Landsat NBR지수를 이용한 대형산불 피해지 구분 및 피해강도의 정량적 분석

원명수,구교상,이명보,Won,Myoung-Soo,Koo,Kyo-Sang,Lee,Myung-Bo 한국방재학회 2007 한국방재학회 학술발표대회논문집 Vol.2007 No.1

To monitor process of vegetation rehabilitation at the damaged area after large-fire is required a lot of manpowers and budgets. However the analysis of vegetation recovery using satellite imagery can be obtaining rapid and objective result remotely in the large damaged area. Space and airbone sensors have been used to map area burned, assess characteristics of active fires, and characterize post-fire ecological effects. Burn severity incorporates both short- and long-term post-fire effects on the local and regional environment. Burn severity is defined by the degree to which an ecosystem has changed owing to the fire. To classify fire damaged area and analyze burn severity of Samcheok fire area occurred in 2000, Cheongyang fire 2002, and Yangyang fire 2005 was utilized Landsat TM and ETM+ imagery. Therefore the objective of the present paper is to quantitatively classify fire damaged area and analyze burn severity using normalized burn index(NBR) of pre- and post-fire`s Landsat satellite imagery.

MODIS Fire Spot 정보와 5km 기상 재분석 자료를 활용한 접근불능지역의 산불기상위험지수 산출 모형 개발

원명수,장근창,윤석희,WON, Myoung-Soo,JANG, Keun-Chang,YOON, Suk-Hee 한국지리정보학회 2018 한국지리정보학회지 Vol.21 No.3

This study has developed a forest fire occurrence probability model for inaccessible areas such as North Korea and Demilitarized Zone and we have developed a real-time forest fire danger rating system that can be used in fire-related works. There are limitations on the research that it is impossible to conduct site investigation for data acquisition and verification for forest fire weather index model and system development. To solve this problem, we estimated the fire spots in the areas where access is impossible by using MODIS satellite data with scientific basis. Using the past meteorological reanalysis data(5㎞ resolution) produced by the Korea Meteorological Administration(KMA) on the extracted fires, the meteorological characteristics of the fires were extracted and made database. The meteorological factors extracted from the forest fire ignition points in the inaccessible areas are statistically correlated with the forest fire occurrence and the weather factors and the logistic regression model that can estimate the forest fires occurrence(fires 1 and non-fores 0). And used to calculate the forest fire weather index(FWI). The results of the statistical analysis show that the logistic models(p<0.01) strongly depends on maximum temperature, minimum relative humidity, effective humidity and average wind speed. The logistic regression model constructed in this study showed a relatively high accuracy of 66%. These findings may be beneficial to the policy makers in Republic of Korea(ROK) and Democratic People's Republic of Korea(DPRK) for the prevention of forest fires. 본 연구는 북한 및 비무장지대 등 접근불능지역에 대한 기상에 의한 산불발생예측 알고리즘을 개발하고, 실제 현장과 현업에서 활용할 수 있는 실시간 산불위험예보 체계를 개발하는데 있다. 산불기상위험지수 산출 모형 개발을 위해 자료의 취득과 검증을 위한 현장조사가 불가능하다는 연구적 한계가 존재하므로, 이를 해결하기 위해 MODIS 위성자료를 활용하여 접근이 불가능한 지역의 산불발화지점(fire spot)을 과학적 근거를 가지고 추정하였다. 추출된 산불발화지점을 대상으로 기상청에서 생산된 과거 기상 재분석자료(5㎞ 해상도)를 활용하여 산불발화지점에 대한 기상특성을 추출하여 데이터베이스화 하였다. 접근불능지역의 산불발화지점에서 추출된 기상요소들은 산불발생과 기상요인들과의 통계적 상관성과 산불발생 유무(산불발생 1, 산불 미발생 0)를 추정할 수 있는 로지스틱 회귀모형을 활용하여 실시간 기상변화에 의한 산불기상위험지수(Fire Weather Index, FWI)를 개발하였다. FWI 모형의 예측정확도는 66.6%로 나타나 모형의 적합도는 비교적 높은 것으로 나타났다. 이 연구결과는 남 북한의 산불 방지를 위한 정책 입안자들의 의사결정에 유용하게 활용될 것으로 기대한다.

초기 담수 중 콘크리트 표면차수벽형 석괴댐의 슬래브 거동에 관한 연구

원명수,김형주,정영채,Won, Myoung Soo,Kim, Hyeong Joo,Jung, Young Chae 대한토목학회 2015 대한토목학회논문집 Vol.35 No.1

차수기능을 점토 코아 대신 상류사면의 콘크리트 슬래브로 수행하는 콘크리트 표면차수벽형 석괴댐의 설계는 이론보다는 사례와 경험에 크게 의존한다. 본 연구에서는 두 개의 CFRDs에서 준공 후 초기 담수기간에 계측된 데이터를 근거로 콘크리트 슬래브와 누수량 거동을 분석하였다. 분석결과 슬래브의 변형률과 수직이음부의 수평변위는 미미하게 계절적인 온도 변화와 저수위면 증가에 의한 담수하중의 영향을 받고, 주변이음부의 변형은 온도 변화의 영향은 미미하고 담수하중의 영향을 크게 받는 것으로 나타났다. 그리고 누수량은 담수하중에 따른 주변이음부의 변형에 의한 영향을 크게 받는 것으로 나타났다. Concrete-Face Rock-Fill Dams (CFRDs) are rock-fill dams with watertight-concrete slabs on its upstream slope instead of its central earth cores. The design for CFRDs are still largely empirical and typically based on past experiences. This paper presents a description of the concrete face slabs and leakage behaviors of two post-constructed CFRDs based on the data gathered through instrumentation during the initial impoundment. The results show that the strain on the concrete face slab and the horizontal displacements of the vertical slab joints are slightly affected by both the seasonal temperature change and water loading during the initial impoundment. The deformation of perimetric joints are less affected by the temperature change, however it is significantly affected by the water loading during the initial impoundment. The leakage rate is significantly affected by the hydrostatic load and the deformation of the perimetric joints.

Bearing Capacity of Shallow Foundation on Geosynthetic Reinforced Sand

원명수,링호,김유성,Won Myoung-Soo,Ling Hoe I.,Kim You-Seong Korean Geotechnical Society 2004 한국지반공학회논문집 Vol.20 No.7

A series of model tests were conducted to investigate how the number of reinforcement layers, stiffnesses, types of reinforcement material and buried depth of a flexible pipe can affect bearing capacity-settlement curve at a loose sand foundation. In the test results, whereas the type of failure in unreinforced sand was local shear, the type of failure, for model tests with more than 2 reinforcement layers in loose sand, was general shear: The number of the optimum reinforcement layers was found to be two: Stiffness and type of reinforcement were more important than the maximum tensile strength of reinforcement in improving bearing capacity. When the depth of buried pipe from the sand surface was less than the width of the footing, test results showed that both bearing capacity and ultimate bearing capacity of buried pipe in unreinforced sand significantly decreased, and the type of failure in the reinforced sand changed from general shear to local shear. 느슨한 모래지반에서 보강재 층수 증가와 보강재의 강성과 형태 변화 그리고 얕은 기초 직하에 매설된 연성관의 깊이 등의 변화가 지지력-침하 곡선에 미치는 영향을 알아보기 위해 일련의 모형실험을 수행하였다. 시험결과, 무보강토 경우는 파괴형태가 국부전단으로 나타났으나 보강재 층수가 2층 이상이 되면 파괴형태는 국부전단에서 전반전단으로 바뀌고, 최적보강재 층수는 2층 이며, 지지력 개선에 있어서는 보강재의 초기강성과 형태가 최대인 장강도보다 중요한 것으로 나타났다. 무보강토에서 기초 직하에 연성관이 매설된 경우, 연성관의 매설 깊이가 기초 폭보다 얕으면 지지력과 극한지지력은 현저하게 감소하고, 보강토의 경우 연성관의 매설 깊이가 기초 폭보다 얕으면 파괴형태는 전반전단에서 국부전단으로 바뀌는 것으로 나타났다.

토목섬유의 봉합강도에 관한 연구

원명수(Myoung-Soo Won),이장백(Jang-Baek Lee),김기준(Ki-Joon Kim),김형주(Hyeong-Joo Kim) 한국지반신소재학회 2013 한국토목섬유학회 학술발표회 Vol.2013 No.11

A serious of geotextile seam tests were performed with varying number of seam stitches and separation distance. The seam strength is affected by the amount of seam stitches and stitch distance. The seam strength was remarkably increased for the case with two six-line stitch with 5cm separation distance.

15개월 간 현장 계측결과에 근거한 보강토 옹벽 내 토목섬유 보강재의 변형 거동에 관한 연구

원명수(Won, Myoung-Soo),란쿠안 크리스틴(Langcuyan, Christine P),할더산차리(Halder Sanchari),김유성(Kim, You-Seong) 한국지반신소재학회 2016 한국지반신소재학회 학술발표회 Vol.2016 No.10

붕괴된 보강토옹벽 복구 사례

원명수(Myoung-Soo Won),최용훈(Yong-Hun Choi),최정호(Jeong-Ho Choi),김유성(You-Seong Kim) 한국지반신소재학회 2012 한국토목섬유학회 학술발표회 Vol.2012 No.11

The present paper introduces the case which rehabilitates a collapsed geosynthetics reinforced segmental retaining wall by soil nailing. The feature of at this case rehabilitates a callapsed GRS retaining wall without backfill excavation. This rehabilitation technique without backfill excavation is expected the construction work is easy and the economical efficiency is excellent.

SPOT5영상과 현장조사자료를 융합한 대형산불지역의 피해강도 분석

원명수 ( Myoung Soo Won ),김경하 ( Kyong Ha Kim ),이상우 ( Sang Woo Lee ) 한국농림기상학회 2014 한국농림기상학회지 Vol.16 No.2

For classifying fire damaged areas and analyzing burn severity of two large-fire areas damaged over 100 ha in 2011, three methods were employed utilized supervised classification, unsupervised classification and Normalized Difference Vegetation Index (NDVI). In this paper, the post-fire imageries of SPOT were used to compute the Maximum Likelihood (MLC), Minimum Distance (MIN), ISODATA, Kmeans, NDVI and to evaluate large-scale patterns of burn severity from 1 m to 5 m spatial resolutions. The result of the accuracy verification on burn severity from satellite images showed that average overall accuracy was 88.38 % and the Kappa coefficient was 0.8147. To compare the accuracy between burn severity and field survey at Uljin and Youngduk, two large fire sites were selected as study areas, and forty-four sampling plots were assigned in each study area for field survey. The burn severities of the study areas were estimated by analyzing burn severity (BS) classes from SPOT images taken one month after the occurrence of the fire. The applicability of composite burn index (CBI) was validated with a correlation analysis between field survey data and burn severity classified by SPOT5, and by their confusion matrix. The result showed that correlation between field survey data and BS by SPOT5 were closely correlated in both Uljin (r = -0.544 and p<0.01) and Youngduk (r = -0.616 and p<0.01). Thus, this result supported that the proposed burn severity analysis is an adequate method to measure burn severity of large fire areas in Korea.

아크릴 토조를 이용한 주입형태에 따른 준설토의 퇴적분포형상 고찰

원명수(Myoung-Soo Won),제이제민(Jay C. Jamin),최민준(Min-Jun Choi),박태웅(Tae-Woong Park) 한국지반신소재학회 2014 한국지반신소재학회 학술발표회 Vol.2014 No.4

In this study the effects of the injection inlet type used to the sediment distribution of the dredged soil fill for geotextile tubes are examined. A series of experiments with 1-type and T-type injection modules are performed to examine the distribution of dredged soil fill inside an acrylic cell. The test results showed that the 1-type injection module generates a crater phenomenon within the cell while the T-type injection module produces an evenly distributed sediments without crater formation.

콘크리트 표면차수벽형 석괴댐의 슬래브 거동에 관한 연구

원명수(Won, Myoung Soo),김형주(Kim, Hyeong Joo),송영철(Song, Young Chul),김유성(Kim, You Seong) 대한토목학회 2013 대한토목학회 학술대회 Vol.2013 No.10