• Title/Summary/Keyword: vegetation indices

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National Database, Evaluation and Assessment of Plant species based on the phytosociological Information

  • Kim, Jong-Won;Lee, Eun-Jin
    • Proceedings of the Zoological Society Korea Conference
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    • 1997.10a
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    • pp.42-57
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    • 1997
  • The multicriterion matrix technique (MM-technique) was proposed for a method of monitoring and assessment about vegetation naturalness. Four criteria and 10 subcriteria were selected and two evaluation indices such as VN-value and VN-class were used. The criteria were characterized by syntaxonomical informations of hemeroby concept and potential natural vegetation, hierarchical system between criteria, and ordinal scale of VN-values. VN-values were classified into 11 ordinal levels and condensed to five VN-classes for facilitating practical use. A vegetation map of naturalness described by combination o( two indices was proposed as an alternative resolution of the DGN map. We also discuss the organization of the map content which is a matter of grid size (unit-area). In the case study, a grid size proper to show a full account of real information of actual vegetation is less 250-grid (250 $\times$ 250 $m^2$) in a medium size of city area containing relatively fragmented ecosystems. In conclusion, it was recognized that this new assessment technique was useful and vegetation assessment was accomplished with the smaller grid size in Korea.

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Weighting Coefficient Estimation of Vegetation Health Index for Ecological Drought Analysis (생태가뭄분석을 위한 식생건강지수의 가중치 매개변수 추정)

  • Won, Jeongeun;Choi, Jeonghyeon;Lee, Okjeong;Seo, Jiyu;Kim, Sangdan
    • Journal of Wetlands Research
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    • v.22 no.4
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    • pp.275-285
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    • 2020
  • In this study, after estimating VCI (Vegation Condition Index), TCI (Thermal Condition Index) and VHI (Vegetation Health Index) from the NDVI (Normalized Differentiation Vegetation Index) and LST (Land Surface Temperature) remotely sensed at major sites in Korea during the 2001-1919 period, the correlation between these indices and various drought indices is analyzed for the purpose of assessing the effects of ecological drought. The relative impact of VCI and TCI on vegetation health was found to vary by region. The effects of drought on vegetation in Korea's forest areas could be more clearly identified in TCI than in VCI. It is suggested that the revised VHI, reflecting the relative influence of VCI and TCI, can better explain the effects of drought on vegetation.

Automatic Change Detection of MODIS NDVI using Artificial Neural Networks (신경망을 이용한 MODIS NDVI의 자동화 변화탐지 기법)

  • Jung, Myung-Hee
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.49 no.2
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    • pp.83-89
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    • 2012
  • Natural Vegetation cover, which is very important earth resource, has been significantly altered by humans in some manner. Since this has currently resulted in a significant effect on global climate, various studies on vegetation environment including forest have been performed and the results are utilized in policy decision making. Remotely sensed data can detect, identify and map vegetation cover change based on the analysis of spectral characteristics and thus are vigorously utilized for monitoring vegetation resources. Among various vegetation indices extracted from spectral reponses of remotely sensed data, NDVI is the most popular index which provides a measure of how much photosynthetically active vegetation is present in the scene. In this study, for change detection in vegetation cover, a Multi-layer Perceptron Network (MLPN) as a nonparametric approach has been designed and applied to MODIS/Aqua vegetation indices 16-day L3 global 250m SIN Grid(v005) (MYD13Q1) data. The feature vector for change detection is constructed with the direct NDVI diffenrence at a pixel as well as the differences in some subset of NDVI series data. The research covered 5 years (2006-20110) over Korean peninsular.

Do Physiognomically Designated Protected Areas Match Well with Ecological Data based upon Diversity Indices and Ordination? Implications for Urban Forest Conservation

  • Kee Dae Kim
    • Journal of Environmental Science International
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    • v.32 no.5
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    • pp.329-341
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    • 2023
  • We surveyed the vegetation of an ecological landscape preservation area (legally protected conservation areas or national parks) and the surrounding areas of Mt. Cheonggye, Republic of Korea, to explore the conservation implications for preservation areas and surrounding transition areas. We calculated diversity indices to identify the properties of the preservation and surrounding areas that are relevant to conservation efforts. We then compared the plant community composition between the areas using field and quadrat surveys in the preservation and surrounding areas. The cover of the dominant species in all tree and herb layers was markedly higher in the preservation area than in the peripheral zones. The species richness indices were significantly higher in the preservation area than in the peripheral zones. Ordination using detrended canonical correspondence analyses showed that the cover of the dominant tree species and rocks could explain the distribution of plant species in the Cartesian space of the ordination. Our results demonstrate that physiognomically designated protected areas match well with ecological data based on diversity indices and ordination analyses and that disturbances in the areas surrounding the ecological landscape of preservation areas can have considerable impacts on plant diversity indices. Hence, the preservation and management of surrounding areas are essential conservation elements for protecting the entire ecological landscape of preservation areas.

Vegetation Studies of Girbanr Hills, District Swat, Pakistan (Girbanr Hills의 식생)

  • Hussain, Farrukh;Mohammad Ilyas;Kil, Bong-Seop
    • The Korean Journal of Ecology
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    • v.18 no.2
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    • pp.207-218
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    • 1995
  • Five non-stratified plant communities, Dichanthium-Artemisia-Themeda, Dichanthium- Plectranthes-Themeda, Plectranthes-Carex-Myrine, Heteropogon- Dichanthium-Dodonaea and Artemisia-Cynodon-Ber-beris were recognized in Girbanr hills, District Swat, during autumn, 1992. The indices of similarity showed that the communities were dissimilar. The percentage of leptophyllous and nanophyllous, terophytic and nanophanerophytic species were higher than other groups. These indicate dry and disturben conditions. Due to autumn season most of the species were entering in dormant stage. There was no tree layer on southern slopes while northern slopes had a poor layer of Pinus roxburghii. Deforestation, uprooting, terrace cultivation and overgrazing followed by erosion are the main ecological problems. The presence of isolated trees of Pinus roxburghii and stunted Olea ferruginea indicate that the original vegetation might have been of chirpine or Olea-Pinus type. The area having resource potential can be changed into a forest or rangeland by proper protection and management. Suggestions in favour of improvement are given.

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A Study on Index of Vegetation Surface Roughness using Multiangular Observation

  • Konda, Asako;Kajiwara, Koji;Honda, Yoshiaki
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.673-678
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    • 2002
  • A satellite remote sensing is useful for vegetation monitoring. But it has some problem. One of these, it is difficult to find a difference of vegetation surface roughness using satellite remote sensing. Each vegetation type has unique surface roughness, for example needle leaves forest, broad leaves forest and grassland. Difference of vegetation surface roughness can be detected by satellite multiangular observation. In this study, objective is to propose index of vegetation surface roughness using BRF property. General vegetation indices are calculated from nadir data of satellite data. A proposed index is calculated from two different observation zenith angle data. Two different zenith data can provide BRF (Bi-directional Reflectance Factor) property of satellite observation data. A proposed index was able to detect different value on where NDVI shows similar high value areas of rice field and forest. This index is useful for vegetation monitoring.

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Assessment of Photochemical Reflectance Index Measured at Different Spatial Scales Utilizing Leaf Reflectometer, Field Hyper-Spectrometer, and Multi-spectral Camera with UAV (드론 장착 다중분광 카메라, 소형 필드 초분광계, 휴대용 잎 반사계로부터 관측된 서로 다른 공간규모의 광화학반사지수 평가)

  • Ryu, Jae-Hyun;Oh, Dohyeok;Jang, Seon Woong;Jeong, Hoejeong;Moon, Kyung Hwan;Cho, Jaeil
    • Korean Journal of Remote Sensing
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    • v.34 no.6_1
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    • pp.1055-1066
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    • 2018
  • Vegetation indices on the basis of optical characteristics of vegetation can represent various conditions such as canopy biomass and physiological activity. Those have been mostly developed with the large-scaled applications of multi-band optical sensors on-board satellites. However, the sensitivity of vegetation indices for detecting vegetation features will be different depending on the spatial scales. Therefore, in this study, the investigation of photochemical reflectance index (PRI), known as one of useful vegetation indices for detecting photosynthetic ability and vegetation stress, under the three spatial scales was conducted using multi-spectral camera installed in unmanned aerial vehicle (UAV),field spectrometer, and leaf reflectometer. In the leaf scale, diurnal PRI had minimum values at different local-time according to the compass direction of leaf face. It meant that each leaf in some moment had the different degree of light use efficiency (LUE). In early growth stage of crop, $PRI_{leaf}$ was higher than $PRI_{stands}$ and $PRI_{canopy}$ because the leaf scale is completely not governed by the vegetation cover fraction.In the stands and canopy scales, PRI showed a large spatial variability unlike normalized difference vegetation index (NDVI). However, the bias for the relationship between $PRI_{stands}$ and $PRI_{canopy}$ is lower than that in $NDVI_{stands}$ and $NDVI_{canopy}$. Our results will help to understand and utilize PRIs observed at different spatial scales.

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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Selection of Optimal Vegetation Indices for Predicting Winter Crop Dry Matter Based on Unmanned Aerial Vehicle (무인기 기반 동계 사료작물의 건물수량 예측을 위한 최적 식생지수 선정)

  • Shin, Jae-Young;Lee, Jun-Min;Yang, Seung-Hak;Lim, Kyoung-Jae;Lee, Hyo-Jin
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.40 no.4
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    • pp.196-202
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    • 2020
  • Rye, whole-crop barley and Italian Ryegrass are major winter forage species in Korea, and yield monitoring of winter forage species is important to improve forage productivity by precision management of forage. Forage monitoring using Unmanned Aerial Vehicle (UAV) has offered cost effective and real-time applications for site-specific data collection. To monitor forage crop by multispectral camera with UAV, we tested four types of vegetation index (Normalized Difference Vegetation Index; NDVI, Green Normalized Difference Vegetation Index; GNDVI, Normalized Green Red Difference Index; NGRDI and Normalized Difference Red Edge Index; NDREI). Field measurements were conducted on paddy field at Naju City, Jeollanam-do, Korea between February to April 2019. Aerial photos were obtained by an UAV system and NDVI, GNDVI, NGRDI and NDREI were calculated from aerial photos. About rye, whole-crop barley and Italian Ryegrass, regression analysis showed that the correlation coefficients between dry matter and NDVI were 0.91~0.92, GNDVI were 0.92~0.94, NGRDI were 0.71~0.85 and NDREI were 0.84~0.91. Therefore, GNDVI were the best effective vegetation index to predict dry matter of rye, wholecrop barley and Italian Ryegrass by UAV system.

Analysis of Relationship between Vegetation Indices and Crop Yield using KOMPSAT (KOreaMulti-Purpose SATellite)-2 Imagery and Field Investigation Data (KOMPSAT-2 위성영상과 현장 측정자료를 통한 식생지수와 수확량의 상관관계 분석)

  • Lee, Ji-Wan;Park, Geun-Ae;Joh, Hyung-Kyung;Lee, Kyo-Ho;Na, Sang-Il;Park, Jong-Hwa;Kim, Seong-Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.53 no.3
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    • pp.75-82
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    • 2011
  • This study refers to the derivation of simple crop yield prediction equation by using KOMPSAT-2 derived vegetation index. For a 1.25 ha small farm area located in the middle part of South Korea, the KOMPSAT-2 panchromatic and multi-spectral images of 31th August 2008, 17th November 2008, and 10th September 2009 were used. The field spectral reflectance during growing period for the 6 crops (rice, potato, corn, red pepper, garlic, and bean) were measured using ground spectroradiometer and the yield was investigated. Among the 6 vegetation indices (VI), the NDVI and ARVI between measured and image derived showed high relationship with the coefficient of determination of 0.85 and 0.95 respectively. Using the 3 years field data, the NDVI and ARVI regression curves were derived, and the yields were tried to compare with the maximum VIs value.