• Title/Summary/Keyword: Vegetation transition

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Consideration of NDVI and Surface Temperature Calculation from Satellite Imagery in Urban Areas: A Case Study for Gumi, Korea

  • Bhang, Kon Joon;Lee, Jin-Duk
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.1
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    • pp.23-30
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    • 2017
  • NDVI (Normalized Difference Vegetation Index) plays an important role in surface land cover classification and LST (Land Surface Temperature Extraction). Its characteristics do not full carry the information of the surface cover typically in urban areas even though it is widely used in analyses in urban areas as well as in vegetation. However, abnormal NDVI values are frequently found in urban areas. We, therefore, examined NDVI values on whether NDVI is appropriate for LST and whether there are considerations in NDVI analysis typically in urban areas because NDVI is strongly related to the surface emissivity calculation. For the study, we observed the influence of the surface settings (i.e., geometric shape and color) on NDVI values in urban area and transition features between three land cover types, vegetation, urban materials, and water. Interestingly, there were many abnormal NDVI values systematically derived by the surface settings and they might influence on NDVI and eventually LST. Also, there were distinguishable transitions based on the mixture of three surface materials. A transition scenario was described that there are three transition types of mixture (urban material-vegetation, urban material-water, and vegetation-water) based on the relationship of NDVI and LST even though they are widely distributed.

Studies of Vegetation Structure Analysis and Vegetation Transition over 25 years of Evergreen Broad-leaved Forest in Hong-Do Island

  • Lee, Sung-Je;Kim, Ji-Tae;Ahn, Young-Hee
    • Journal of Environmental Science International
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    • v.23 no.3
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    • pp.335-357
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    • 2014
  • This study aims at classifying and interpreting on the vegetation structure and the vegetation transition over 25 years (between 1986 and 2010), and the correlation with the change of some conditions (the vegetation height and coverage on each layer and the climate factors as WI, CI, mean annual temperature, mean annual total precipitation etc.) in the Evergreen Broad-Leaved Forest,, Hong-Do island. The EBLF is classified into five units of vegetation (Hedera rhombea-Machilus thunbergii community (M-M comm.), Castanopsis sieboldii forest (Machilus japonica-Castanopsis sieboldii community; Raphiolepis indica var. umbellata-C. sieboldii community), community (Qa comm.), Carpinus turczaninovii community (Ct comm.), Camellia japonica stand (Cj stand)). The vegetation transition by CCA had high correlation with the height and coverage on each layer and the climate factors, and it did the succession (transition) that the M-M comm. (2010) from Mallotus japonicus community Machilus thunbergii community Carpinus coreana community (Cc comm.) Aucuba japonica community (Aj comm.) Trachelos permum asiaticum var. intermedium-Quercus acuta community (TQ comm.) (1986), the communities of C. sieboldii forest (2010) from Aj comm. TQ comm. Raphiolepis umbellata-Camellia japonica community (RC comm.) (1986), the Qa comm. (2010) from Ardisia japonica-Castanopsis sieboldii community (AC comm.) and TQ comm. (1986), the Ct comm. (2010) from Cc comm. RC comm. Aj comm. Quercus serrata community and the Cj stand (2010) from AC comm. (1986). the height and coverage on each layer are also changed.

Study on examination of accuracy of natural environment assessment of satellite data using vegetation index and plant energy

  • Choi, Byung-Yang;Lee, Yang-Jae
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1475-1477
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    • 2003
  • The satellite remote sensing data is good in order to grasp the wide natural environment. The purpose of study is that it examines spectral reflection characteristic and vegetation index by the utilization of the plant energy ( chlorophyll ) for examining the reliability of satellite data and grasps the transition of the natural environment using the result. According to result of analysis, there were NDVI and mutual relationship on chlorophyll, and luminance compensation of NDVI was effective for all area. In vegetation transition, there were no luminance compensation and relation, and there was a decrease of vegetation in area in south and north. The reason was a result by the artificial and natural effect. This analysis is an effective method in order to confirm the change of specific vegetation.

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A Study on Vegetation Index for Zoning of Natural Ecosystem on Baekdudaegan (백두대간 자연생태계의 지역구분을 위한 식생지수에 관한 연구)

  • 김갑태
    • Korean Journal of Environment and Ecology
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    • v.16 no.3
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    • pp.223-232
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    • 2002
  • For the zoning of natural ecosystem, Vegetation Index is calculated from the vegetation data surveyed on Baekdudaegan (Pijae-Doraegijae). Five factors -biodiversity, conservation value of the stand, environmental quality, longevity of the stand, site productivity- are considered in the calculation of Vegetation Index. Vegetation Index might be a useful zoning tool for management of Baekdudaegan. For Vegetation Index I, 59 sample plots 52.2% of total 113 sample plots are belong to core area, 34 sample plots 30.l% and 20 sample plots 17.7% are belong to buffer zone and transition area, respectively. For Vegetation Index II, 49 sample plots 43.4% of total 113 sample plots are belong to core area, 38 sample plots 33.6% and 26 sample plots 23.0% are belong to buffer zone and transition area, respectively.

Variation Characteristics of the Groundwater Level of Natural Vegetation and Sandy Beaches (식생/모래기반 자연해빈에서의 지하수위 변동특성)

  • Park, JungHyun;Yoon, Han-sam
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.19 no.1
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    • pp.62-73
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    • 2016
  • The variation of groundwater by wave, tide and precipitation conditions is closely related to the vegetation environment at the natural vegetation and sandy based beach, and it has a significant impact on the vegetation development and ground stabilization. In this study, the water temperature, electrical conductivity, and pressure were monitored at five observational stations normal to the Jinu-do(Island) shoreline of Nakdong river estuary from March 2012 to September 2014 (approximately 799 days) with the aim of measuring the variation in groundwater-table characteristics. The purpose of the study was to identify factors (tide, wave etc.) affecting groundwater-table variation using time series and correlation analysis, and to record spatial variations in the groundwater level and electrical conductivity as a result of storm events. The observational station in the intertidal zone was strongly affected by wave period and tide level. During the storm period, the groundwater-table and electrical conductivity were stabilized at the edge of sand dunes, vegetation, and areas of transition between freshwater and seawater.

A Study on Vegetation Index for Zoning of Natural Ecosystem on Baekdudaegan -From Namdeogyusan to Sosagogae- (백두대간 자연생태계의 지역구분을 위한 식생지수에 관한 연구 -남덕유산 -소사고개 구간-)

  • 김갑태;엄태원
    • Korean Journal of Environment and Ecology
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    • v.18 no.2
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    • pp.158-166
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    • 2004
  • For the zoning of natural ecosystem, Vegetation Index is calculated from the vegetation data surveyed on Baekdudaegan (from Namdeogyusan to Sosagogae). Five factors-biodiversity, conservation value of the stand, environmental quality, longevity of the stand, site productivity- are considered in the calculation of Vegetation Index. Vegetation Index might be a useful zoning tool for management of Baekdudaegan. For Vegetation Index I, 8 sample plots 12.l% of total 66 sample plots are belong to core area, 21 sample plots 31.8% and 37 sample plots 56.l% are belong to buffer zone and transition area, respectively. For Vegetation Index II, 37 sample plots 41.9% of total 60 sample plots are belong to core area, 19 sample plots 28.8% and 19 sample plots 28.8% are belong to buffer zone and transition area, respectively.

Improvement of the Criteria on Naturalness of the Environmental Conservation Value Assessment Map (ECVAM) (국토환경성평가지도 자연성 평가기준 개선)

  • Song, Wonkyong;Kim, Eunyoung;Jeon, Seong Woo;Park, Sangho;Lee, June
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.2
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    • pp.31-40
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    • 2012
  • The Environmental Conservation Value Assessment Map (ECVAM) is a five grade assessment map created with nationally integrated environmental information and environmental values. The map is made through the evaluation of 65 items, including greenbelt area and naturalness. Naturalness means original state of nature, and it is one of the most important evaluation items for conserving nature. The criteria of naturalness includes the Degree of Green Naturality (DGN) made by MOE. Using the data which has been not updated is a problem of accuracy for ECVAM. Therefore, this study would like to improve the criteria of naturalness. To improve the criteria, the study examined the effectiveness of DGN using field survey. The results of analysis the naturalness without DGN, some area changed grade of naturalness have been already damaged or cleared for agriculture and industrial purposes. The grade of naturalness should be included the concept of vegetation transition like DGN. The study suggested a improved method using vegetation type (natural and planted forest), forest age, and the grade of vegetation conservation. The method was reviewed by experts and field survey. After applying the method in South Korea, the grade of naturalness were distributed evenly like GradeI is 38.87%, GradeII is 37.62%, GradeIII is 23.51%, respectively. From the results of field survey, over 4 grade of forest age in natural forest showed similar pattern of structure and composition in original forests. Therefore, the improved criteria explained the naturalness better than existing criteria, and the accuracy of ECVAM has been improved more.

Characteristics of Wave Attenuation with Coastal Wetland Vegetation (연안 습지식생에 의한 파랑감쇠 특성)

  • Lee, Seong-Dae
    • Journal of Wetlands Research
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    • v.18 no.1
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    • pp.84-93
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    • 2016
  • As a transition region between ocean and land, coastal wetlands are significant ecosystems that maintain water quality, provide natural habitat for a variety of species, and slow down erosion. The energy of coastal waves and storm surges are reduced by vegetation cover, which also helps to maintain wetlands through increased sediment deposition. Wave attenuation by vegetation is a highly dynamic process and its quantification is important for understanding shore protection and modeling coastal hydrodynamics. In this study, laboratory experiments were used to quantify wave attenuation as a function of vegetation type as well as wave conditions. Wave attenuation characteristics were investigated under regular waves for rigid model vegetation. Laboratory hydraulic test and numerical analysis were conducted to investigate regular wave attenuation through emergent vegetation with wave steepness ak and relative water depth kh. The normalized wave attenuation was analyzed to the decay equation of Dalrymple et al.(1984) to determine the vegetation transmission coefficients, damping factor and drag coefficients. It was found that drag coefficient was better correlated to Keulegan-Carpenter number than Reynolds number and that the damping increased as wave steepness increased.

Analysis of Ground Watertable Fluctuation at the Sandy Barrier Island on Jinu-do in Nakdong River Estuary (낙동강 하구역 진우도 자연해빈의 지하수위 변동해석)

  • Park, Jung-Hyun;Yoon, Han-Sam;Lee, In-Cheol
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.4
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    • pp.382-388
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    • 2014
  • This study selected five observational stations in the normal direction of Jinu-do(island) shoreline and observed water temperature, electrical conductivity and pressure from March, 2012 to January, 2013(about 11 months) and attempted to see the variation characteristics of ground watertable. This study wants to know : 1) External environment force factors(tide, climate, wave etc.) affecting ground watertable variation through time series and correlation analysis. 2) Spatial variations of ground watertable and electrical conductivity change by storm event. First, we found that the station at the intertidal zone was strongly affected by wave and tide level and the stations at sand dune and vegetation zone was affected by precipitation and tide level through time series data and correlation analysis. Second, during the storm event, we found that ground watertable and electrical conductivity are stabilized at the start line of sand dune and vegetation zone and transition zone between freshwater layer and seawater layer exists in the experiment area and is about 50~70 m from coastline of the south side of Jinu-do(island).