• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1187-1190
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• 2006

최근 급속한 도시화에 따른 토지이용 증가와 토지이용 효율성의 증대는 불투수 표면의 확대, 유역의 조도계수 감소와 함께 유입시간의 단축, 수로망 정비에 의한 첨두유량의 증가, 도달시간의 감소를 발생시켜, 수로의 통수능 증가와 저류량의 급격한 감소 등 전반적인 수문현상의 변화를 가져와 도시 하천유역에 홍수 피해를 빈번히 발생시키고 있을 뿐만 아니라 근시안적인 난개발로 인해 하천 생태계가 파괴되는 등 하천 오염이 갈수록 심각해지고 있다. 근년에 들어 이런 문제 해결을 위해 하천정비시 자연형 개념을 도입하여 공사가 시행되고 있으며 본 연구의 대상하천으로 선정된 온천천이 부산의 그 대표적인 예라 하겠다. 본 연구에서는 자연형 하천의 복원에 따른 홍수위 변화와 피해 분석을 위해 먼저 온천천이 자연형 하천으로 복원되기 이전의 하도 단면과 복원 후 변화된 하도 단면으로 분류하였으며, GIS 기법을 이용해 공간 지형자료를 정량적으로 산출하였다. 하천 복원에 따른 특성 분석을 위하여 부산지방기상청으로부터 수집된 강우자료를 이용하여 확률강우량을 산정한 후 빈도별 홍수량을 산정하였다. 산정된 빈도별 홍수량을 HEC-RAS(River Analysis System) 모형에 적용하여 복원 전.후의 홍수위를 모의한 결과 온천천의 친수공간을 대표하는 주요지점에 대해 안전하다고 판단되었으나 온천천이 시민들의 친수공간으로 이용되고 있는 자연형 하천임을 고려할 때 돌발홍수에 대한 홍수예경보가 반드시 필요하다고 본다.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1565-1569
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• 2009

과거의 치수기능 위주의 하천정비에서 벗어나 최근에는 자연 친화적인 하천 복원에 대한 관심의 증가로 많은 지자체에서는 자연형 하천정비사업을 시행하고 있다. 이러한 자연형 하천정비 사업으로 인하여 하천의 조도계수가 변화하지만 하천설계기준에서 제안하여 현재 사용되고 있는 조도계수의 경우 그 범위와 구분이 명확하지 않아서 자연형 하천정비사업 후에도 조도계수 변화에 대한 고려 없이 홍수위 및 홍수범람지역을 산정하고 있다. 따라서 본 연구에서는 1차원 홍수범람 모형인 HEC-GeoRAS를 이용하여 홍제천 유역을 대상으로 극한홍수시 조도계수 변화에 따른 홍수범람지역 변화를 분석하였다. 조도계수는 하천설계기준에서 제안한 인공하천의 조도계수 값 중 최소 값인 0.014부터 자연하천에서의 최대 값인 0.05까지 변화시켜 그에 따른 홍수범람지역의 면적을 산정하였다. 분석결과 조도계수가 증가함에 따라서 침수면적이 증가되었으며 조도계수 0.02$\sim$0.03구간에서 침수면적의 증가율이 9.69%로 가장 크게 나타났다. 또한 홍제천의 자연형 하천 정비사업 후 극한홍수시 침수면적이 약 11.91% 증가하였다. 따라서 자연형 하천정비 사업시 반드시 조도계수 변화를 고려하여 홍수위 및 침수면적을 산정하여야 할 것이며 홍수위 및 침수면적 증가에 따른 영향을 고려하여 설계에 반영해야 할 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1230-1234
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• 2009

산지하천 유역에서 돌발적으로 발생하는 홍수는 얼마나 신속히 예측할 수 있는 가에 따라 피해 정도가 크게 변화한다. 현재 국내에서는 도시하천과 일반 유역 등을 대상으로 하는 홍수 유출 해석이 대부분이며, 산지하천에 대해 특화된 홍수 유출 해석 시스템은 개발된 경험이 거의 없다. 우리나라에서는 60%이상을 차지하는 산지하천유역의 홍수유출해석을 수행할 때 외국의 지형에 맞게 개발된 여러 가지 경험식을 사용하여 집중시간을 산정해왔다. 평지가 많은 외국의 경험식으로 집중시간을 산정할 경우 산지하천의 지형적 특성을 충분히 고려하지 못하게 되어 실제 집중시간과 산정된 집중시간과의 차이가 크게 발생할 수 있다. 산지하천 유역에서 홍수유출해석에 필요한 집중시간 산정을 정확하게 하기 위하여 수문지형학적 기법으로 유역을 분석하고 지형적 특성을 포함하는 집중시간 산정기법을 검토하였다. 집중시간 산정기법은 GIS를 기반으로 유역 내 경사도와 경사향을 분석하고 유역의 최원점에서의 흐름경로를 설정하여 집중시간을 산정하는 방법이다. 개발된 모형을 평창강유역에 적용한 결과 유역 내 호우가 발생할 경우 집중시간을 단시간 내에 산정할 수 있어 신지하천 유역의 홍수유출을 해석하는데 도움이 된다는 것을 발견하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.655-662
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• 2005

The objective of this thesis is to develop a prediction system of potential landslide sites to apply to the prevention of landslide disaster which occurred during the heavy rainfall in the rainy season. The system was developed by combining a modified slope stability analysis model and a hydrological model. The modified slope stability analysis model, which was improved from 1-D infinite slope stability analysis model, has been taken into consideration of the flexion of the hill slopes. To evaluate its applicability to the prediction of landslides, the data of actual landslides were plotted on the predicted areas on the GIS map. The matching rate of this model to the actual data was 92.4%. And the relations between wetness index and landform factors and potential landslide were analyzed.

• Journal of Environmental Impact Assessment
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• v.10 no.2
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• pp.99-108
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• 2001

This study was performed to develop an information processing system for the sound conservation of soil and groundwater resources. The system contains numerical models and geographic information systems for underground flow and contamination. Multidimensional Finite Element Model for Subsurface Environment (MFEMSE) was invented to analyze underground flow and pollution problems of water and gas phases. Newly developed and conventional models (MODFLOW, MOC3D, MT3D, PMPATH, PEST, UCODE) were integrated with GIS (ArcView) for the construction of an integrated information management system of subsurface environment. This system was applied to the management of three mineral water companies located in clean high mountain basin. Desirable management criteria and operational strategies were suggested using this system. The system was constructed to be applied for the broad sense of decision supporting tools in related topics of this study, so that it can be used not only for the prevention regulations, but also for clean up projects.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.6 s.107
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• pp.23-35
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• 2005

Korean goral (Nemorhaedus caudatus raddeanus) is an endangered species in Korea, and the rugged terrain of the Sorksan National Park $(373km^2)$ is a critical habitat for the species. Since the goral population is threatened by habitat fragmentation, it is essential to establish a reserve for the isolated goral population. The objective of this study was to propose a reserve for Korean goral in the national Park We employed habitat suitability model, habitat capability model, and the concept of minimum viable population. The results of the study were as follows. First, the carrying capacity and optimal density of gorals in the national park were projected to be 449 gorals, and 251 gorals, respectively Second, since only one patch was projected to satisfy the criteria of minimum viable population (50 individuals/during 50 years), the long term extinction possibility of gorals in the site would be very high. Finally, the patch that satisfy the minimum viable population of goral was proposed as the core zone of the goral reserve and adjacent patches were included as buffer zones.

• Journal of Environmental Science International
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• v.20 no.1
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• pp.93-106
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• 2011

Physically-based resampling scheme for roughness coefficient of surface runoff considering the spatial landuse distribution was suggested for the purpose of effective operational application of recent grid-based distributed rainfall runoff model. Generally grid scale(mother scale) of hydrologic modeling can be greater than the scale (child scale) of original GIS thematic digital map when the objective basin is wide or topographically simple, so the modeler uses large grid scale. The resampled roughness coefficient was estimated and compared using 3 different schemes of Predominant, Composite and Mosaic approaches and total runoff volume and peak streamflow were computed through distributed rainfall-runoff model. For quantitative assessment of biases between computational simulation and observation, runoff responses for the roughness estimated using the 3 different schemes were evaluated using MAPE(Mean Areal Percentage Error), RMSE(Root-Mean Squared Error), and COE(Coefficient of Efficiency). As a result, in the case of 500m scale Mosaic resampling for the natural and urban basin, the distribution of surface runoff roughness coefficient shows biggest difference from that of original scale but surface runoff simulation shows smallest, especially in peakflow rather than total runoff volume.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.29-38
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• 1999

Present green space planning of Korea pay little attention to biodiversity conservation in urban areas. The quality of urban wildlife habitat has been deteriorated severely due to fragmentation and isolation of urban open spaces. The application of ecological corridors to urban green space planning and management can greatly enhance the bird habitat of Seoul. The objectives of this study were to evaluate bird habitat potential of existing urban parks of Seoul, and to investigate methods to develop ecological corridors for wild birds. This study consists of three parts. The first part is to construct bird species/habitat relationship model. The second part is to evaluate 207 urban parks of Seoul with the model. Based on the relative potential for bird habitat, urban parks of Seoul can be classified into cores, nodes, and points of the network. Outcomes of this part can also be used to enhance the quality of bird habitats by identifying limits or weakness of existing green spaces for bird habitat. The final part is to develop three green network plans; north-south network, the Han river network, and a district network for Kangnam-Gu.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.2
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• pp.15-25
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• 2004

For the effective operation of irrigation reservoirs, a general and systematic policy is suggested to make balance of the conflicting purposes between water conservation and flood control. In this study, the flood effective analysis system was developed through the integration of long-term water budget analysis model, GIS-based HEC-HMS model and HEC-RAS model. The system structure consists of long-term water budget model using modified TANK theory, flood runoff and flood effects analysis model using HEC-GeoHMS, HEC-HMS and HEC-RAS models. The flood effects analysis system simulated the flood runoff from the upstream, downstream flood and long-term runoff of the watershed using the observed data collected from 1998 to 2002 of Seongju dam. The simulated results were reasonably good compared with the observed data. The optimal management method of the reservoir during the whole season is suggested in this study, and the flood analysis system can be a useful tool to evaluate a reservoir operation quantitatively for the mitigation of flood damages of reservoir basin.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.2
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• pp.1-13
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• 2011

This study is to analyze the relationship between rainfall and water level using the measured data. During the rainfall event from September 9 to September 12, 2010, the rainfall and water level data were measured from automatic weather systems and automatic water level measurement systems which have been installed throughout Gangwon province. The result showed that the relationship between rainfall and peak flow change was different by basin and tributary. It is expected that this study will help to build a plan for preventing disasters and rainfall-runoff models for the river basins in Gangwon province.