• Title/Summary/Keyword: Vegetation information

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A Long-term Variability of the Extent of East Asian Desert (동아시아 사막 면적의 경년변화분석)

  • Han, Hyeon-Gyeong;Lee, Eunkyung;Son, Sanghun;Choi, Sungwon;Lee, Kyeong-Sang;Seo, Minji;Jin, Donghyun;Kim, Honghee;Kwon, Chaeyoung;Lee, Darae;Han, Kyung-Soo
    • Korean Journal of Remote Sensing
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    • v.34 no.6_1
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    • pp.869-877
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    • 2018
  • The area of desert in East Asia is increasing every year, and it cause a great cost of social damage. Because desert is widely distributed and it is difficult to approach people, remote sensing using satellites is commonly used. But the study of desert area comparison is insufficient which is calculated by satellite sensor. It is important to recognize the characteristics of the desert area data that are calculated for each sensor because the desert area calculated according to the selection of the sensor may be different and may affect the climate prediction and desertification prevention measures. In this study, the desert area of Northeast Asia in 2001-2013 was calculated and compared using Moderate Resolution Imaging Spectroradiometer (MODIS) and Vegetation. As a result of the comparison, the desert area of Vegetation increased by $3,020km^2/year$, while in the case of MODIS, it decreased by $20,911km^2/year$. We performed indirect validation because It is difficult to obtain actual data. We analyzed the correlation with the occurrence frequency of Asian dust affected by desert area change. As a result, MODIS showed a relatively low correlation with R = 0.2071 and Vegetation had a relatively high correlation with R = 0.4837. It is considered that Vegetation performed more accurate desert area calculation in Northeast Asian desert area.

Biomass Estimation of Gwangneung Catchment Area with Landsat ETM+ Image

  • Chun, Jung Hwa;Lim, Jong-Hwan;Lee, Don Koo
    • Journal of Korean Society of Forest Science
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    • v.96 no.5
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    • pp.591-601
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    • 2007
  • Spatial information on forest biomass is an important factor to evaluate the capability of forest as a carbon sequestrator and is a core independent variable required to drive models which describe ecological processes such as carbon budget, hydrological budget, and energy flow. The objective of this study is to understand the relationship between satellite image and field data, and to quantitatively estimate and map the spatial distribution of forest biomass. Landsat Enhanced Thematic Mapper (ETM+) derived vegetation indices and field survey data were applied to estimate the biomass distribution of mountainous forest located in Gwangneung Experimental Forest (230 ha). Field survey data collected from the ground plots were used as the dependent variable, forest biomass, while satellite image reflectance data (Band 1~5 and Band 7), Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), and RVI (Ratio Vegetation Index) were used as the independent variables. The mean and total biomass of Gwangneung catchment area were estimated to be about 229.5 ton/ha and $52.8{\times}10^3$ tons respectively. Regression analysis revealed significant relationships between the measured biomass and Landsat derived variables in both of deciduous forest ($R^2=0.76$, P < 0.05) and coniferous forest ($R^2=0.75$, P < 0.05). However, there still exist many uncertainties in the estimation of forest ecosystem parameters based on vegetation remote sensing. Developing remote sensing techniques with adequate filed survey data over a long period are expected to increase the estimation accuracy of spatial information of the forest ecosystem.

Effect of Vegetation Layers on Soil Moisture Measurement Using Radars (레이다를 이용한 토양 수분함유량 측정에서 초목 층의 영향 분석)

  • Park, Sinmyong;Oh, Yisok
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.7
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    • pp.660-663
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    • 2016
  • This paper presents the effect of vegetation layer and radar parameters on soil moisture measurement using the vegetation layer scattering model and surface scattering model. The database of backscattering coefficients for various vegetation layer densities, incidence angles, frequencies, and polarizations is generated using $1^{st}$-order RTM(Radiative Transfer Model). Then, surface soil moisture contents were estimated from the backscattering coefficients in the database using the WCM(Water Cloud Model) and Oh model. The retrieved soil moisture contents were compared with the soil moisture contents in the input parameters of the RTM to estimate the retrieval errors. The effects of vegetation layer and radar parameters on soil moisture measurement are analyzed using the retrieval errors.

Time series Analysis of Land Cover Change and Surface Temperature in Tuul-Basin, Mongolia Using Landsat Satellite Image (Landsat 위성영상을 이용한 몽골 Tuul-Basin 지역의 토지피복변화 및 지표온도 시계열적 분석)

  • Erdenesumbee, Suld;Cho, Gi Sung
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.3
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    • pp.39-47
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    • 2016
  • In this study analysis the status of land cover change and land degradation of Tuul-Basin in Mongolia by using the Landsat satellite images that was taken in year of 1990, 2001 and 2011 respectively in the summer at the time of great growth of green plants. Analysis of the land cover change during time series data in Tuul-Basin, Mongolia and NDVI (Normalized Difference Vegetation Index), SAVI (Soil-Adjusted Vegetation Index) and LST (Land Surface Temperature) algorithm are used respectively. As a result shows, there was a decrease of forest and green area and increase of dry and fallow land in the study area. It was be considered as trends to be a land degradation. In addition, there was high correlation between LST and vegetation index. The land cover change or vitality of vegetation which is taken in study area can be closely related to the temperature of the surface.

RGB Composite Technique for Post Wildfire Vegetation Monitoring Using Sentinel-2 Satellite Data (산불 후 식생 회복 모니터링을 위한 Sentinel-2 위성영상의 RGB 합성기술)

  • Kim, Sang-il;Ahn, Do-seob;Kim, Seung-chul
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.939-946
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    • 2021
  • Monitoring of post wildfire provides important information for vegetation restoration. In particular, remote sensing data are known to provide useful information necessary for monitoring. However, there are insufficient research results which is monitoring the vegetation recovery using remote sensing data. This study is directed to monitoring post-wildfire vegetation restoration. It proposes a method for monitoring vegetation restoration using Sentinel-2 satellite data by compositing Tasseled Cap linear regression trend in a post wildfire study sites. Although it is a simple visualization technique using satellite images, it was able to confirm the possibility of effective monitoring.

Satellite-based Hybrid Drought Assessment using Vegetation Drought Response Index in South Korea (VegDRI-SKorea) (식생가뭄반응지수 (VegDRI)를 활용한 위성영상 기반 가뭄 평가)

  • Nam, Won-Ho;Tadesse, Tsegaye;Wardlow, Brian D.;Jang, Min-Won;Hong, Suk-Young
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.4
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    • pp.1-9
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    • 2015
  • The development of drought index that provides detailed-spatial-resolution drought information is essential for improving drought planning and preparedness. The objective of this study was to develop the concept of using satellite-based hybrid drought index called the Vegetation Drought Response Index in South Korea (VegDRI-SKorea) that could improve spatial resolution for monitoring local and regional drought. The VegDRI-SKorea was developed using the Classification And Regression Trees (CART) algorithm based on remote sensing data such as Normalized Difference Vegetation Index (NDVI) from MODIS satellite images, climate drought indices such as Self Calibrating Palmer Drought Severity Index (SC-PDSI) and Standardized Precipitation Index (SPI), and the biophysical data such as land cover, eco region, and soil available water capacity. A case study has been done for the 2012 drought to evaluate the VegDRI-SKorea model for South Korea. The VegDRI-SKorea represented the drought areas from the end of May and to the severe drought at the end of June. Results show that the integration of satellite imageries and various associated data allows us to get improved both spatially and temporally drought information using a data mining technique and get better understanding of drought condition. In addition, VegDRI-SKorea is expected to contribute to monitor the current drought condition for evaluating local and regional drought risk assessment and assisting drought-related decision making.

Analysis of the Possibility for Practical Use of MSI/ MidIR/ II Vegetation Indices for Drought Detection of Spring Season (MSI/ MidIR/ II 식생지수를 이용한 봄 가뭄탐지 활용 가능성 분석)

  • Kim, Sung-Jae;Choi, Kyung-Sook;Chang, Eun-Mi;Hong, Seong-Wook
    • Spatial Information Research
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    • v.19 no.5
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    • pp.37-46
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    • 2011
  • In recent years, utilizations of satellite imagery have been extensively conducted in order to obtain accurate information on drought detection in spring season. This research also carried out utilization of satellite imagery through the various vegetation indices such as NDVI(Normalized Difference Vegeation Index), MSI(Moisture Stress Index), MidIR Index, II(Infrared Index) to find better methodology to detect drought phenomena, especially occurring in spring season. For this purpose, Landsat TM(Thematic Mapper) images were used and applied on the Yeong-cheon city. In this study, the characteristics of DN(Digital Number) for each vegetation index is analyzed, and the correlation analysis between indices and DN according to the number of days with no rain is performed. The results shows high correlation between NDVI and MSI and II with positive correlation on MSI, and negative correlation on II. This indicates the possibility for practical use of MSI, II indices with NDVI to obtain better credibility for detecting spring droughts.

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.