• Journal of Environmental Science International
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• v.7 no.4
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• pp.451-460
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• 1998

The objectives of this study Is to evaluate the total runoff yield, peak flow and peak flow travel time depending on the urbanization, return period and rainfall patterns at the downstream of Manchon urban watershed in TaeGu City. SWM(Storm Water Management Model) is used for runog analysis based on 5 different steps of urbanization and 4 different types of Hufrs quartile according to 8 return periods. It is analyzed that the order of total runoff yield according to raiun patterns is Huffs 4, Huffs 2. Huffs 3 and Huffs 1 quartile, that of peak flow magnitude is Huffs 2, Huffs 1, Huffs 4 and Huffs 3 quartile at present development ratio. under the 60, 70, 80 and 90ft of urbanization to the 50% of urbanization by means of the rainfall patterns, the mean Increasing ratio of total runoff yield for each case is 4.55, 11.43, 16.07 and 20.02%, that of peak flow is 5.82, 13.61, 17.15 and 18.83%, the mean decreasing ratio of peak flow travel time Is 0.00, 2.44, 5.07 and 6.26%, the mean increasing ratio of runoff depth Is 4.51, 11.42, 16.02 and 20.05% respectively. the mean increasing ratio of total runoff yield by means of each and 19.71%. Therefore, as the result of this study. it can be used for principal data as to storm sewage treatment and flood damage protection planning in urban small watershed.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.5
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• pp.54-66
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• 2002

A grid-based hydrological model, CELTHYM, capable of estimating base flow and surface runoff using only readily available data, was used to assess hydrologic impacts caused by land use change on Little Eagle Creek (LEC) in Central Indiana. Using time periods when land use data are available, the model was calibrated with two years of observed stream flow data, 1983-1984, and verified by comparison of model predictions with observed stream flow data for 1972-1974 and 1990-1992. Stream flow data were separated into direct runoff and base flow using HYSEP (USGS) to estimate the impacts of urbanization on each hydrologic component. Analysis of the ratio between direct runoff and total runoff from simulation results, and the change in these ratios with land use change, shows that the ratio of direct runoff increases proportionally with increasing urban area. The ratio of direct runoff also varies with annual rainfall, with dry year ratios larger than those for wet years shows that urbanization might be more harmful during dry years than abundant rainfall years in terms of water yield and water quality management.

• Atmosphere
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• v.21 no.3
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• pp.229-241
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• 2011

The continuous urbanizations by a rapid economic growth and a steady increase in population are expected to have a possible impact on meteorology in the downwind region. Long-term (1972~2007) trends of precipitation have been examined in the mid-Korean peninsula for the westerly condition only, along with the sensitivity simulations for a golden day (11 February 2009). During the long-term period, both precipitation amount (PA) and frequency (PF) in the downwind region (Chuncheon, Wonju, Hongcheon) of urban area significantly increased for the westerly and light precipitation ($PA{\leq}1mm\;d^{-1}$) cases, whereas PA and PF in the mountainous region (Daegwallyeong) decreased. The enhancement ratio of PA and PF for the downwind region vs. urban region remarkably increased, which implies a possible urbanization effect on downwind precipitation. In addition, the WRF simulation applied for one golden day demonstrates enhanced updraft and its associated convergence in the downwind area (about 60 km), leading to an increase in the cloud mixing ratio. The sensitivity experiments with the change in surface roughness demonstrates a slight increase in cloud water mixing ratio but a negligible effect on precipitation in the upwind region, whereas those with the change in heat source represents the distinctive convergence and its associated updraft in the downwind region but a decrease in liquid water, which may be attributable to the evaporation of cloud droplet by atmospheric heating induced by an increase in an anthropogenic heat. In spite of limitations in the observation-based analysis and one-day simulation, the current result could provide an evidence of the effect of urbanization on the light precipitation in the downwind region.

• Water for future
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• v.29 no.3
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• pp.207-216
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• 1996

The subject research attempts to evaluate the variations of total runoff volume, peak flow, and travel time depending on the urbanhization, return periods and rainfall patterns under the situations that the preparation of a large residential site at the lowland areas of the downstream of Dongsu stream in Bupyung-Gu, Incheon city is progressed and the area will be eventually fully developed. The ILLUDAS model was used for the runoff analyses based on 3 differend steps of urbanization and 4 different types of Huff's quantile according to rainfall patterns is Huff's 4 quantile, Huff's 2 quantile, Huff's 3 quantile and Huff's 1 quantile. Under the 80 and 90 % of urbanization to the 70% of urbanization, the mean increasing ratio of total runoff volume for each case is 3.5 and 5.5 %, that of peak flow is 4.2 and 8.8%, and the mean decreasing ratio of travel time is 4.4 and 10.1%, respectively. The mean increasing ratio of total runoff volume according to the return periods is 3.0 and 5.4%, that of peak flow is 3.9 and 8.0% under the same conditions of urbanization.

• Journal of Environmental Science International
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• v.19 no.6
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• pp.779-785
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• 2010

To solve a problem of water supply on urban areas, groundwater recharge has to be assessed not only for evaluating the possibility of groundwater development but also for identifying a sustainable aquifer system for water resource development. The assessment of groundwater recharge has been challenged since the land use has been changed constantly. In this study, the groundwater recharge and its ratio were assessed from 1961 to 2007 in Su-yeong-gu, Busan, South Korea by analyzing precipitation, land use, and soil characteristics. For land use analysis, the urbanization change was considered. The land use areas for the residential, agricultural, forest, pasture, bare soil, and water in 1975 occupy 18.6 %, 30.0%, 48.8%, 0.1%, 2.0%, and 0.5% of total area, respectively. The land use ratios were sharply changed from 1980 to 1985; the agricultural area was decreased to 18.3%, and the residential area was increased to 15.0%. From 1995 to 2000, the agricultural area was decreased to 5.5%, and the residential area was increased to 5.4%. The annual averages of precipitation, groundwater recharge, and its ratio were 1509.3 mm, 216.0 mm, and 14.3% respectively. The largest amount of the groundwater recharge showed in 1970 as 408.9 mm, comparing to 2138.1 mm of annual rainfall. Also, the greatest ratio of the groundwater recharge was 19.8% in 1984 with 1492.6 mm of annual rainfall. The lowest amount and ratio of the groundwater recharge were 71.9 mm and 8.0% in 1988, relative to 901.5 mm of annual precipitation. As a result, it is concluded that rainfall has increased, whereas groundwater recharge has decreased between 1961 and 2007.

• Journal of the Korean association of regional geographers
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• v.4 no.2
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• pp.1-14
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• 1998

This research concerns with the urbanization in Pusan City, the largest port city of Korea focus on the changes of traffic volume from 1970 to 1994. These results are as follow: (1) Urbanization of Pusan City has progressed with increasing the efficiencies of streets. At the first, it's ribbon developed along the main artery toward inland. Urbanization is the process of bear a resemblance to characteristics of CBD. It has both expansion and diffusion processed, simultaneously. Urbanization has progressed centered certain nuclei and developed with more varieties are ally and temporally. (2) Traffic volumes according to times which go and return to piers affected to the traffic pattern of the some parts within the city, it is one of characteristics in port city. Variation of traffic volumes according to times much greater at the nearer streets the piers and connected street with it than the rest of the areas within the city. Rivers and mountains affecting to the traffic pattern and play roles of diffusion barriers for urbanization. (3) In the mid-1980, regions which locate along the main arteries had reached to as same level of urbanization as central part of the city. And higher ranked central places within Pusan City developed toward pattern of CBD in the past. It suggests that these central places revoluted to the recreation of CBD function in the past. (4) Urbanization has developed as same as cell differentiation in process, and it encouraged the more greater variation among the regions and become clear the hierarchy of central places within the city.

• KIEAE Journal
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• v.11 no.2
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• pp.75-82
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• 2011

In Korea, the ratio of population in urban areas used to be only 50.1% in 1970, but with the value risen to 90.8% in 2009, urbanization is going on rapidly. Urbanization, which occurs by the rampantly planted buildings, has become major source of raising building density, changing wind direction and reducing wind amount, and such reductions are affecting even inside the building. In each year, among the total energy consumption in Korea, residential portion takes up significant ratio, and specifically the ratio of apartment house is shown to be highest. In order to solve such problem, many studies are being conducted for the improvement of natural ventilation performance. The natural ventilation performance of apartment house are significantly determined by the characteristics of external and internal structure, but in macroscopic perspective, the performance is established fundamentally by the layout characteristics of the main building of the apartment house in preparation for wind conditions. So far researches on raising the thermal comfort through elevation of ventilation performance have been conducted actively, but many of them propose only theoretical concepts deduced through wind path analysis, and do not include any indicator to measure ventilation performance simply only with area data from layout planning stage. Therefore, in this study, gap ratio a wind field measuring indicator was developed, and after the ventilation characteristics by layout types and main building uniformity were identified, the scope of gap ratio efficient for ventilation and that of uniformity were clarified, followed by verification through simulation.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.2
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• pp.1-16
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• 2017

This study was conducted to analyze the urban heat island(UHI) intensity of South Korea by using Moderate Resolution Imaging Spectroradiometer(MODIS) satellite imagery. For this purpose, the metropolitan area was spatially divided according to land cover classification into urban and non-urban land. From the analysis of land surface temperature(LST) in South Korea in the summer of 2009 which was calculated from MODIS satellite imagery it was determined that the highest temperature recorded nationwide was $36.0^{\circ}C$, lowest $16.2^{\circ}C$, and that the mean was $24.3^{\circ}C$, with a standard deviation of $2.4^{\circ}C$. In order to analyze UHI by cities and counties, UHI intensity was defined as the difference in average temperature between urban and non-urban land, and was calculated through RST1 and RST2. The RST1 calculation showed scattered distribution in areas of high UHI intensity, whereas the RST2 calculation showed that areas of high UHI intensity were concentrated around major cities. In order to find an effective method for analyzing UHI by cities and counties, analysis was conducted of the correlation between the urbanization ratio, number of tropical heat nights, and number of heat-wave days. Although UHI intensity derived through RST1 showed barely any correlation, that derived through RST2 showed significant correlation. The RST2 method is deemed as a more suitable analytical method for measuring the UHI of urban land in cities and counties across the country. In cities and counties with an urbanization ratio of < 20%, the rate of increase for UHI intensity in proportion to increases in urbanization ratio, was very high; whereas this rate gradually declined when the urbanization ratio was > 20%. With an increase of $1^{\circ}C$ in RST2 UHI intensity, the number of tropical heat nights and heat wave days was predicted to increase by approximately five and 0.5, respectively. These results can be used for reference when predicting the effects of increased urbanization on UHI intensity.

• Journal of the Korean housing association
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• v.21 no.2
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• pp.101-109
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• 2010

Various environmental problems due to rapid industrialization and urbanization have worsened to such an extent that they threaten the environmental restitution of the globe and become a critical international issue. Korean government has presented the concept of green growth as a new state vision for the next 60 years and is making efforts to solve these environmental problems. Daegu Metropolitan City has faced various environmental problems including overpopulation of the city, traffic pollution, household waste accumulation and the green zone problem because of the increase of urbanization over the last few decades. As such urbanization continues, the quality of residential environments is rapidly deteriorating and the intensive use of the land leads to an increase of building area, raising the temperatures of cities. There have therefore been demands for healthy, pleasant and satisfying residential environments and for the improvement of existing residential environments, and this demand has been fully recognized by society. Nevertheless, current residential complex developments concentrate only on raising the efficiency of land use. In related laws of the past (Daegu Metropolitan City, Urban Planning Municipal Ordinance as of October 10, 2003) an attempt was made to impose a standard to segmentalize the building-to-land ratio, floor area ratio and regulations of number of floors vertically. However, these laws have now been abolished and the regulations are being eased. The purpose of this study was to analyze the characteristics of the floating wind before and after the vertical segmentation of residential areas (Daegu Metropolitan City, Urban Planning Municipal Ordinance as of October 10, 2003) by using KLAM_21, a model that enables analysis and prediction of the flow and generation of cold wind. The purpose is also to present a plan to improve the quality of residential areas when developing a building lot and redeveloping housing areas.

• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.166-177
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• 2010

This study is to identify potential factors to impact on appearance of wildbirds which live in the core forest around urban area in Gangdong-gu, Seoul. As a result of analysis of, studies on biotope showed most of urbanization biotope was biotope of residential areas with high green coverage and biotope of residential and business areas with low green coverage while most of biotope of green and openspace was core green biotope. The research area was divided into several blocks based on biotope types in the urbanization areas excluding green and openspace. As a result of research on wildbirds, total 51 species 3,419 individuals appeared in spring and total 35 species 4,213 individuals appeared in winter. 24 wild bird species were selected as subjects of this study among 31 species seen in urbanization areas, since urban birds, rapacious birds, waterside birds were excluded from the study for the proper consideration. Then this study looked at how many species and individuals of the subjects were observed at each research block in urbanization areas during spring and winter separately. Landuse structure and green structure in each block were examined to see whether these structures affect the number of wild birds observed in urbanization areas of Gangdong-gu. Furthermore, the distance between these blocks and green was assessed. While studying the potential links between the landuse structure and the number of wild birds observed in urbanization areas of Gangdong-gu, block area, green coverage, and building-to-land ratio were believed to affect the number of types and species of wild birds in the research area. In terms of correlation analysis of whether green structure affected the number of wild birds observed in urbanization areas of Gangdong-gu, crown volume of layers, the average green patch area, the average height of canopy layer were found to have an impact not only on the number of types but also species of wild birds in the research area.