• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.3
• /
• pp.133-145
• /
• 2010

This study analyzed the characteristics of sediment produce by landslide triggered by rainfall. One-dimensional unsaturated groundwater model and infinite slope stability analysis were used to estimate the behavior of soil moisture and slope stability according to rainfall, respectively. Slope stability analysis was performed considering on soil depth and characteristics of trees. As the results considering on recovery of the failed slopes, much amount of sediment was produced in 1963, 1970, and 2002. As the results of verification of simulation results using Landsat 5 TM images, we can find differences of landslide location between the results from model and satellite images. These differences can be caused by uncertainties of the rough parameters in the model. However, in the case that Obong-dam basin was divided into two subbasin, Wangsan-chun and Doma-chun basin, the results of each subbasin show errors around 20%. And only 4% of error occurred in the case of comparing landslide area on the entire Obong-dam basin. These errors seem insignificant considering on the errors which can be caused from the analyses in this study such as estimation of sediment produce, soil cover classification, and estimation of landslide area.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.16 no.3
• /
• pp.193-210
• /
• 2013

This study aims to assess the slope stability variation of Jeollabuk-do drainage areas by RCM model outputs based on A1B climate change scenario and infinite slope stability model based on the specific catchment area concept. For this objective, we downscaled RCM data in time and space: from watershed scale to rain gauge scale in space and from monthly data to daily data in time and also developed the GIS-based infinite slope stability model based on the concept of specific catchment area to calculate spatially-distributed wetness index. For model parameterization, topographic, geologic, forestry digital map were used and model parameters were set up in format of grid cells($90m{\times}90m$). Finally, we applied the future daily rainfall data to the infinite slope stability model and then assess slope stability variation under the climate change scenario. This research consists of two papers: the first paper focuses on the methodologies of climate change scenario preparation and infinite slope stability model development.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.3
• /
• pp.147-154
• /
• 2010

This study analyzed the characteristics of sediment produce by landslide triggered by rainfall. One-dimensional unsaturated groundwater model and infinite slope stability analysis were used to estimate the behavior of soil moisture and slope stability according to rainfall, respectively. Slope stability analysis was performed considering on soil depth and characteristics of trees. The results of the analysis on characteristics of sediment produce according to rainfall events showed that the sediment produce by landslide was mainly contributed to rainfall intensity and its temporal clustering. The results of the analysis on characteristics of sediment produce by extreme events showed that remaining rainfall amount of typhoon 'Rusa' was much more than that of the other extreme events, and thus this remaining rainfall was to contribute to sediment transportation. Additionally, only a small number of extreme events were found to cause most amount of sediment produce in a basin.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.159-163
• /
• 2009

CAT(Catchment hydrologic cycle Analysis Tool)은 기존 개념적 매개변수 기반의 집중형 수문모형과 물리적 매개변수 기반의 분포형 수문모형의 장점을 최대한 집약하여, 도시유역 개발 전 후의 장 단기적인 물순환 변화 특성을 정량적으로 평가하고 물순환개선시설의 효과적인 설계를 지원하기 위한 물순환 해석 모형이다. CAT은 수문학적으로 균일하게 판단되는 범위를 소유역으로 분할하여 지형학적 요인에 의한 유출 특성을 객관적으로 반영할 수 있으며, 개발 공간 단위별로 침투, 증발, 지하수 흐름 등의 모의가 가능하도록 하는 Link-Node 형식으로 개발되었다. 모형의 UI(User Interface)는 사용자가 손쉽게 모형을 적용 관리하고, 여러 시나리오를 동시에 효과적으로 모의하여 분석할 수 있도록 설계되었다. 또한 모든 입력 출력 자료를 Excel이나 텍스트 형식과 연동되도록 하여 프로젝트별 매개변수 관리가 용이하도록 개발하였다. CAT의 수문해석모듈로 증발산, 침투, 유역 유출, 지하수 유거, 하도추적 등의 모듈을 개발하였다. 증발산은 기준 증발산을 외부에서 직접 입력하거나, Penman-Monteith 방법을 선택할 수 있으며, 침투는 토양의 수리전도도에 따른 연직방향 침투 및 사면방향 복귀류를 고려할 수 있다. 노드의 지하수 유거를 고려하여 기존 노드-링크 방식 모형의 장기 유출 해석시 제한점을 보완하였으며, 하도추적을 위해 Muskingum, Muskingum-Cunge, Kinematic wave 방법 등의 해석법을 제공하였다. CAT의 수문모듈을 이용하여 설마천 유역을 단일노드 및 멀티노드로 개념화하여 모의하였으며, 모의결과를 관측유량과 비교한 결과, 두 경우 적절한 범위내의 결과임을 확인할 수 있었다. CAT의 안정적인 수문해석 기능을 바탕으로 향후 물순환개선시설 모듈과의 결합을 통해 장기 물순환 해석에 광범위하게 활용될 수 있을 것으로 판단된다.