• Proceedings of the KSRS Conference
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• v.1
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• pp.239-242
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• 2006

Impervious surface is an important index for the estimation of urbanization and environmental change. In addition, impervious surface has an influence on the parameters of rainfall-runoff model during rainy season. The increase of impervious surface causes peak discharge increasing and fast concentration time in urban area. Accordingly, impervious surface estimation is an important factor of urban rainfall-runoff model development and calibration. In this study, impervious surface estimation is performed by using remote sensing images such as landsat-7 ETM+ and high resolution satellite image and regression tree algorithm based on case study area ? Jungnang-cheon basin in Korea.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.915-922
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• 2008

Impervious surface is an important index for the estimation of urbanization and the assessment of environmental change. In addition, impervious surface influences on short-term rainfall-runoff model during rainy season in hydrology. Recently, the necessity of impervious surface estimation is increased because the effect of impervious surface is increased by rapid urbanization. In this study, impervious surface estimation is performed by using remote sensing image such as Landsat-7 ETM+image with $30m{\times}30m$ spatial resolution and satellite image with $1m{\times}1m$ spatial resolution based on Jungnangcheon basin. A tasseled cap transformation and NDVI(normalized difference vegetation index) transformation are applied to Landsat-7 ETM+ image to collect various predict variables. Moreover, the training data sets are collected by overlaying between Landsat-7 ETM+ image and satellite image, and CART(classification and regression tree) is applied to the training data sets. As a result, impervious surface prediction model is consisted and the impervious surface map is generated for Jungnangcheon basin.

• Korean Journal of Remote Sensing
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• v.23 no.6
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• pp.529-536
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• 2007

As the Imperious surface is an important index for the estimation of urbanization and environmental change, the increase of impervious surfaces causes meteorological and hydrological changes like urban climate change, urban flood discharge increasing, urban flood frequency increasing, and urban flood modelling during the rainy season. In this study, the estimation of impervious surfaces is performed by using Landsat-7 ETM+ image in An-sung area. The construction of sampling data and checking data is used by IKONOS image. It transform to a tasselled cap and NDVI through the reflexibility rate of Landsat ETM+ image and analyze various variables that influence on impervious surface. Finally, the impervious surfaces map is accomplished by regression tree algorithm.

• Journal of Korean Society on Water Environment
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• v.37 no.3
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• pp.157-167
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• 2021

Korea needs to develop a rational system to separate stormwater utility fee from current sewerage fee. In this study, the scenario for calculating stormwater utility fee of Bupyeong-gu was suggested and the results were considered. For this purpose, the application of stormwater utility fee overseas and current domestic system were analyzed. A three step calculating scenario considering suitable domestic situation and impervious surface area was suggested. Water, sewerage usage, and hydrant data were collected. The total amount of water and sewerage fees for land use were calculated. The sewerage fee of Bupyeong-gu for the year 2014 was 21,685,446,578 won. Assuming that 40% of this amount was the cost associated to stormwater, the result showed that the fees for residential area in third step decreased by 0.77% compared to that of the first step. For commercial area, the stormwater utility fee decreased by 36.87%. For industrial area, although the consumption of water was similar to that of commercial area, the stormwater utility fee increased by 8.35%. For green area, the fee increased by 37.46%. This study demonstrated that the calculation of actual stormwater utility fee using impervious surface map and impervious Surface Ratio Estimation Methodology developed in previous studies is feasible.

• Journal of Environmental Impact Assessment
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• v.13 no.5
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• pp.263-276
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• 2004

This research is primarily intended to propose a new concept for aggregate control of impervious coverage using remote sensing and GIS. An empirical study for a case study site was conducted to demonstrate how a standard remote sensing and GIS technology can be used to assist in implementing the aggregate control for impervious coverage as intermediary between decision makers and scientists. Guidelines for a replicable methodology are presented to provide a strong theoretical basis for the standardization of factors involved in the aggregate control; the meaningful definition of land mosaic in terms of pervious areas, classification of pervious intensity, change detection for pervious areas. Detailed visual maps (e.g. estimation of impervious surface allowable) can be generated over large areas quickly and easily to increase the scientific and objective decision-making for the aggregate control. It is anticipated that this research output could be used as a valuable reference to confirm the potential of remote sensing and GIS in the aggregate control for impervious coverage.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.635-645
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• 2014

The changes of rainfall pattern and impervious covers have increased disaster risks in urbanized areas. Impervious covers such as roads and building roofs have been dramatically increased. So, it is falling the ability safety of flood defense equipments to exist. Runoff coefficient means ratio of runoff by whole rainfall which is able to directly contribute at surface runoff during rainfall event. The application of accurate runoff coefficients is very important in sewer pipelines design. This study has been performed to estimate runoff characteristics change which are applicable to the process of sewer pipelines design or various public facilities design. It has used the SHER model, a long-term runoff model, to analyze the impact of a rising impervious covers on runoff coefficient change. It thus analyzed the long-term runoff to analyze rainfall basins extraction. Consequently, it was found that impervious surfaces could be a important factor for urban flood control. We could suggest the application of accurate runoff coefficients in accordance to the land Impervious covers. The average increase rates of runoff coefficients increased 0.011 for 1% increase of impervious covers. By having the application of the results, we could improve plans for facilities design.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.209-217
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• 2016

The rational method is formed area, rainfall intensity and runoff coefficient that is representation of land use or surface type. A runoff coefficient is a range for a each surface conditions. Drainage Sewer Design Guideline revised at 2011 proposes return periods 10~30 year instead of 5~10 year for increasing design flood. Ponce and ASCE refer higher values of runoff coefficient require for higher values of rainfall intensity and return period, therefore runoff coefficient had to be corrected but not. In case of park, land use and surface type are different from Korea and U.S, so impervious area ratio is different. The runoff coefficient for park is estimated considering with impervious area ratio and return period. 1,004's parks in 20 cities are randomly selected for impervious area ratio and runoff coefficient is estimated. And a proportion of 30 year return period runoff coefficient to 10 year return period with rainfall duration is calculated for 69 weather stations. The estimated runoff coefficient is 0.43~0.54 for return period 10~30 year and the difference of region and rainfall duration is not significant.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.181-187
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• 2009

In this study, a runoff hydrograph and runoff volume were calculated by using the kinetic wave theory for small urban watersheds based on the concept of low impact development(LID), and the effective imperviousness was estimated based on these calculations. The degree of sensitivity of the effective imperviousness of small watersheds to the impervious to pervious area ratio, infiltration capability, watershed slope, roughness coefficient and surface storage depth was then analyzed. From this analysis, the following conclusions were obtained: The effective imperviousness and paved area reduction factor decreased as the infiltration capability of pervious area increased. As the slope of watersheds becomes sharper, the effective imperviousness and the paved area reduction factor display an increasing trend. As the roughness coefficient of impervious areas increases, the effective imperviousness and the paved area reduction factor tend to increase. As the storage depth increases, the effective imperviousness and the paved area reduction factor show an upward trend, but the increase is minimal. Under the conditions of this study, it was found that the effective imperviousness is most sensitive to watershed slope, followed by infiltration capability and roughness coefficient, which affect the sensitivity of the effective imperviousness at a similar level, and the storage depth was found to have little influence on the effective imperviousness.

• 한국공간정보시스템학회:학술대회논문집
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• 2007.06a
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• pp.339-342
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• 2007

불투수도는 도시화, 환경변화를 추정하기 위한 중요한 지수로서 도시 기후 변화, 홍수기철 도시 범람의 증가, 홍수 모델링에 영향 등 도시의 홍수 기상학과 수문학적인 변화와 매우 밀접한 관계가 있다. 본 연구에서는 안성지역 일대를 대상으로 하여 Landsat ETM+ 영상을 이용한 불투수도 작성을 시도하였다. 학습자료 및 검수자료 구축은 고해상도 영상인 IKONOS 영상을 이용하였으며, Landsat ETM+ 영상에 대한 위성반사율을 이용하여 tasseled cap과 NDVI로 전환하고 다양한 변수들이 불투수도에 미치는 영향을 분석하였다. 그리고 Regression Tree 알고리즘에 따라 불투수도 추정식을 개발하여 지도화하였다.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.6
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• pp.503-512
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• 2020

Identifying the water circulation status is one of the indispensable processes for watershed management in an urban area. Recently, various water circulation models have been developed to simulate the water circulation, but it takes a lot of time and cost to make a water circulation model that could adapt the characteristics of the watershed. This paper aims to develop a water circulation state estimation model that could easily calculate the status of water circulation in an urban watershed by using multiple linear regression analysis. The study watershed is a watershed in Seoul that applied the impermeable area ratio in 1962 and 2000. And, It was divided into 73 watersheds in order to consider changes in water circulation status according to the urban characteristic factors. The input data of the SHER(Similar Hydrologic Element Response) model, a water circulation model, were used as data for the urban characteristic factors of each watershed. A total of seven factors were considered as urban characteristic factors. Those factors included annual precipitation, watershed area, average land-surface slope, impervious surface ratio, coefficient of saturated permeability, hydraulic gradient of groundwater surface, and length of contact line with downstream block. With significance probabilities (or p-values) of 0.05 and below, all five models showed significant results in estimating the water circulation status such as the surface runoff rate and the evapotranspiration rate. The model that was applied all seven urban characteristics factors, can calculate the most similar results such as the existing water circulation model. The water circulation estimation model developed in this study is not only useful to simply estimate the water circulation status of ungauged watersheds but can also provide data for parameter calibration and validation.