• Title/Summary/Keyword: Vegetation cover

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Application of Vegetation Indices for Forest Degradation Using Landsat TM Data

  • Kim, Choen;Joung, Khang-Ho
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.192-197
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    • 1998
  • This paper demonstrates that it is feasible to evaluate forest degradation and to detect deforestation in the 8156$km^2$ study area affected by expand farming using vegetation indices derived from Landsat TM data. The NDVI-growing stock relation was applied on th Landsat TM data and a 3 second grid DEM, whose coverages could improve the assessment of forest degradation and also estimate the rate of change of forest cover area depending on elevation intervals. The strength of the relationship between the ratio of the greenness and brightness indices and forest degradation conditions would have been more interesting in the deforested areas which were converted to crop farming land.

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Effects of Shortwave Infrared Bands of ASTER and ETM+ for Assessing Vegetative Information

  • Lee, Kyu-Sung;Jang, Ki-Chang;Kim, Sun-Hwa;Park, Yoon-Il;Ryu, Joung-Mi
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1027-1029
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    • 2003
  • The primary uses of SWIR bands of ASTER data are to analyze geological features. In this study, we are attempting to evaluate the effect of using the narrow band A STER data for extracting information related to biophysical information of forest vegetation. ASTER and ETM+ data have been obtained simultaneously over the study area in Kyongan-River basin on May 8, 2003. Two data sets were initially processed to reduce atmospheric effects and converted to percent reflectance values, which make them comparable each other. ASTER and ETM+ reflectance were then analyzed by using the field survey data that include forest leaf area index (LAI), cover types, species composition, and stand density. Preliminary results show that ASTER reflectance were not much different to ETM+ reflectance to explain LAI.

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Multi-temporal image derived Ratio Vegetation Index and NDVI in a landslide prone region

  • Paramarthalingam, Rajakumar;Shanmugam, Sanjeevi
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.257-259
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    • 2003
  • Landuse maps are prepared from satellite imagery and field observations were conducted at various locations in the study area. Compared to the field data and NDVI and RVI thematic maps, NDVI is better than RVI, because it compensates for changing illumination conditions, surface slope, aspect and other factors. Clouds, water and snow have negative values for RVI and NDVI. Rock and bare soils have similar reflectance in both NIR and visible band, so RVI and NDVI are near zero. In forest areas with good vegetation cover, NDVI is high and landslide occurrence is less. But if annual and biennial vegetations are present and if cultivation practices are changed frequently, NDVI is medium and landslide occurrence is moderate. In areas where deforestation and settlement is in progress, NDVI is less and landslide occurrence is more. The NDVI FCC thematic map may be used as an important layer in GIS application for landslide studies. Analyzing other layers such as slope, rainfall, soil, geology, drainage, lineament, etc with NDVI FCC layer will give a better idea about the identity of landslide prone areas.

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Relationships Between Ecological and Utilizational Effectiveness of Green Roof Sites (옥상녹화지의 생태적 효과와 이용 효과의 상관성)

  • Kim, Hyun;Lee, Gwan-Gyu
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.2
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    • pp.114-122
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    • 2008
  • Roof greening recently emerged to be an important issue of environmental policies in a city. To cover roofs of buildings with green vegetation gives chances not only to improve urban environmental function but also provides the opportunities of environmental learning and convenience for users in the building. This study aimed to give directions for roof greening plan to designers by acknowledging the relationships between ecological and utilizational effectiveness. 10 sites and 15 variables were adopted to measure the relationships. As a result, no positive correlations was found between them. One of the results in correlation analysis among variables, however, showed that the roof gardens have high utilizational effectiveness only when a green roof was made by focusing on ecological functions in addition to the concepts that will guarantee user's convenience such as accessibility, entrance and exit, facilities for convenience and learning. The results implies that a green roof has to be designed considering multi-functional effects. Correlation between species of vegetation and the number of daily users, average staying hours, and attending level for environment educational programs were not significant. These findings imply that when a green roof has to be take high utilizational effectiveness, both plentiful vegetation species and design concepts for users' convenience are should be considered.

Analysis of Spring Drought Using NOAA/AVHRR NDVI for North Korea (NOAA/AVHRR NDVI를 이용한 북한지역 봄 가뭄 분석)

  • Jang, Min-Won;Yoo, Seung-Hwan;Choi, Jin-Yong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.6
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    • pp.21-33
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    • 2007
  • Different vegetation indices from satellite images have been used for monitoring drought damages, and this study aimed to develop a drought index using NOAA/AVHRR NDVI(Normalized Difference Vegetation Index) and to analyze the temporal and spatial distribution of spring drought severity in North Korea from 1998 to 2001. A new drought index, DevNDVI(Deviation of NDVI), was defined as the difference between a monthly NDVI and average monthly NDVI at the same cover area, and the DevNDVI images at all years except for 2001 demonstrated the drought-damaged areas referred from various domestic and foreign publications. The vegetation of 2001 showed high vitality despite the least amount of rainfall among the target years, and the reason was investigated that higher temperature above normal average would shift the growing stages of plants ahead. Therefore, complementary methods like plant growth models or ground survey data should be adopted in order to evaluate drought-induced plant stress using satellite-based NDVI and to make up far the distortion induced by other environments than lack of precipitation.

Application of Remote Sensing and GIS to the evaluation of riparian buffer zones

  • Ha, Sung-Ryong;Lee, Seung-Chul;Ko, Chang-Hwan;Seo, Se-Deok;Jo, Yun-Won
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.436-440
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    • 2006
  • Diffuse pollution has been considering as a major source of the quality deterioration of water resources. The establishment of riparian vegetation strips of buffers along those areas of water bodies is used to reduce the threat of diffuse pollution. Remote sensing offers a means by which critical areas could be identified, so that subsequent action toward the establishment of riparian zones can be taken. Even though the principal purpose of this research comes from the feasibility of the imagery of KOMPSAT-2 satellite, Landsat TM satellite data, which has 7 bands, are used to characterize the land cover for the study area on the behalf of KOMPSAT-2. This investigation focuses on the assessment of the existing riparian buffer zones for a portion of the upper Geum river watershed from the viewpoint of pollution mitigation by riparian vegetation strip establishment. Through comparing the delineation of riparian buffer zones developed with the existing zones established by the government, we can find the critical distortion points of the existing riparian buffer zone.

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Analyses and trends of forest biomass in higher Northern Latitudes

  • Tsolmon, R.;Tateishi, R.;Sambuu, B.;Tsogtbayar, Sh.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.965-967
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    • 2003
  • Information on forest volume, forest coverage and biomass are important for developing global perspectives about CO$_{2}$ concentration changes. Forest biomass cannot be directly measured from space yet, but remotely sensed greenness can be used to estimate biomass on decadal and longer time scales in regions of distinct seasonality, as in the north. Hence, in this research, numerical methods were used to estimate forest biomass in higher northern regions. A regression model linking Normalized Difference Vegetation Index(NDVI), to forest biomass extracted from SPOT/4 VEGETATION data and PAL 8km data in regional and continental area (N40-N70) respectively. Statistical tests indicated that the regression model can be used to represent the changes of forest biomass carbon pools and sinks at high latitude regions over years 1982-2000. This study suggests that the implementation of estimation of biomass based on 8-km resolution NOAA/AVHRR PAL and SPOT-4/VEGETATION data could be detected over a range of land cover change processes of interest for global biomass change studies.

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Remote Sensing Application for the Mineralized Zone Using Landsat TM Data (LANSAT TM자료에 의한 광화대조사 응용기법개발)

  • 姜必鍾;智光薰;曺民肇;崔映燮;Choi, Young Sup
    • Korean Journal of Remote Sensing
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    • v.2 no.2
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    • pp.79-94
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    • 1986
  • TM data, which have better resolution in spatial and spectral than MSS data, were used for this study, and several Image Processing Techniques (IPT) were examined for finding the best IPT to fit to lineament extraction and mineralized zone mapping. The Ryeongnam area was selected as test area, because the area is one of major mineralized zones in Korea and its hydrothermal alteration zone is wider and deeper than other areas. The spatial filtering method is most optimum one for limeament extraction: that is, the directional spatial filtering is most efficient to detect N-S, E-W direction lineaments on the image, and the high boost filtering can be applied for mapping all direction lineaments. The ratio method was selected for detecting altered zone. It is possible to make several tens combinations in ratio with 7 bands of TM data, but considering spectral characteristics of each band of TM to the geological meterials and vegetation, the band 4/band 3(A), band 5/band 7(B), and B/A ratio methods were chosen among them. The 5/7 ratio image did not show clearly the altered area due to noise from vegetation cover, so the 4/3 ratio imae was used for trying to decrease the effect of vegetation. As a result the B/A ratio image showed quite nicely the altered zone of the test area. In conclusion, the spatial filtering is the best image processing techniques for lineament mapping, and the B/A ratio image in TM data is useful for the mineralized zone mapping.

Selection of factors to be monitored for vegetation according to land cover type (토지피복 유형에 따른 식생 감시대상 인자의 선정)

  • Haeun Jung;Chaelim Lee;Jeonghoon Lee;Sangdan Kim
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.329-329
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    • 2023
  • 가뭄은 수개월에서 수년에 걸쳐 평년보다 낮은 강수량을 특징으로 하는 극심한 기후 현상으로 크게 기상학적 가뭄과 식생 가뭄 또는 농업 가뭄, 수문학적 가뭄, 사회경제적 가뭄으로 구분할 수 있다. 본 연구에 사용된 기상학적 가뭄지수는 표준강수지수 (Standardized Precipitation Index), 증발수요가뭄지수 (Evaporative Demand Drought Index), 표준강수증발산지수 (Standardized Precipitation Evapotranspiration Index), Copula 기반 결합가뭄지수 (Copula-based Joint Drought Index)이다. 식생지수는 0부터 1까지 0.05 간격으로 가중치를 적용하여 21개의 식생건강지수(Vegetation Health Index)를 사용하였다. VHI는 널리 사용되고 있는 원격탐사자료 기반의 가뭄지수이며, 이는 식생상태지수 (Vegetation Condition Index)와 열상태지수 (Thermal condition index)의 선형 결합으로 이루어진다. 기상학적 가뭄지수와 식생지수 사이의 상호의존도 및 민감도를 분석하기 위해 상관성 분석을 수행하였으며, 이를 토지피복 유형 (시가화 건조지역, 농업지역, 초지, 산림지역)에 따른 분석도 수행하고자 하였다.

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Changes in Vegetation Characteristics Over Time in the Isolated Forests of the Urban Areas: A Case Study on the Mt. Hwangyeong, Busan Metropolitan City (도시 내 고립된 임지의 경시적 식생특성 변화: 부산광역시 황령산을 사례로)

  • Cho, Jae Hyong;Park, Chan Ryul;Oh, Jeong Hak;Kim, Jun Soo;Cho, Hyun Je
    • Journal of Korean Society of Forest Science
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    • v.105 no.3
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    • pp.284-293
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    • 2016
  • In order to assess th changes in vegetation characteristics over time in the forest-lands which is isolated by urbanization, vegetation surveys based on the Braun-Blanquet phytosociological method was carried out in 1996 and 2015 on Mt. Hwangyeong located in the center of Busan metropolitan city, South Korea. The number of vegetation types based on floristic composition showed no significant changes, the vegetation units under the community levels was more or less represents the difference. the average total vegetation cover and average number of species per unit area ($100m^2$) was increased 16% and 2 species, respectively. The relative importance value (RIV) for each tree species, Quercus spp. like as Q. mongolica and Q. serrata was decreased, while the warmth-tolerant trees, evergreen broad-leaved trees, and mesophyte like Lindera erythrocarpa, Styrax japonica, Osmanthus heterophyllus, and Stephanandra incisa was increased significantly. Changes of the life form spectrums of vascular plants did not substantially, hemicryptophyte(H) and therophyte (Th) was decreased, while nanophanerophyte(N) was increased significantly. Also through the creating of large-scale vegetation map (based on physiognomic vegetation types) was compared the spatial distribution characteristics of each vegetation types.