• Journal of Korean Society of Disaster and Security
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• v.14 no.4
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• pp.37-45
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• 2021

Flooding damage may occur due to an unexpected increase in rainfall in summer. Previously, the roughness coefficient, which is a major factor of conveyance, was calculated through on-site measurement, but in case of on-site measurement, there are many limits in accurately grasping changes in vegetation. In this study, the vegetation index (NDVI) was calculated using the Sentinel-2 optical images, and the modified roughness coefficient was calculated through the density and distribution area of the vegetation. Then the calculated roughness coefficient was applied to HEC-RAS 1D model and verified by comparing the results with the water level at the water level station directly downstream of the Soyang River dam. As a result, the error rate of the water level decreased about 14% compared to applying the previous roughness coefficient. Through this, it is expected that it will be possible to refine the flood level of rivers in consideration of seasonal flood characteristics and to efficiently maintain rivers in specific sections.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1D
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• pp.203-209
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• 2006

SAR (Synthetic Aperture Radar) technology, which is not influenced by cloud cover because of using electromagnetic wave of long wavelength, has an advantage in mapping the earth. NASA, recognizing these strong points of SAR, launched SRTM (Shuttle Radar Topography Mission), and acquired the topographic information of the earth. SRTM and NED (National Elevation Data) of USGS were used for the research and vegetation height map was produced through differentiating the two data. Correlation between SRTM-NED and planting year was analyzed to see the relationship. Strong correlation was detected and it shows the feasibility of estimating timber age and eventually creating timber age map from SRTM-NED. Additional analyses were conducted to check if the linearity is influenced by regional characteristics and forest uniformity. As results, the correlation between SRTM-NED and timber age is influenced by roughness of the terrain. Overall, this paper shows that timber age estimation using SRTM and NED can be sufficiently practical.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.695-707
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• 2019

This study was intended to suggest the appropriate vegetation management methodology by analyzing phytosociology for ecotourism resources. We carried out the classification and interpretation of the vegetation structure and the analysis of the relationship between communities and environmental conditions in Pocheon valley, Mt. Gaya. The vegetation in Pocheon valley was composed of 5 communities: Pinus densiflora-Quercus mongolica community, Quercus serrata-Quercus variabilis community, Larix kaempferi-Quercus serrata community, Pinus densiflora-Castanea crenata community, and Salix gracilistyla-Phragmites japonica community. The Quercus serrata-Quercus variabilis community was further segmented into two types according to the differences of composition species and location of habitats. The methodologies that satisfy both the use of nature for ecotourism resources and the sustentation of natural vegetation are as follows: - maintenance the present vegetation (dominance species) by strictly avoiding artificial management in the tree layer; - maintenance of the existing vegetation structure through the artificial management of the usual vigorous tree species when the species in the shrub layer grow up to the subtree layer; and - continued artificial management to maintain high balanced diversity and evenness of various species in shrub and herb layers.

• Journal of Environmental Impact Assessment
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• v.31 no.6
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• pp.409-422
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• 2022

Riverine wetlands are an important element of the river ecosystem and account for approximately 38% of the inland wetlands surveyed so far. The Shincheon Wetland located in Mangyeong River is also a channel wetland as the flow rate is slowed by the constructed weirs, leading to sediment accumulation. To identify the conservation value and ecological characteristics of Shincheon Wetland, its vegetation and plant diversity were identified using a phytosociological method, and a total of 45 vegetation-related datasets were collected. Overall, 24 plant communities, comprising a total of 153 taxa (49 families, 117 genera, 146 species, 2 subspecies, 5 varieties) were identified. The plant with the highest appearance rate in the communities was Humulus japonicus Siebold & Zucc. In addition, annual herb species, including Rumex crispus L., Bromusjaponicus Thunb., Erigeron annuus (L.) Pers., and Artemisia indica Willd. were frequently observed to be growing in the secondary grassland. Naturalized plants were surveyed in the 38 taxa; the urbanization index was 10.3% and the naturalized index was 24.8%. Plant communities were largely classified into submerged vegetation, floating and floating-leaved vegetation, annual and biennial vegetation, perennial herb vegetation, and woody vegetation. The distribution of plant communities reflecting various habitats, including the lentic and lotic zone maintaining a constant water depth, littoral zone experiencing intermittent water level fluctuations, and dry floodplain environment was also confirmed. Overall, plant community development plays an important role in the habitat for wild animals; therefore, it is expected to positively impact biodiversity enhancement.

• Korean Journal of Environment and Ecology
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• v.9 no.2
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• pp.211-220
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• 1996

5 major trails of Odaesan National Park were selected to investigate the use impacts on environmental deterioration of trail accreding to the different amunt of use. The entire width, bare width, maximum depth and slope of trail as the trail comdition surveyed at the total of 120 points were significantly greater on the more heavily-used trail. Major deterioration types of trail were root-exposure, rock-exposure, deepening and divergence in order of frquency and trail conditions of deteriorated points were significantly different from those of non-deteriorated points. The damaged area more severe than Class 4 on trail reached about 379m$^{2}$/km in total, and especcially about 1,196m$^{2}$/km in the section between Chodmyolbogung and Pirobong of Sangwonsa trail. The dominant trees of trail edge vegetation could be Quercus mongolica in upper layer, but in lower layer Rhododecdron schilipenbachii for slope and Actinidia arguta for ridge. Coverage and number of individuals of lower vegetation in trail edge were the lowest on the Sangwonsa trail of the largest use amount, and each trail was dissimilar in species composition of lower layer of edge vegetation.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.161-161
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• 2021

본 연구에서는 금강 상류의 용담댐 유역(930.0 km²)을 대상으로 Sentinel-1 SAR(Synthetic Aperture Radar) 및 Sentinel-2 MultiSpectral Instrument(MSI) 위성영상을 활용한 토양수분 산출연구를 수행하였다. 연구에 사용된 자료는 10 m 해상도의 Sentinel-1 IW(Interferometric Wide swath) mode GRD(Ground Range Detected) product의 VV(Vertical transmit-Vertical receive) 및 VH(Vertical transmit-Horizontal receive) 편파자료와 Sentinel-2 Level-2A Bottom of Atmosphere(BOA) reflectance 자료를 2019년에 대해 각 6일 및 5일 간격으로 구축하였다. 위성영상의 Image processing은 SNAP(SentiNel Application Platform)을 활용하여 Sentinel-1 영상의 편파 별(VV, VH) 후방산란계수와 Sentinel-2의 적색(Band-4) 및 근적외(Band-8) 영상을 생성하였다. 토양수분 산출 모형은 다중선형회귀모형(Multiple Linear Regression Model)을 활용하였으며, 각 지점에 해당하는 토양 속성별로 모형을 생성하였다. 모형의 입력자료는 Sentinel-1 위성의 편파별 후방산란계수, Sentinel-1 위성에서 산출된 식생지수 RVI(Radar Vegetation Index)와 Sentinel-2 위성에서 산출된 NDVI(Normalized Difference Vegetation Index)를 활용하여 식생의 영향을 반영하고자 하였다. 모의 된 토양수분을 검증하기 위해 6개 지점의 TDR(Time Domain Reflectometry) 기반 실측 토양수분 자료를 수집하고, 상관계수(Correlation Coefficient, R), 평균제곱근오차(Root Mean Square Error, RMSE) 및 IOA(Index of Agreement)를 활용하여 전체 기간 및 계절별로 나누어 검증할 예정이다.

• Proceedings of the KGS Conference
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• 2003.11a
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• pp.34-39
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• 2003

밀양강 중류부 충적평야의 화분분석 결과를 통하여 홀로세 후기 동안의 식생환경을 복원하고 한반도 남부지방의 농경의 기원과 확산에 대해 검토하였다. 경상남도 밀양시 산외면 금천리 단장천 충적평야에서 화분분석을 행하였다. 고고학 유적발굴을 위해 절개한 트랜치 T6(14.75-15.90m a.s.l. : 두께 1.15m)과 T9(17.00-15.60m a.s.l. : 두께 1.4m)의 노두 단면 중에서 비교적 유기질이 풍부한 실트층 및 토탄층에서 5cm등간격으로 채취하여 목본화분(AP: Arboreal Pollen)이 200개 이상이 될 때까지 검경하였다. (중략)

• Korean Journal of Environment and Ecology
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• v.14 no.1
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• pp.88-98
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• 2000

본 연구는 국립공원의 산림관리에 필요한 기초자료를 제공하고자 계곡부식생을 조사하였다 계룡산국립공원의 계곡부식생을 ZM학과의 식물사회학적인 방법으로 분류한 결과 까치박달군락으로 구분되었다 까치박달군락은 다시 고로쇠나무아군락, 조릿대아군락, 병꽃나무아군락 등 3개의 아군락으로 서어나무군락은 쥐똥나무아군락 쪽동백아군란 등 2개의 아군락으로 구분되었다 까치박달군락은 서어나무군락보다 해발고가 높고 습한 지역에 분포하였다 또한 동일한 계곡이라 할지라도 입지조건 중 특히 계곡부가 위치해 있는 사면의 방위에 따라 식생구성의 차이를 나타냈다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.11a
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• pp.425-426
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• 2006

청원군 소재 한국 교원대 내부 산과 인근 산에 발생한 산불에 의한 식생의 변화를 1년10개월 지난 뒤 조사 연구하였다. 조사 방법은 대상법을 사용하여 종 조사와 건중량을 조사하였다. 우점종은 방향구에서 발견된 종 빈도를 바탕으로 산출하였다. 산불이 일어난 지역은 식물상 조사 결과, 졸참나무, 산딸기, 그늘사초가 우점종으로 나왔다.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.33-40
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• 2013

From March 2012 to January 2013, this study was conducted as a part of the project for making a precise electronic ecological zoning map of vegetation on a highly reduced scale of 1 to 5,000 with a view to improving management efficiency of national parks and enlarging the availability of the data produced from the basic research monitoring the resources of national parks. For the research accuracy and rapidity, a vegetation map was specially created for the on-the-site-vegetation research. To make the map more meticulous, we categorized the vegetation database into five groups: broadleaved forest, coniferous forest, mixed forest, rock vegetation and miscellaneous one. After comparing the results of the data built for the vegetation research and the actual research findings, it was made clear that vegetation of both categories was almost the same in case of broad-leaved forest with 72.20% and 78.45% respectively, and also equivalent in other groups like, for example, coniferous forest (16.70%, 13.41%), mixed forest (9.50%, 7.49%) and rock vegetation (0.60%, 0.15%). According to the precise vegetation map produced from the research, the deciduous broad-leaved forest was the most widely prevalent type in the correlated hierarchical classification of vegetation, occupying 65.78% of the overall vegetation. It was followed by mountain valley forest (15.17%), coniferous forest (10.90%), and plantation forest (7.00%) in order. It is particularly noteworthy that Mt. Deogyusan national park has retained a very stable and versatile forest vegetation in the outstanding state since approximately 20% of the mountain turns out to belong to the I grade vegetation conservation classification which contains climax forests, unique vegetation, subalpine vegetation, matured stands which are older than 50 years and etc.