• Title/Summary/Keyword: vegetation change

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Rule set of object-oriented classification using Landsat imagery in Donganh, Hanoi, Vietnam

  • Thu, Trinh Thi Hoai;Lan, Pham Thi;Ai, Tong Thi Huyen
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.6_2
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    • pp.521-527
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    • 2013
  • Rule set is an important step which impacts significantly on accuracy of object-oriented classification result. Therefore, this paper proposes a rule set to extract land cover from Landsat Thematic Mapper (TM) imagery acquired in Donganh, Hanoi, Vietnam. The rules were generated to distinguish five classes, namely river, pond, residential areas, vegetation and paddy. These classes were classified not only based on spectral characteristics of features, but also indices of water, soil, vegetation, and urban. The study selected five indices, including largest difference index max.diff; length/width; hue, saturation and intensity (HSI); normalized difference vegetation index (NDVI) and ratio vegetation index (RVI) based on membership functions of objects. Overall accuracy of classification result is 0.84% as the rule set is used in classification process.

Estimation for Changes of Net Primary Productivity and Potential Natural Vegetation in the Korean Peninsula by the Global Warming (地球 溫暖化에 따른 韓半島의 純一次生産力과 潛在自然植生의 變化 推定)

  • Kim, Jeong-Un;Kil, Bong-Seop
    • The Korean Journal of Ecology
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    • v.19 no.1
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    • pp.1-7
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    • 1996
  • The net primary productivity and potential natural vegetation in the Korean peninsula in the 21st century were estimated by the Miami model and thermal climate, respectively, based on 148 meteorological data sets. In the 21st century, the distribution range of the net primary produtivity in the Korean peninsula was estimated as 1,050 g $DM{\cdot}m^{-2}{\cdot}yr^{-1}~2,050g\;DM\cdot m^-2\cdot yr^{-1}.\; These\; values\; increased\; by\; 200g\; DM\cdot m^{-2}\cdot yr^{-1}\;on\;northern\;part\;and\;400g\; DM\cdot m^{-2}\cdot yr^{-1}$ on southern part compared with that of the present century. The potential natural vegetation in the Korean peninsula in the 21st century will change into the followings:coniferous forest on Mt. Paektu area, deciduous broadleaf forest on northern part, and evergreen broadleaf forset on southern part.

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Estimation of NPP Distribution using NOAA/AVHRR (NOAA/AVHRR 자료를 이용한 순일차생산량 분포 추정)

  • 신사철;유철상
    • Journal of Environmental Science International
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    • v.6 no.6
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    • pp.605-612
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    • 1997
  • This study is to evaluate the overall NPP(Net Primary Productions distribution in the Korean Peninsula from the satellite data(NOAA/AVHRR). This has been done using the linear relationship between the natural vegetation condition and the NPP. The NPP of natural vegetation increases proportional to the annual net radiation(Rn), where radiative dorless Index(RDI) is a proportional constant connecting Rn to NPP. Normalized Difference Vegetation Index(NDVI) Is used for monitoring vegetation change, and INDVI (Integrated NDVI) for annual analysis. The INDVI has a close relation to .Rn and NPP. which can be used effectively for estimating NPP distribution of where the meteorological data Is unavailable such as North Korea. The NPP distribution of the Korean Peninsula was estimated based on the model.

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The Satellite Observation for Spatial Changes of Vegetation in Saemangum Tidal Flat (새만금 갯벌의 식생 공간변화에 대한 위성관측)

  • Jeong, Jong-Chul
    • Journal of Environmental Impact Assessment
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    • v.23 no.2
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    • pp.150-156
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    • 2014
  • The aim of this study is to detection of changed vegetation area of Saemangeum tidal flat with comparison of topography and surface sediments during the dyke construction. Sedimentary facies of four seasons of 2001 from inside Saemangeum tidal flat revealed homogeneous layers in the upper part, however near sea side tidal flat were detecting with carried out rapid sediment deposition during the dyke construction using satellite image spatial analysis. The sedimentation types inside Saemangeum tidal flat were classified with vegetation types, which were well matched with the sedimentation pattern revealed by change in vegetation patterns.

A NEW VEGETATION INDEX FOR REMOTE SENSING

  • Iisaka, Joji;Takako, Sakurai-Amano
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.256-261
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    • 1999
  • Global vegetation change is one of major global concerns. Remote sensing images provide an efficient and useful data source to estimate global vegetation covers, and a number of methods have been proposed to estimate them. Among them, the NDVI is one of the most popular indices, and it is_easy to calculate with simple image computing. However, this index is very much affected by the radiometric environment of sensing such as atmospheric conditions and the sun illumination angle. Therefore, it is not appropriate to apply the NDVI to investigate seasonal changes. This paper discusses these problems and proposes an alternative index, MODVI(Modified Vegetation Index), that is less affected by radiometric environment changes. An experiment was conducted to compare these two indices using temporal Landsat TM sub-scenes.

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On the Impacts to the Loca l Climate Change of Urban Area due to the Vegetation Canopy (녹지대 분포가 도시 지역의 소기후에 미치는 영향)

  • 진병화;변희룡
    • Journal of Environmental Science International
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    • v.9 no.2
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    • pp.101-108
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    • 2000
  • Through numerical experiment using simplified OSU-1D PBL(Oregon State University One-Dimensional Planetary Boundary Layer) model and field measurement, we studied the impacts of vegetation canopy on heat island that was one of the characteristics of local climaate in urban area. it was found that if the fraction of vegetation was extended by 10 percent, the maximum air temperature and the maximum ground temperature can come down about 0.9${\circ}C$, 2.3${\circ}C$, respectively. Even though the field measurement was done under a little unstable atmospheric condition, the canopy air temperature was lower in the daytime, and higher at night than the air and ground temperature. This result suggests that the extention of vegetation canopy can bring about more pleasant local climate by causing the oasis, the shade and the blanket effect.

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Assessment of environmental impacts of LID technologies on vegetation

  • Choi, Hyeseon;Hong, Jungsun;Geronimo, F.K.F.;Kim, Lee-Hyung
    • Membrane and Water Treatment
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    • v.10 no.1
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    • pp.39-44
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    • 2019
  • LID facilities do not consider environmental factors, and due to inappropriate vegetation planting causing degradation in efficiency due to plant damage and difficulty in maintenance. Therefore, in this study, assessment of impact environmental factor by seasonal variation of chlorophyll and growth of vegetation planted in LID technologies and change of pollutant reduction were conducted. In the case of B-SJ and B-RI, growth rate decreased after summer (August), and B-MG showed steady growth until autumn (September). Chlorophyll was found to increase during spring season while it decreased during autumn season. The chlorophyll concentration was found to affect the plant growth pattern. TN reduction efficiency was highest with greater than 80% efficiency in summer, and it was analyzed that plants were identified as the main factor affecting the seasonal reduction efficiency of TN. Also, temperature and relative humidity were analyzed to affect plant growth, activity and pollutant removal efficiency. Plant type and growth pattern are considered as factors to be considered in selection of appropriate plant types in LID technologies.

CONSTRUCTING DAILY 8KM NDVI DATASET FROM 1982 TO 2000 OVER EURASIA

  • Suzuki Rikie;Kondoh Akihiko
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.18-21
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    • 2005
  • The impact of the interannual climatic variability on the vegetation sensitively appears in the timing of phenological events such as green-up, mature, and senescence. Therefore, an accurate and temporally high-resolution NDVI dataset will be required for analysis on the interannual variability of the climate-vegetation relationship. We constructed a daily 8km NDVI dataset over Eurasia based on the 8km tiled data of Pathfinder A VHRR Land (PAL) Global daily product. Cloud contamination was successfully reduced by Temporal Window Operation (TWO), which is a method to find optimized upper envelop line of the NDVI seasonal change. Based on the daily NDVI time series from 1982 to 2000, an accurate (daily) interannual change of the phenological events will be analyzed.

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The Change of Vegetation Environment since middle-late Holocene in the lower reaches of Taehwa River, Taehwa-dong, Ulsan-si, Korea (울산 태화강 하류 태화동 홀로세 중·후기 식생환경 변화)

  • Kim, HyeRyung;Yoon, Soon-Ock;Hwang, Sangill
    • Journal of The Geomorphological Association of Korea
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    • v.23 no.2
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    • pp.1-13
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    • 2016
  • This study analyzed pollen compositions in archaeological site on alluvial plain of Taehwa River, Taehwa-dong, Ulsan-si vegetational and environmental change during 6,200~3,000 yr BP. The results consist upward of Pollen Zone I (Inner Bay environment), Pollen Zone II (Quercus-Alnus stage) and Pollen Zone III (Alnus stage). The pollen grains of Fagopyrum and reddish gray silty horizon including artifacts of the Bronze Age suggest that there was cultivation on dry-field around the study site, although it is not sure that there was paddy-field cultivation.

A Study on Wind-drift Sand Deposition by Vegetation and Coastal Debris using a Wind Tunnel Test (식생 및 해안표착물에 의한 비사 퇴적 풍동실험 연구)

  • Je, Young Jun;Jeon, Yong Ho;Yoon, Han Sam
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.16 no.3
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    • pp.163-170
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    • 2013
  • The correlation and interaction mechanisms between marine debris and the vegetation zone were studied on the Jinu-do natural beach of the Nakdong river estuary. Laboratory wind tunnel experiments were carried out under the wind-field and bottom-sand conditions using wind tunnel test equipment to investigate the sedimentation characteristics of wind-drift sand deposition around marine debris and the vegetation zone. The major environmental factors/loads considered in this study were the motion of sand by wind on the beach, deposition of marine debris, and change in the vegetation zone/line. When the marine debris was installed in the wind tunnel, deposition at the front of the structure appeared first by wind action, and then deposition developed from behind at 70% of the front ground level. In contrast, in the case of vegetation, the deposition phenomenon appeared first from behind the vegetation zone/line, and was 60% higher than the front. When the height of the debris and vegetation was the same, the required experimental time to bury the vegetation completely was about twice that of the marine debris.