• 환경영향평가
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• 제23권1호
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• pp.39-50
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• 2014

In recent years, the frequency and scale of the natural disasters are growing rapidly due to the global climate change. In case of the urban flooding, high-density of population and infrastructure has caused the more intensive damages. In this study, we analyzed the spatial characteristics of urban flooding damage factors using GWR(Geographically Weighted Regression) for effective disaster prevention and then, classified the causes of the flood damage by spatial characteristics. The damage factors applied consists of natural variables such as the poor drainage area, the distance from the river, elevation and slope, and anthropogenic variables such as the impervious surface area, urbanized area, and infrastructure area, which are selected by literature review. This study carried out the comparative analysis between OLS(Ordinary Least Square) and GWR model for identifying spatial non-stationarity and spatial autocorrelation, and in the results, GWR model has higher explanation power than OLS model. As a result, it appears that there are some differences between each of the flood damage areas depending on the variables. We conclude that the establishment of disaster prevention plan for urban flooding area should reflect the spatial characteristics of the damaged areas. This study provides an improved understandings of the causes of urban flood damages, which can be diverse according to their own spatial characteristics.

• 한국물환경학회지
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• 제27권4호
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• pp.391-396
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• 2011

Recently it revealed that urban runoff was one of the major source that contaminates the river, lake and estuary because it contains toxic compounds such as heavy metals and Poly Aromatic Hydrocarbons (PAHs) as well as suspended solids, organic compounds and nutrients. The engineered polymetric media in this research were developed for reducing pollutants in urban runoff and would be used to be charged in the storm water treatment equipment. The engineered media that were composed of the polypropylene was foamed to have the buoyancy and then shattered by mechanical for the efficient filtration. In this study, Spherical Expanded Polypropylene Media (SEPM), Crushed Polypropylene Media (CPM), Large Crushed Expanded Polypropylene Media (LCEPM), Small Crushed Expanded Polypropylene Media (SCEPM) were made from polypropylene. Surface characteristics of the developed media were determined by scanning electron microscopy analyses. Also, removal efficiencies of SS, $COD_{Cr}$ in the artificial road runoff and the bed headloss by media and particle pollutants captured by media were examined. Results on the surface characteristics of media indicated that SCEPM had the largest specific surface area, $0.80m^2/g$, the lowest specific gravity, 0.091, and the biggest porosity, 0.63, because of crushing the media at the process of manufacturing. And the SCEPM's removal efficiencies of TSS and $COD_{Cr}$ in the artificial road runoff were 92.9% and 83.6%, respectively and the headloss of SCEPM was the least of them.

• 한국측량학회지
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• 제39권2호
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• pp.113-122
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• 2021

Urban expansion, particularly converting sub-urban areas to residential and commercial land use in metropolitan areas, has been considered as a significant signal of regional economic development. However, this results in urban climate change. One of the key impacts of rapid urbanization on the environment is the effect of UHI (Urban Heat Island). Understanding the effects of urban land cover change on UHI is crucial for improving the ecology and sustainability of cities. This research reports an application of remote sensing data, GIS (Geographic Information Systems) for assessing effects of urban land cover change on the LST (Land Surface Temperature) and heat budget components in Ho Chi Minh City, where is one of the fastest urbanizing region of Vietnam. The change of urban land cover component and LST in the city was derived by using multi-temporal Landsat data for the period of 1998 - 2020. The analysis showed that, from 1998 to 2020 the city had been drastically urbanized into multiple directions, with the urban areas increasing from approximately 125.281 km² in 1998 to 162.6 km² in 2007, and 267.2 km² in 2020, respectively. The results of retrieved LST revealed the radiant temperature for 1998 ranging from 20.2℃ to 31.2℃, while that for 2020 remarkably higher ranging from 22.1℃ to 42.3℃. The results also revealed that given the same percentage of urban land cover components, vegetation area is more effective to reduce the value of LST, meanwhile the impervious surface is the most effective factor to increase the value of the LST.

• 환경영향평가
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• 제24권1호
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• pp.16-34
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• 2015

불투수면(IC)이란 빗물 등의 강수가 토양 속으로 침투할 수 없는 포장 지역이라 정의할 수 있으며, 일반적으로 도시화 과정에서 형성되는 불투수면은 주로 도로(Drive way), 인도(Sidewalk), 주차장(Parking lot), 건물의 지붕(Roof) 등의 형태로 나타난다. 불투수면의 증가는 유출계수를 증가시켜 강수의 침투량 및 지하수 수위를 감소시킨다. 이로 인해 홍수기에 직접 유출량과 홍수피해를 증가시키고, 갈수기에는 하천의 건천화를 유발하여 수생태계를 악화시킨다. 미국 환경부에서는 불투수면을 저감하기 위한 주요정책으로 LID(Low Impact Development) 또는 GI(Green Infrastructure)의 도입을 제시하고 있다. 본 연구에서는 도시 유역의 강우-유출 및 수질 해석을 위해 SWMM모형을 구축하고, 도시 유역의 대표적인 토지이용 유형에서 불투수면 영향 저감을 위한 다양한 LID 기법을 적용하고 그 효과를 평가하였다. 모형의 보정기간은 2009년 7월 17일, 검정기간은 2009년 8월 11일이며, 강우유출발생시 측정한 실측 데이터를 사용하여 검 보정을 하였다. 아파트, 학교, 도로, 공원 등으로 구성된 복합용지에 투수성 포장(Pervious cover)과 옥상녹화(Green roof)기법을 단계별로 적용하고 유출량 및 오염부하 저감에 미치는 영향을 모의한 결과, 유역 내 불투수면이 투수면으로 전환되는 비율이 증가함에 따라 강우시 발생하는 유출량과 오염물질 부하량의 저감 효과가 큰 것으로 나타났다. 특히, 건물 옥상 녹화 및 주차장과 도로에 투수성 포장을 적용한 경우, 총 유출량은 15~61 %의 저감효과를 보였으며, 오염부하량에 대해서는 TSS 22~72 %, BOD 23~71 %, COD 22~71 %, TN 15~79 %, TP 9~64 %의 저감효율을 나타냈다.

• 한국환경복원기술학회지
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• 제18권3호
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• pp.65-77
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• 2015

The urban park has important functions as a habitat for wildlife as well as open space of rest and community for people. This study was carried out to find what factors of structure and vegetation of urban parks could affect forest bird species diversity in Cheonan city. The study surveyed bird and vegetation species in 26 urban parks, Cheonan city. A correlation analysis and multiple linear regressions were performed to test whether habitat structure and vegetation were the major correlate with species diversity. The results showed the Dujeong park was the most high bird species diversity (H' = 2.13), and the Dujeong-8 park (H' = 2.02) and the Cheongsa park (H' = 1.73) were considerably higher than the other urban parks. The variables that were strongly correlated with bird species diversity were park area, number of subtree species, canopy of shrub, number of shrub species, shape index, canopy of subtree, canopy of tree, and impervious surface ratio. The regression of bird species diversity against the environmental variables showed that 3 variables of park area, canopy of subtree, and canopy of tree were included in the best model. Model variable selection was broadly similar for the 5 optimal models. It means park area and multi-layer vegetation were the most consistent and significant predictor of bird species diversity, because urban parks were isolated by built-up areas. Especially the subtree coverage that provides shelter and food for forest birds was an important variable. Therefore, to make parks circular-shaped and abundant multi-layer vegetation, which could be a buffer to external disturbances and improve the quality of habitats, may be used to enhance species diversity in creation and management of urban parks.

• 한국지리정보학회지
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• 제13권1호
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• pp.142-154
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• 2010

본 연구는 경상남도 창원시를 대상으로 다양한 도시의 공간적 특성이 지표온도에 미치는 영향성을 분석하고, 도시지역의 유형에 따른 열환경 특성을 파악하고자 한다. 이를 위해 Landsat 5 TM 영상에서 지표온도, NDBI(Normalized Difference Built-up Index), NDVI(Normalized Difference Vegetation Index) 등을 추출하였으며, 고해상도($10cm{\times}10cm$) 칼라항공사진을 토대로 토지이용 및 토지피복 형태를 분류하였다. 공간통계분석의 기본단위는 $500m{\times}500m$의 Vector Grid로 구축하여 각각의 공간특성 인자별 주제도를 작성하였다. 열환경과 공간특성의 관계성을 평가한 결과, 지표온도와 NDBI의 상관계수가 0.929로 가장 높게 나타났으며, 불투수지역의 비율과도 0.857의 높은 상관성을 가지는 것으로 분석되었다. 다음으로 도시지역의 유형을 주거중심, 공업중심, 녹지중심, 혼합의 4개 지역으로 군집 분류하여 유형별 지표온도를 분석한 결과, 공업중심지역의 지표온도가 $21.10^{\circ}C$로 가장 높았고, 녹지중심지역이 $18.85^{\circ}C$로 가장 낮게 평가되었다. 이상의 연구결과는 도시 지역의 공간적 특성이 열환경에 미치는 영향성을 규명하였으며, 향후 열환경 개선을 위한 토지이용계획과 개발밀도 규제 등에 활용 가능할 것으로 판단된다.

• KIEAE Journal
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• 제6권3호
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• pp.27-34
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• 2006

The recent emphasis on ecological urban development has led to the need to maintain a hydrologic cycle in urban areas. As such, this study proposes decentralized rainwater management, a concept of onsite rainwater management that involves the utilization, infiltration, detention, and retention of rainwater. The main objective of this research is to estimate the proportion of decentralized rainwater management that is needed. From the research that was conducted in this study, it was found that the total runoff quantity increases by 10-20% after district lands are developed, when the probable rate of precipitation every 10 years is within this range. Thus, the runoff rate can be reduced by 10~20% of the total runoff quantity through decentralization. On the other hand, in the scale of housing complex development, the total runoff quantity increases by as much as 10~40% due to the changes in the rate of the impervious surface area. If 10-40% of the total runoff quantity was processed through decentralized rainwater management, the rate of infiltration, detention, retention, and runoff in precipitation prior to development could be recovered.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.744-744
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• 2012

불투수층은 자연적인 침투를 허용하지 않는 인위적인 토지피복상태로 도시화율 추정 및 유역의 환경변화 정도를 분석하기 위한 척도로 사용되어 왔다. 특히, 수문학적 관점에서 불투수층은 단기 유출현상에 큰 영향을 끼치는 요소로 불투수율이 증가할수록 침투량이 감소하여 첨두유출량은 증가하고 도달시간은 짧아진다. 최근에는 급속한 도시화로 인해 불투수층의 영향이 더욱 커짐에 따라 불투수율의 추정에 대한 필요성이 증가하고 있다. 현재까지 위성영상을 이용한 불투수층의 추정은 고해상도 영상을 이용하여 피복분류를 수행하였다. 즉, 분류된 토지피복에 근거하여 불투수율을 산술적으로 계산하거나 분광혼합기법 및 회귀 트리기법 등 다양한 방법에 적용되어 왔다. 본 연구에서는 Sub-pixel 분류기법을 위성영상에 적용하여 섬강유역의 불투수율을 추정하고자 한다. Sub-pixel 분류는 기존 분류기법들이 다양한 토지피복이 혼합된 화소에 대해서도 가장 비중이 높은 토지피복 하나로 분류하던 것을 개선한 방법으로 fuzzy 이론을 적용하여 최소 20% 이상의 비율을 점유하는 항목 모두를 구분하여 분류하는 기법이다. 이를 위해 섬강유역의 Landsat TM 영상을 수집하고 환경부의 토지피복도와 지질도를 참조하여 트레이닝 자료를 수집하였다. 또한 결과에 영향을 미칠 수 있는 구름은 전처리를 통하여 제거하고 수집된 트레이닝 자료에 Sub-pixel 분류기법을 적용하여 섬강유역의 불투수율을 공간분포도로 작성하였다.

• 한국농공학회논문집
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• 제53권6호
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• pp.75-84
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• 2011

The objective of this study is to evaluate the hydrologic impacts of climate and land use changes in a rural small watershed. HadCM3 (Hadley Centre Coupled Model, ver.3) A2 scenario and LARS-WG (Long Ashton Research Station - Weather Generator) were used to generate future climatic data. Future land use data were also generated by the CA-Markov (Cellular Automata-Markov) method. The Soil and Water Assessment Tool (SWAT) model was used to evaluate hydrologic impacts. The SWAT model was calibrated and validated with stream flow measured at the Baran watershed in Korea. The SWAT model simulation results agreed well with observed values during the calibration and validation periods. In this study, hydrologic impacts were analyzed according to three scenarios: future climate change (Scenario I), future land use change (Scenario II), and both future climate and land use changes (Scenario III). For Scenario I, the comparison results between a 30-year baseline period (1997~2004) and a future 30-year period (2011~2040) indicated that the total runoff, surface runoff, lateral subsurface runoff, groundwater discharge, and evapotranspiration increased as precipitation and temperature for the future 30-year period increased. The monthly variation analysis results showed that the monthly runoff for all months except September increased compared to the baseline period. For Scenario II, both the total and surface runoff increased as the built-up area, including the impervious surface, increased, while the groundwater discharge and evapotranspiration decreased. The monthly variation analysis results indicated that the total runoff increased in the summer season, when the precipitation was concentrated. In Scenario III, the results showed a similar trend to that of Scenario II. The monthly runoff for all months except October increased compared to the baseline period.

• 한국물환경학회지
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• 제34권3호
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• pp.293-300
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• 2018

Ihe purpose of this study is to evaluate the effects the storage type of permeable concrete block paving (ST-PCBP) have on runoff reduction and infiltration increasement at Andong Maskdance Festival Square. This was accomplished using the NRCS-curve number method over the last 10 years. Two different scenarios were developed in this study for low impact development (LID) design. For the $1^{st}$ scenario, the walking path and parking lot were install using the ST-PCBP and runoff from the inline skating rink ($3,808m^2$) and lawn ($11,191m^2$) were routed to the ST-PCBP, but the rooftop runoff flowed into the storm water drainage system. For the $2^{nd}$ scenario, one of the non-structural BMPs, disconnected impervious surface (DIS), was applied so additional runoff from rooftop would enter the ST-PCBP. It was determined that ST-PCBP could significantly reduce surface runoff from the study area and increase infiltration with 71% and 88% of surface runoff reduction and 151% and 215% of infiltration increasement for scenarios 1 and 2, respectively. The effect of LID in the $2^{nd}$ scenario was better than the $1^{st}$ scenario, therefore DIS in conjunction with ST-PCBP could be a more cost-effective LID application.