life-cycle pattern, perennials were found to show the highest distribution rate; in infiltration-multiplication strategies, human wave tactics type was found to be the highest 51%, consisting of 98 species, and naturalization rate also was revealed to be 6.74%. The vegetation unit was divided into a total of 11 patterns, such as a community of Pinus densiflora community, Pinus densiflora-Pinus rigida community, Pinus densiflora-Castanea crenata community, Pinus rigida community, Pinus rigida-Castanea crenata community, Pinus rigida-Quercus acutissima community, Castanea crenata community, Castanea crenata-Quercus acutissima community, Quercus acutissima community, Quercus acutissima-Robinia pseudo-acacia community and Robinia pseudo-acacia community. Quercus acutissima community is of a community type dominated by Quercus acutissima, in place of Pinus densiflora community selected by natural succession.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.1-11
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• 2016

Currently, urban green space is disappearing due to urbanization, industrialization and various environmental problems including the disruption of the ecology in urban areas. To solve such problems and increase urban green area, roof greening has been suggested as an alternative. Through observing the responses of three plant species (Mukdenia rossii, Dianthus chinensis, and Pachysandra terminalis) plantrd on the soil mixed with Geohumus, this study investigated the effect of Gehumus on soil water content and plant survival. Soil water content of the rooftop soils has been increased when mixed with Geohumus. The responses were proportional to the amount of Geohumus in the mixture. Geohumus exerted a stronger influence on raising soil moisture content for soil A which had lower water-holding capacity. The stress responses of the plants varied in relation to the amount of Geohumus and soil moisture content. The stress response was lowest for Dianthus chinensis and increased in the order of Mukdenia rossii and Pachysandra terminalis. With the highest plant stress, Pachysandra terminalis showed the lowest survival rate among the three species. Without irrigation, the plants survived only for six weeks on green roofs. The survival rate differed depending on the amount of Geohumus mixed. The results of the experiment showed, with some exceptions, that Geohumus helped to improve soil water content, reduce plant stress, and extend plant survival period.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.4
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• pp.611-634
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• 2017

In rapid urbanization, demand for utility tunnel increases more, and tunnel boring machine (TBM) has been used widely. Prediction of TBM penetration rate is important for proper estimation of construction period and cost. Although there are several methods, such as NTNU model and CSM model that require many input parameters, fundamental understanding on correlations between rock properties and TBM penetration rate is critical. In this study, we explored the brittleness indices of hard rocks according to various definitions, and the correlations between the brittleness indices and the TBM penentration rates.

• Journal of Environmental Science International
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• v.13 no.12
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• pp.1023-1032
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• 2004

Rapid progress in urbanization has resulted in a change of the micro climate, especially in the urban area. In order to investigate the phenomenon of the heat island in the residential micro climate, a field survey was carried out by 4 sets of the residential type in Jeonju under typical winter synoptic condition. As analytic methode, it is used the comparison on the relation of the Land-to-Coverage Rate to Heat Island and Oxygen Concentration. And as a key question it is asked how stable characteristics of the micro climate will result from the survey of the Heat Island and the Oxygen Concentration, used as indicator. To ensure the trustworthy result of research, it is calculated the critical influence of the wind velocity and the Land-to-Covearage Rate. As a result of comparative analysis, it could be confirmed that the local temperatures in all sets of the residential type were higher than the average temperature in Jeonju. But the housing type A 'exclusive use for housing zone' has relativly the most stable and best living condition. On the contrary the residential type B and D has the worst toward the oxygen concentration in the time zone 9-12 a.m., which didn't reach the minimum of the oxygen concentration $20.5{\%}.$ It means that the higer the development and population density is, the worse is the situation of the Quality of Life in the residential types in accordance with the heat island and oxygon con­centration.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.6
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• pp.857-870
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• 2017

The use of shield TBM is gradually increasing due to the urbanization of social infrastructures. Reliable estimation of advance rate is very important for accurate construction period and cost. For this purpose, it is required to develop the prediction model of advance rate that can consider the ground properties reasonably. Based on the database collected from field, statistical prediction procedure for field penetration index (FPI) was modularized in this study to calculate penetration rate of shield TBM. As output parameter, FPI was selected and various systems were included in this module such as, procedure of eliminating abnormal dataset, preprocessing of dataset and ridge regression with best subset selection. And it was finally validated by using field dataset.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.237-246
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• 2015

Heavy metal pollution in soil, such as lead contamination, has become an area of interest in Korea because of urbanization and atmospheric deposition from neighboring countries. Therefore, in this research, eco-physiological responses such as chlorophyll contents, antioxidant enzyme activity, photosynthetic rate, biomass and phytoaccumulation abilities were investigated for 4 commonly used native roadside tree species to suggest suitable tree species to cope with lead contamination. The target species, Ginkgo biloba, Prunus yedoensis, Zelkova serrata and Chionanthus retusus showed lead toxicity by significant changes of chlorophyll contents and antioxidant enzyme activities on treatments over 200 mg Pb/kg. However, biomass and photosynthetic rates only showed significant responses of plants in the highest level (5,000 mg/kg) treatment. Especially, G. biloba did not show any significant changes of antioxidant enzyme activity, photosynthetic rate, and biomass even in the highest level treatment. In low level - environmentally realistic treatments, G. biloba and P. yedoensis showed the highest phytoaccumulation rate of lead from soil. Selecting and planting species like G. biloba which have good phytoaccumulation abilities and resistance to lead contamination by further research will be required to deal with emerging lead contamination.