• Water for future
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• v.27 no.4
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• pp.85-94
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• 1994

A Sensitivity analysis on the model parameters involved in the Clark watershed routing method is made to demonstrate the effect of each parameter on the magnitude of 50-year design flood for small urban streams. As for the rainfall parameter the time distribution pattern of design storm was selected. For short duration storms Huff, Yen & Chow and Japanese Central type distributions were selected and the Mononobe distribution of 24-hour design storm was also selected and tested for Clark method application. The effect of SCS runoff curve number for effective rainfall and the methods of subbasin division for time-area curve were also tested. The routing parameter, i.e. the storage constant(K), was found to be the dominating parameter once design storm is selected. A multiple regression formula for K correlated with the drainage area and main channel slope of the basin is proposed for the use in urban stream practice for the determination of design flood by Clark method.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.405-409
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• 2007

Each class in remotely sensed imagery has different spectral and spatial characteristics. Natural features have relatively smaller spatial changes than spectral changes. Meanwhile, urban area in which buildings, roads, and cars are included is inclined to face more changes of spatial variation than spectral one. This study aims to propose the new urban complexity index (UCI) based on the 3D DWT computation of remotely sensed imageries considering these characteristics. And then we analyze relation between index and land cover map. The 3DWUCI values are related to class and the indices of urban area are greater than natural area. The proposed UCI could be used to express effectively the standard of urban complexity over a wide area.

• Journal of Environmental Impact Assessment
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• v.7 no.1
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• pp.63-70
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• 1998

TCM has been used for many environmental impact assessments in Korea. But there was reported that an error was found in area source calculation of original TCM and modified. In this study, TUM(TCM-urban mode) and TRM(TCM-rural mode) were developed for urban and rural area by modification of original TCM. McElroy-Pooler dispersion parameter was used for area and point source in TUM, Pasquill-Gifford parameter was used for area and point source in TRM. And Irwin's vertical wind speed profile exponents were used for TUM and TRM. Then predicted value by TUM, TRM and a value from the same area and point data by CDM2, ISCLT3 were compared. And it was found that predicted value from point source by TUM, TRM was very similar to a value by CDM2, ISCLT3, and predicted value from area source by TRM was similar to a value by CDM2, ISCLT3. But predicted value from area: source by TUM was an half lower than a value by CDM2, ISCLT3.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.766-771
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• 2002

Automatic change detection based on the vector-to-raster comparison is hard especially in high-resolution image. This paper proposes a method to designate roads in high-resolution image in sequential manner using the information from vector map in which Hough transform is used for reliability. By its linearity, the road of urban areas in a vector map can be easily parameterized. Following some pre-processing to remove undesirable objects, we obtain the edge map of raster image. Then the edge map is transformed to a parameter space to find the selected road from vector map. The comparison is done in the parameter space to find the best matching. The set of parameters of a road from vector map is treated as the constraints to do matching. After designating the road, we may overlay it on the raster image for precise monitoring. The results can be used for detection of changes in road object in a semi-automatic fashion.

• Journal of Korea Water Resources Association
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• v.31 no.3
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• pp.243-252
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• 1998

In this study, the new dimensionless values were defined and proposed to determine the parameters of urban runoff models based on the relative sensitivity analysis. Also, the sensitivity characteristics of each parameter were investigate. In order to analyze the parameter sensitivities of each model, total runoff ratio, peak runoff ratio, runoff sensitivity ratio, sensitivity ratio of total runoff, and sensitivity ratio of peak runoff were defined. $$Total\;runoff\;ratio(Q_{TR})\;=\;\frac{Total\;runoff\;of\;corresponding\;step}{Maximum\;total\;runoff}$$$$Peak\;runoff\;ratio(Q_{PR})\;=\;\frac{Peak\;runoff\;of\;corresponding\;step}{Maximum\;peak\;runoff}$$$$Runoff\;sensitivity\;ratio(Q_{SR})\;=\;\frac{Q_{TR}}{Q_{PR}}$$ And for estimation of sensitivity ratios based on the scale of basin area, rainfall distributions and rainfall durations in ILLUDAS & SWMM, the reasonable ranges of parameters were proposed.

• Proceedings of the Korea Water Resources Association Conference
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• 2001.05a
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• pp.359-364
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• 2001

• Journal of Korea Water Resources Association
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• v.36 no.5
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• pp.725-740
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• 2003

Urbanization concerned with concentration of population, activity and expanding the urban changes a natural environmental, and human activity in urban area causes the appearance of a new hydrologic cycle system. This study is carried out the analysis for the characteristics of runoff variation in urban areas with progress of urbanization. To simulate the mechanics of runoffs on small urban watershed, the ILLUDAS model is used in this study. From the analysis of the urban-runoff processes in small urban area with the progress of urbanization, the following conclusions is obtained. It is found in the results of calculated geographical parameter that peak time is quickened by 15∼35 minutes rather than the urbanization before. Also, in the analysis of the peak rate of runoff, the peak flow rise by 60 % than the urbanization before.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.2
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• pp.132-139
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• 1993

TCM has been used for many environmental impact assessments and many case studies in Korea. TCM was applied to urbvan areas and rolling terrains. But original TCM was developed for rural area, and this model could not reflect the characteristcs of these study sites. This paper analyzed the characteristics of TCM, and modified the algorithm of area source, and modified the vertical wind speed profile exponents and diffusion parameter to make it applicable in urban area. In the process of modification, an important error in area source calculation of original TCM program was found. So that was corrected as follows. $$ Before modification $QC = 0.79788456^*(0.5^*GRID)^**BA/(U(IA, IRUN)^*AA^*BA TCM09310$ After modification $QC = 0.79788456^*(500^*GRID)^**BA/(U(IA, IRUN)^*AA*BA) modified$ $$ Then original TCM and modified TCM-urban mode were compared, and it was found that predicted mean value by original TCM was 7 times higher than observed mean value. But mean value by modified TCM-urban mode was very similar to observed value.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.107-111
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• 2008

This paper presented a literature review and investigation analysis results of total 19 present guide book and provisions of maintenance and management system in existing railway bridges to development of urban maglev track structures inspection manual. This research carried out a cooperated research subject 3-1, development a design code and maintenance and management inspection manual for urban maglev track structures, of the Center for Urban Maglev Program. Three types of track structures were includes as a major analytical parameter together with railroad, high speed railroad, subway and light rail transit. Bridges were analyzed a general rules, investigation, evaluation, repair and strengthen method as a key aspect. And rail were analyzed examination and maintenance also. This analysis results show that the track structures evaluation are based on the test and examination results, and repaired or strengthened consideration of deterioration, track irregularity and materials according to provision requirements.

• Journal of Environmental Science International
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• v.19 no.6
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• pp.703-714
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• 2010

In this study, we analyzed the impact of orographic and thermal forcing on the atmospheric flow field over the urban metropolitan areas on urban artificial buildings and future development plan. Several numerical experiments have been undertaken in order to clarify the impacts of the future development plan on urban area by analyzing practical urban ground conditions, we revealed that there were large differences in the meteorological differences in each case. The prognostic meteorological fields over complex areas of Seoul, Korea are generated by the PSU/NCAR mesoscale model(MM5). we carried out a comparative examination on the meteorological fields of topography and land-use that had building information and future development plan. A higher wind speed at daytimes tends to be forecasted when using new topography and land use data that have a high resolution with an appropriate limitation to the mixing height and the nocturnal boundary layer(NCB). During nighttime periods, since radiation cooling development is stronger after development plan, the decreased wind speed is often generated.