• 제목/요약/키워드: Remote-sensing index

검색결과 628건 처리시간 0.033초

Monitoring canopy phenology in a deciduous broadleaf forest using the Phenological Eyes Network (PEN)

  • Choi, Jeong-Pil;Kang, Sin-Kyu;Choi, Gwang-Yong;Nasahara, Kenlo Nishda;Motohka, Takeshi;Lim, Jong-Hwan
    • Journal of Ecology and Environment
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    • 제34권2호
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    • pp.149-156
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    • 2011
  • Phenological variables derived from remote sensing are useful in determining the seasonal cycles of ecosystems in a changing climate. Satellite remote sensing imagery is useful for the spatial continuous monitoring of vegetation phenology across broad regions; however, its applications are substantially constrained by atmospheric disturbances such as clouds, dusts, and aerosols. By way of contrast, a tower-based ground remote sensing approach at the canopy level can provide continuous information on canopy phenology at finer spatial and temporal scales, regardless of atmospheric conditions. In this study, a tower-based ground remote sensing system, called the "Phenological Eyes Network (PEN)", which was installed at the Gwangneung Deciduous KoFlux (GDK) flux tower site in Korea was introduced, and daily phenological progressions at the canopy level were assessed using ratios of red, green, and blue (RGB) spectral reflectances obtained by the PEN system. The PEN system at the GDK site consists of an automatic-capturing digital fisheye camera and a hemi-spherical spectroradiometer, and monitors stand canopy phenology on an hourly basis. RGB data analyses conducted between late March and early December in 2009 revealed that the 2G_RB (i.e., 2G - R - B) index was lower than the G/R (i.e., G divided by R) index during the off-growing season, owing to the effects of surface reflectance, including soil and snow effects. The results of comparisons between the daily PEN-obtained RGB ratios and daily moderate-resolution imaging spectroradiometer (MODIS)-driven vegetation indices demonstrate that ground remote sensing data, including the PEN data, can help to improve cloud-contaminated satellite remote sensing imagery.

Remote Sensing Monitoring and Loss Estimated System of Flood Disaster based on GIS

  • Wenqiu, Wei
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.507-515
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    • 2002
  • Remote Sensing Monitoring and Loss Estimated System of Flood Disaster based on GIS is an integrated system comprised flood disaster information receiving and collection, flood disaster simulation, and flood disaster estimation. When the system receives and collects remote sensing monitoring and conventional investigation information, the distributional features of flood disaster on space and time is obtained by means of image processing and information fusion. The economic loss of flood disaster can be classified into two pus: direct economic loss and indirect economic loss. The estimation of direct economic loss applies macroscopic economic analysis methods, i.e. applying Product (Industry and Agriculture Gross Product or Gross Domestic Product - GDP) or Unit Synthetic Economic Loss Index, direct economic loss can be estimated. Estimating indirect economic loss applies reduction coefficient methods with direct economic loss. The system can real-timely ascertains flood disaster and estimates flood Loss, so that the science basis fur decision-making of flood control and relieving disaster may be provided.

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Probabilistic Landslide Susceptibility Analysis and Verification using GIS and Remote Sensing Data at Penang, Malaysia

  • Lee, S.;Choi, J.;Talib, En. Jasmi Ab
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.129-131
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    • 2003
  • The aim of this study is to evaluate the hazard of landslides at Penang, Malaysia, using a Geographic Information System (GIS) and remote sensing. Landslide locations were identified in the study area from interpretation of aerial photographs and field surveys. The topographic and geologic data and satellite image were collected, processed and constructed into a spatial database using GIS and image processing. The used factors that influence landslide occurrence are topographic slope, topographic aspect topographic curv ature and distance from drainage from topographic database, geology and distance from lineament from the geologic database, land use from TM satellite image and vegetation index value from SPOT satellite image. Landslide hazardous area were analysed and mapped using the landslide-occurrence factors by probability - likelihood ratio - method. The results of the analysis were verified using the landslide location data. The validation results showed satisfactory agreement between the hazard map and the existing data on landslide location.

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An initial study on ecological environment changes after emergent water transportation at lower reaches of Tarim River, China based on remote sensing technique

  • Jianli, Zhang;Lin, Li;Longjiang, Du
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.313-315
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    • 2003
  • Tarim River is the longest continental river in China. Its downstream ecological environment declination and valley remedy got great concern. To improve ecological environment of lower Tarim River, “Emergent water transportation project for Tarim river valley remedy” was carried out from May 2000. Water was transported five times till May 2003. Several periods MODIS image was used to monitor water body in river channel. Two periods ETM image was used to interpreter changes of environment. Area of vegetation in 1999 was similar with 2001, but become better in total. The normalized difference vegetation index (NDVI) and vegetative coverage reflected environment changed better.

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지상 원격탐사의 농업적 활용 (Agricultural Application of Ground Remote Sensing)

  • 홍순달;김재정
    • 한국토양비료학회지
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    • 제36권2호
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    • pp.92-103
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    • 2003
  • Research and technological advances in the field of remote sensing have greatly enhanced the ability to detect and quantify physical and biological stresses that affect the productivity of agricultural crops. Reflectance in specific visible and near-infrared regions of the electromagnetic spectrum have proved useful in detection of nutrient deficiencies. Especially crop canopy sensors as a ground remote sensing measure the amount of light reflected from nearby surfaces such as leaf tissue or soil and is in contrast to aircraft or satellite platforms that generate photographs or various types of digital images. Multi-spectral vegetation indices derived from crop canopy reflectance in relatively wide wave band can be used to monitor the growth response of plants in relation to environmental factors. The normalized difference vegetation index (NDVI), where NDVI = (NIR-Red)/(NIR+Red), was originally proposed as a means of estimating green biomass. The basis of this relationship is the strong absorption (low reflectance) of red light by chlorophyll and low absorption (high reflectance and transmittance) in the near infrared (NIR) by green leaves. Thereafter many researchers have proposed the other indices for assessing crop vegetation due to confounding soil background effects in the measurement. The green normalized difference vegetation index (GNDVI), where the green band is substituted for the red band in the NDVI equation, was proved to be more useful for assessing canopy variation in green crop biomass related to nitrogen fertility in soils. Consequently ground remote sensing as a non destructive real-time assessment of nitrogen status in plant was thought to be useful tool for site specific crop nitrogen management providing both spatial and temporal information.

원격탐사자료를 활용한 기상학적 가뭄 시 식생의 생태학적 가뭄 상태 모니터링 (Monitoring the Ecological Drought Condition of Vegetation during Meteorological Drought Using Remote Sensing Data)

  • 원정은;정하은;강신욱;김상단
    • 대한원격탐사학회지
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    • 제38권5_3호
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    • pp.887-899
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    • 2022
  • 기상학적 요인에 의해 발생하는 가뭄은 육상 생태계의 식생에 부정적인 영향을 미친다. 본 연구에서는 기상학적 가뭄이 식생에 영향을 미치는 상태를 식생의 생태가뭄으로 정의하고, 영향 정도를 정량적으로 감시하기 위한 식생의 생태가뭄 상태지수(ecological drought condition index of vegetation, EDCI-veg)를 제안하였다. EDCI-veg는 식생과 기상학적 가뭄 정보 사이의 copula 기반의 이변량 결합확률모델로부터 도출되며, 가뭄이 발생했을 때 현재의 식생 상태가 가뭄으로 인해 얼마나 영향을 받았는지를 수치로 표현할 수 있다. 과거의 기상학적 가뭄 사상과 그에 대응하는 식생 상태를 비교하여 제안된 지수를 살펴본 결과, EDCI-veg는 식생의 생태가뭄을 적절하게 모니터링할 수 있음이 확인되었다. 또한, 원격탐사자료를 활용하여 고해상도의 가뭄 지도를 작성함으로써 생태가뭄 상태를 공간적으로 식별할 수 있었다.

Impact of Vegetation in Reducing Heat Island Phenomenon of Fukuoka City By Applying Remote Sensing Technique

  • Shibata Satoshi;Gotoh Keinosuke;Tachiiri Kaoru
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.541-544
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    • 2004
  • Recently, the heat island phenomenon in which the temperature of a city part rises from the circumference ground has developed into a big problem. In this study, we aimed at examining the impact of increasing vegetation in urban areas to reduce the heat island phenomenon by taking the Fukuoka City of Japan as a case. In order to discuss the relation between vegetation environment and the heat island phenomenon, we have calculated Normalized Difference Vegetation Index (NDVI) and mapped the spatial vegetation distribution. These are then compared with the heat island phenomenon investigations in Fukuoka City. The results of the study revealed that the areas showing comparatively lesser heat island phenomenon are those having increased vegetation.

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

  • Choi, Byung-Yang;Lee, Yang-Jae
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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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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Applicability Assessment of the Expanded Waste Glass Material as Planting Basis Using Ground-Based Remote Sensing

  • Hamamoto, R.;Gotoh, K.;Ikio, D.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.546-548
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    • 2003
  • The expanded waste glass material is one of the recycling materials. We investigated whether the expanded waste glass material is useful as planting basis and effective as heat insulation. We examined the difference of the materials by using vegetation index and temperature. The combination of the improved soils and the improved glasses marked higher vegetation index than other mixture materials. Moreover, this combination material is excellent than other ones to heat insulation. Therefore, it suggests that the expanded waste glass material has high potential to be used as a material for planting basis.

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Land Surface Temperature Dynamics in Response to Changes in Land Cover in An-Najaf Province, Iraq

  • Ebtihal Taki, Al-Khakani;Watheq Fahem, Al-janabi
    • 대한원격탐사학회지
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    • 제39권1호
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    • pp.99-110
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    • 2023
  • Land surface temperature (LST) is a critical environmental indicator affected by land cover (LC) changes. Currently, the most convenient and fastest way to retrieve LST is to use remote sensing images due to their continuous monitoring of the Earth's surface. The work intended to investigate land cover change and temperature response inAn-Najaf province. Landsat multispectral imageries acquired inAugust 1989, 2004, and 2021 were employed to estimate land cover change and LST responses. The findings exhibited an increase in water bodies, built-up areas, plantations, and croplands by 7.78%, 7.27%, 6.98%, 3.24%, and 7.78%, respectively, while bare soil decreased by 25.27% for the period (1989-2021). This indicates a transition from barren lands to different land cover types. The contribution index (CI) was employed to depict how changes in land cover categories altered mean region surface temperatures. The highest LSTs recorded were in bare lands (42.2℃, 44.25℃, and 46.9℃), followed by built-up zones (41.6℃, 43.96℃, and 44.89℃), cropland (30.9℃, 32.96℃, and 34.76℃), plantations (35.4℃, 36.97℃, and 38.92℃), and water bodies (27.3℃, 29.35℃, and 29.68℃) respectively, in 1989, 2004, and 2021. Consequently, these changes resulted in significant variances in LST between different LC types.