• 제목/요약/키워드: vegetation

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연안식생에 의한 표사이동 특성에 관한 수치해석 (Numerical Analysis for Wave Propagation and Sediment Transport with Coastal Vegetation)

  • 이성대
    • 한국해양공학회지
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    • 제21권5호
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    • pp.18-24
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    • 2007
  • The environmental value of coastal vegetation has been widely recognized. Coastal vegetation such as reed forests and seaweed performs several useful functions, including maintaining water quality, supporting fish (and, thus, fisheries), protecting beaches and land from wave attack, stabilizing sea beds and providing scenic value. However, studies on the physical and numerical process of wave propagation, sediment transport and bathymetric change are few and far between compared to those on the hydrodynamic roles of coastal vegetation. In general, vegetation flourishing along the coastal areas attenuates the incident waves through momentum exchange between stagnated water mass in the vegetated area and rapid mass in the un-vegetated area. This study develops a numerical model for describing the wave attenuation and sediment transport in a wave channel in a vegetation area. By comparing these results, the effects of vegetation properties, wave properties and model parameters are clarified.

임도시공경과년수 및 물리적 특성이 임도사면의 식생 침입에 미치는 영향 (Influence of Elapsed Years and Physical Properties on Vegetation Invasion of Forest Road Slope)

  • 이준우;추갑철;최윤호
    • 한국환경복원기술학회지
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    • 제5권1호
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    • pp.28-34
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    • 2002
  • This study was carried out to analyze the effects of elapsed years and physical properties on invaded vegetation of forest road slope. For the study, 8 forest roads in Asan-si of Chungcheongnam-do were selected and 15 factors that might influence on vegetation invasion were analyzed. In generally, vegetation coverage of slope have increased with the elapsed years. But invasion species have decreased in the cut-slope and increased in fill-slope. There was no significant correlation between rate of vegetation coverage and elapsed years, but rate of vegetation coverage was strongly related with slope aspect. And the species of invasion vegetation affected mostly by the elapsed years and slope aspect among the physical properties.

도시림의 생태학적 진단과 생태적 관리시스템 개발 : 부산시 황령산을 중심으로 (Ecological diagnosis and Development of Ecological Management System of Urban Forest : On Mt. Hwangryung in Pusan, Korea)

  • 조현제;이창석
    • The Korean Journal of Ecology
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    • 제21권6호
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    • pp.779-789
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    • 1998
  • The forest vegetation established on Mt. Hwangryung located in Pusan, southern Korea was analyzed through phytosociological procedure. Vegetation of the study area was categorized into 14 communities, 16 groups, and 13 subgroups. Vegetation units obtained from such an analysis were shown in a detailed vegetation map (scale 1:5,000). Ecological characteristics of each vegetation unit were discussed on the basis of the principle of restoration ecology. From those results, it was confirmed that some introduced vegetation under excessive artificial interference was in unstable state and then ecological restoration was needed. On the other hand, ecological information and management systems to maintain the urban forest as ecologically healthy state were developed using GIS.

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용담댐시험유역 기상자료와 식생지수의 상관성 분석 (Relationship between Vegetation Index and Meteorological Element in Yongdam Catchment)

  • 이형근;황지형;이길하
    • 한국환경과학회지
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    • 제27권11호
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    • pp.983-989
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    • 2018
  • The real-time monitoring of surface vegetation is essential for the management of droughts, vegetation growth, and water resources. The availability of land cover maps based on remotely collected data makes the monitoring of surface vegetation easier. The vegetation index in an area is likely to be proportional to meteorological elements there such as air temperature and precipitation. This study investigated relationship between vegetation index based on Moderate Resolution Image Spectroradiometer (MODIS) and ground-measured meteorological elements at the Yongdam catchment station. To do this, 16-day averaged data were used. It was found that the vegetation index is well correlated to air temperature but poorly correlated to precipitation. The study provides some intuition and guidelines for the study of the droughts and ecologies in the future.

백두대간 바람재일대 식생유형 및 천이경향 (Successional Trends and Vegetation Types in the Baramjae Area of Baekdudaegan)

  • 김지동;이준우;박병주;이혜정;이동혁;허태임;변준기;안지홍
    • 한국산림과학회지
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    • 제109권3호
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    • pp.249-258
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    • 2020
  • 본 연구는 바람재일대의 산림생태계복원 이후 식생유형에 따른 천이경향에 대한 산림의 변화 상태를 분석하였다. 바람재일대의 식생유형 분류를 위해 2019년 5월부터 10월까지 식생조사법에 따라 총 81개소를 조사하였다. 그 결과 식생유형분류체계는 소나무군락군으로 구분되었다. 군락단위에서 신갈나무군락, 소나무전형군락으로 구분되었다. 군단위에서 떡갈나무전형소군, 버드나무소군, 신갈나무전형소군으로 구분되었다. 중요치 분석 결과, 식생단위 1은 신갈나무, 굴참나무, 식생단위 2는 신갈나무, 떡갈나무, 식생단위 3은 소나무, 그리고 식생단위 4는 버드나무의 중요치가 높게 나타났으며, 천이계열에 따라 층위별 이입 종의 우점도 차이를 보였다. 식생유형분류체계를 바탕으로 천이경향을 파악하기 위해 Detrended Correspondence Analysis(DCA)를 분석한 결과, 1축(33.2%) 및 2축(28.9%)로 종합 설명력 62.1%로 나타났다. 복원 이후, 천이경향은 식생단위 1과 식생단위 2가 가장 광범위한 식생으로 발달한 것으로 판단되었다. 식생단위 2와 식생단위 4에 해당하는 버드나무소군은 초기식생 발달에 이입된 종이 다수 분포하고 있었다. 이에 따라 바람재 일대는 단계적 천이계열로 판단되었다.

서울시 식생부문 온실가스-대기오염 통합 흡수/배출량 인벤토리 및 환경가치분석 (GHG-AP Integrated Sink/Emission Inventories and Environmental Value Analysis in Vegetation Sector of Seoul)

  • 정재형;권오열
    • 한국대기환경학회지
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    • 제31권1호
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    • pp.72-82
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    • 2015
  • We constructed greenhouse gas (GHG) and air pollution (AP) integrated sink/emission inventories and evaluated the environmental value for the vegetation sector in Seoul during year 2010. The data of vegetation, classified into four sectors of cultivated land, forest land, park and street tree, were obtained from Statistics Korea and Seoul City. Based on the previous studies, only $CO_2$ was chosen as GHG sink by vegetation. $NO_2$ and $SO_2$ were chosen as AP sink by vegetation, while isoprene, monoterpene, other VOC (OVOC) and NH3 were chosen as AP emission from vegetation. Estimation methodology and sink/emission factors were gathered from reports and published literatures. Estimated GHG sink by vegetation during year 2010 was 12,987,173 $tonCO_{2eq}$, of which approximately 1/4 was from pure vegetation and the remaining 3/4 from vegetation soil. AP sink and emission were estimated to be 23,309 tonAP and 2,629,797 tonAP, respectively. The analysis by administrative districts in Seoul revealed that among 25 districts, Seocho-gu, Nowon-gu, Eunpyeong-gu, Gwanak-gu and Gangbuk-gu were the major districts in GHG and AP sink/emission inventories for vegetation sector. Environmental value of vegetation as a function of GHG and AP sink, was estimated as 800 billion won, corresponding to 5% of the total cost of the forest land in Korea evaluated as a public function.

도시도로 녹지의 도로 표면온도 져감 효과에 관한 연구 (The Effect of Urban Road Vegetation on a Decrease of Road Surface Temperature)

  • 조혜진;임지현
    • 한국조경학회지
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    • 제39권3호
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    • pp.107-116
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    • 2011
  • 도시의 온도상승의 주요 인자 중 하나가 도시부 도로이다. 본 연구의 목적은 도시도로 녹지가 표면온도의 저감에 영향을 미치는 요인을 파악하는 것이다. 이를 위해 서울시 도로 18개 지점을 선정하여 도로횡단구성요소(주변토지이용, 차도, 보도, 식수대, 중앙분리대)별로 열화상 카메라로 표면온도를 조사하고, 도시도로 녹지 면적을 측정하였다. 도시도로 녹지의 도로 표면온도 저감에 미치는 영향을 분석한 결과 도로 주변토지이용이 녹지 및 오픈스페이스일 경우 도로온도에 미치는 영향이 가장 크며, 식생중앙분리대의 면적, 식수대의 면적 순으로 표면온도를 저감시키는 것으로 나타났다. 도로주변 뿐만 아니라 도로설계의 구성요소 내에서 식수대, 중앙분리대 등의 녹지면적 증가는 도로의 표변온도 저감에 영향을 미친다. 도시의 고온화현상을 완화하기 위하여 도시도로 녹지 면적을 증가시키는 것도 한 방편이다.

SPOT/VEGETATION NDVI 자료를 이용한 북한지역 식생 변화 탐지 (A Detection of Vegetation Variation Over North Korea using SPOT/VEGETATION NDVI)

  • 염종민;한경수;이창석;박윤영;김영섭
    • 한국지리정보학회지
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    • 제11권2호
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    • pp.28-37
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    • 2008
  • 본 연구에서는 원격탐사자료를 이용하여 현장관측이 불가능한 북한 지역에 대한 NDVI (Normalized Difference Vegetation Index) 산출을 통하여 1999년부터 2005년까지 7년간의 지표 상태 모니터링 하였다. 북한의 산림 지역은 소위 한반도의 폐라고 불리며, 한반도 내에서 가장 풍부한 산림지역이 위치하고 있다. NDVI는 식생의 활력 지수를 나타내며, 유사한 많은 연구에서 사용되었다. 본 연구에서는 북한 지역 식생의 변화를 탐지하고 그 원인을 분석하였다. NDVI의 변동은 북한 지역에서 가뭄이나 태풍의 영향을 잘 반영하고 있으며, 북한 지역이 태풍이나 가뭄을 겪고 있을 때 평년보다 낮은 NDVI 수치가 나타났다. 특히, 최근 정치적, 경제적으로 큰 이슈가 되고 있는 북한 지역 식량 생산 정보이 간접적인 파악을 위해 본 연구에서 분석한 결과를 토대로 식량 생산 동향을 유추하였다.

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Comparison of field- and satellite-based vegetation cover estimation methods

  • Ko, Dongwook W.;Kim, Dasom;Narantsetseg, Amartuvshin;Kang, Sinkyu
    • Journal of Ecology and Environment
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    • 제41권2호
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    • pp.34-44
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    • 2017
  • Background: Monitoring terrestrial vegetation cover condition is important to evaluate its current condition and to identify potential vulnerabilities. Due to simplicity and low cost, point intercept method has been widely used in evaluating grassland surface and quantifying cover conditions. Field-based digital photography method is gaining popularity for the purpose of cover estimate, as it can reduce field time and enable additional analysis in the future. However, the caveats and uncertainty among field-based vegetation cover estimation methods is not well known, especially across a wide range of cover conditions. We compared cover estimates from point intercept and digital photography methods with varying sampling intensities (25, 49, and 100 points within an image), across 61 transects in typical steppe, forest steppe, and desert steppe in central Mongolia. We classified three photosynthetic groups of cover important to grassland ecosystem functioning: photosynthetic vegetation, non-photosynthetic vegetation, and bare soil. We also acquired normalized difference vegetation index from satellite image comparison with the field-based cover. Results: Photosynthetic vegetation estimates by point intercept method were correlated with normalized difference vegetation index, with improvement when non-photosynthetic vegetation was combined. For digital photography method, photosynthetic and non-photosynthetic vegetation estimates showed no correlation with normalized difference vegetation index, but combining of both showed moderate and significant correlation, which slightly increased with greater sampling intensity. Conclusions: Results imply that varying greenness is playing an important role in classification accuracy confusion. We suggest adopting measures to reduce observer bias and better distinguishing greenness levels in combination with multispectral indices to improve estimates on dry matter.

Analysis of Hydraulic Characteristics According to the Cross-Section Changes in Submerged Rigid Vegetation

  • Lee, Jeongheum;Jeong, Yeon-Myeong;Kim, Jun-Seok;Hur, Dong-Soo
    • 한국해양공학회지
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    • 제36권5호
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    • pp.326-339
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    • 2022
  • Recently, not only Korea but also the world has been suffering from problems related to coastal erosion. The hard defense method has been primarily used as a countermeasure against erosion. However, this method is expensive and has environmental implications. Hence, interest in other alternative methods, such as the eco-friendly vegetation method, is increasing. In this study, we aim to analyze the hydraulic characteristic of submerged rigid vegetation according to the cross-sectional change through a hydraulic experiment and numerical simulation. From the hydraulic experiment, the reflection coefficient, transmission coefficient, and energy dissipation coefficient were analyzed according to the density, width, and multi-row arrangement of the vegetation zone. From numerical simulations, the flow field, vorticity distribution, turbulence distribution, and wave distribution around the vegetation zone were analyzed according to the crest depth, width, density, and multi-row arrangement distance of the vegetation zone. The hydraulic experiment results suggest that the transmission coefficient decreased as the density and width of the vegetation zone increased, and the multi-row arrangement condition did not affect the hydraulic characteristics significantly. Moreover, the numerical simulations showed that as the crest depth decreased, the width and density of vegetation increased along with vorticity and turbulence intensity, resulting in increased wave height attenuation performance. Additionally, there was no significant difference in vorticity, turbulence intensity, and wave height attenuation performance based on the multi-row arrangement distance. Overall, in the case of submerged rigid vegetation, the wave energy attenuation performance increased as the density and width of the vegetation zone increased and crest depth decreased. However, the multi-row arrangement condition did not affect the wave energy attenuation performance significantly.