• 제목/요약/키워드: Vegetation change

검색결과 864건 처리시간 0.03초

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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Assessing Stream Vegetation Dynamics and Revetment Impact Using Time-Series RGB UAV Images and ResNeXt101 CNNs

  • Seung-Hwan Go;Kyeong-Soo Jeong;Jong-Hwa Park
    • 대한원격탐사학회지
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    • 제40권1호
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    • pp.9-18
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    • 2024
  • Small streams, despite their rich ecosystems, face challenges in vegetation assessment due to the limitations of traditional, time-consuming methods. This study presents a groundbreaking approach, combining unmanned aerial vehicles(UAVs), convolutional neural networks(CNNs), and the vegetation differential vegetation index (VDVI), to revolutionize both assessment and management of stream vegetation. Focusing on Idong Stream in South Korea (2.7 km long, 2.34 km2 basin area)with eight diverse revetment methods, we leveraged high-resolution RGB images captured by UAVs across five dates (July-December). These images trained a ResNeXt101 CNN model, achieving an impressive 89% accuracy in classifying vegetation cover(soil,water, and vegetation). This enabled detailed spatial and temporal analysis of vegetation distribution. Further, VDVI calculations on classified vegetation areas allowed assessment of vegetation vitality. Our key findings showcase the power of this approach:(a) TheCNN model generated highly accurate cover maps, facilitating precise monitoring of vegetation changes overtime and space. (b) August displayed the highest average VDVI(0.24), indicating peak vegetation growth crucial for stabilizing streambanks and resisting flow. (c) Different revetment methods impacted vegetation vitality. Fieldstone sections exhibited initial high vitality followed by decline due to leaf browning. Block-type sections and the control group showed a gradual decline after peak growth. Interestingly, the "H environment block" exhibited minimal change, suggesting potential benefits for specific ecological functions.(d) Despite initial differences, all sections converged in vegetation distribution trends after 15 years due to the influence of surrounding vegetation. This study demonstrates the immense potential of UAV-based remote sensing and CNNs for revolutionizing small-stream vegetation assessment and management. By providing high-resolution, temporally detailed data, this approach offers distinct advantages over traditional methods, ultimately benefiting both the environment and surrounding communities through informed decision-making for improved stream health and ecological conservation.

산림식생유형에 따른 조류 종다양성 분석 (Bird Species Diversity Analysis According to the Type of Forest Vegetation)

  • 박인환;김유훈;조광진
    • 한국환경복원기술학회지
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    • 제15권6호
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    • pp.43-52
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    • 2012
  • For this paper, a study targeting 9 forest patches in Dangjin to suggest for the wild birds, was conducted. The correlation between the emergence of wild birds and the forest vegetation was analyzed, and the patterns of forest vegetation for the improvement of species diversity were suggested by classifying wild birds and foraging guild by the type of forest vegetation. As for the characteristics of the wild birds emerged, more species and bigger population appeared in the vegetation type of mixed stand forest where the natural deciduous broadleaf trees and evergreen needleleaf trees coexisted in the large scale vegetation area. Thus, it was known that the advent of summer migratory birds and resident birds were affected the most by forest patches and vegetation types. As for foraging guild, the larger the forest paches the more the species and the population of the wild birds inhabiting in shrubs and bushes.

Analysis of Some Desert Ecosystems Vegetation in Abu Dhabi Emirate, United Arab Emirates. Effect of Land Use

  • Mousa, Mohamed Taher;Ksiksi, Taoufik Salah
    • Journal of Forest and Environmental Science
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    • 제25권1호
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    • pp.49-55
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    • 2009
  • The present study analyses the effect of land use on the vegetation of some desert ecosystems in Abu Dhabi, United Arab Emirates (UAE). Three sites were selected to represent different types of land use, inside Umm Al-Banadeq forest, outside the forest and along Abu Dhabi-Al Ain Trucks Road. In total, fifty-two stands were examined; including a matrix of 14 species ${\times}$ 52 stands. Based on species cover data, stands were classified using TWINSPAN and ordinated using DCA. Four vegetation groups were generated at level three of classification. Zygophyllum mandavillei was dominant in most vegetation groups; Heliotropium bacciferum dominated vegetation groups inhabited the forest. Species richness, species turnover, relative evenness and relative concentration of dominance of forest vegetation groups were 2.8, 5.7, 0.7, and 2.0, respectively. The differences were attributed to both natural variability and forestry-induced changes, including change in land use, drainage and ploughing and shading by trees. Vegetation group inhabited Abu Dhabi-Al Ain Trucks Road, that were dominated by Haloxylon salicornicum and Zygophyllum mandavillei have high total cover (8.8 m per $m^{-1}$). Most community and vegetation attributes were significantly higher inside the forest than outside. Human interventions and environmental factors affected species diversity and abundance of these communities.

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지하수위와 연계된 습지 식생의 비선형 동역학 (Non-linear dynamics of wetland vegetation induced by groundwater table)

  • 이옥정;김상단
    • 한국습지학회지
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    • 제21권2호
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    • pp.132-139
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    • 2019
  • 식생과 지하수위 사이의 양방향 상호 작용은 습지 식생의 동역학에 많은 영향을 미친다. 본 연구에서는 지하수위에 의해 영향을 받는 습지 식생의 비선형 동역학이 분석된다. 지하수위에 대한 영향은 습지 식생의 지배방정식에서 손실 항으로 설명되며, 지하수위 변화에 따라서 습지 식생이 어떻게 서로 다른 두 개의 안정적인 상태로 수렴될 가능성이 있게 되는지를 살펴보게 된다. 이러한 개념적 접근법으로부터 지하수위 변화에 따라 현재 습지에 존재하는 식생이 소멸되어 다른 식생 종으로 안정화되는 대변환에 대한 취약성이 분석된다.

함평만 무안 지역 갯벌의 식생 및 비식생 환경에서 이산화탄소 농도와 플럭스의 계절 변동 (Seasonal variations of CO2 concentration and flux in vegetation and non-vegetation environments on the Muan tidal flat of Hampyong Bay)

  • 소윤환;강동환;권병혁;김박사
    • 한국습지학회지
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    • 제21권4호
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    • pp.257-266
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    • 2019
  • 본 연구에서는 함평만에 속하는 무안 지역의 갯벌에서 갈대가 서식하는 식생 지역과 갈대가 없는 비식생 지역을 6개 지점씩 선정하여 저조시에 계절별로 이산화탄소 농도와 플럭스 및 지온의 변화를 관측하였다. 관측은 2012년 5월 30일(봄)과 8월 8일(여름), 2013년 1월 31일(겨울)에 각각 수행되었다. 관측 결과, 식생 지역의 이산화탄소 평균농도는 전체적으로 겨울에 가장 높았고 봄, 여름 순으로 나타났으며, 비식생 지역도 식생 지역과 같은 농도변화를 보였다. 식생 지역의 이산화탄소 플럭스는 봄과 여름에 모두 양(+)의 값으로 방출(emission)의 형태를 보이나, 겨울에는 반대로 흡수(uptake)하는 음(-)의 값으로 나타났다. 이산화탄소 플럭스의 평균값은 봄이 가장 높았으나 여름과 거의 유사하였고, 겨울은 낮은 음의 값으로 나타났다. 비식생 지역은 봄에 양의 값으로 방출의 형태를 보였고, 여름과 겨울에는 흡수하는 음의 값으로 나타났다. 평균값은 봄이 가장 높았고, 여름과 겨울의 차는 작게 나타났다. 연구지역 이산화탄소 플럭스의 계절적인 변화특성은 봄의 경우 식생과 비식생 지역 모두 호흡에 의한 방출이 우세하였으며, 여름은 식생 지역에서 방출이 우세하였고 비식생 지역은 식물플랑크톤의 광합성에 의한 흡수가 확인되었으나 매우 미미하였다. 겨울은 식생 지역에서 이산화탄소 플럭스의 변화가 거의 나타나지 않았으며, 비식생 지역은 흡수가 일부 확인되었으나 매우 미미하였다.

월출산 국립공원 추이대 군락의 수직적 분포를 통해 본 지구 온난화의 영향과 금후의 천이 가능성 (Influences of Global Warming and Succession Possibility through Vertical Distribution of Communities in Ecotone, Wolchulsan National Park)

  • 이성제;안영희
    • 한국환경과학회지
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    • 제20권12호
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    • pp.1561-1584
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    • 2011
  • This study aims at classifying and interpreting on the vegetation structure and analyzing the correlationship between communities and environmental conditions in Mt. Wolchulsan. We also predicted the succession possibility and the vertical distribution change of vegetations according to the global warming, through the pioneer species of a forest change and dominant species of canopy vegetations. We also analyzed the Raunkiaer's life-form. The communities in this ecotone are distributed vertically in the order of a Quercus acuta community, a Q. serrata-Q. variabilis community and a Q. serrata community. A Pinus densiflora community appears on the most of altitudes. The distribution of communities correlates highly with an altitude. The Q. serrata-Q. variabilis community will be succession to the Q. acuta community, and the Q. variabilis will be under natural selection gradually or remain locally. The Q. serrata community will possibly maintain as it is, and the P. densiflora community will be also under natural selection gradually. The valuable quantitative and numerical life-forms are confirmed and the layer structure of present vegetation will not be changed.

NDVI time series analysis over central China and Mongolia

  • Park, Youn-Young;Lee, Ga-Lam;Yeom, Jong-Min;Lee, Chang-Suk;Han, Kyung-Soo
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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    • pp.224-227
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    • 2008
  • Land cover and its changes, affecting multiple aspects of the environmental system such as energy balance, biogeochemical cycles, hydrological cycles and the climate system, are regarded as critical elements in global change studies. Especially in arid and semiarid regions, the observation of ecosystem that is sensitive to climate change can improve an understanding of the relationships between climate and ecosystem dynamics. The purpose of this research is analyzing the ecosystem surrounding the Gobi desert in North Asia quantitatively as well as qualitatively more concretely. We used Normalized Difference Vegetation Index (NDVI) derived from SPOT-VEGETATION (VGT) sensor during 1999${\sim}$2007. Ecosystem monitoring of this area is necessary because it is a hot spot in global environment change. This study will allow predicting areas, which are prone to the rapid environmental change. Eight classes were classified and compare with MODerate resolution Imaging Spectrometer (MODIS) global land cover. The time-series analysis was carried out for these 8 classes. Class-1 and -2 have least amplitude variation with low NDVI as barren areas, while other vegetated classes increase in May and decrease in October (maximum value occurs in July and August). Although the several classes have the similar features of NDVI time-series, we detected a slight difference of inter-annual variation among these classes.

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A study on possibility of land vegetation observation with Mid-resolution sensor

  • Honda, Y.;Moriyama, M.;Ono, A.;Kajiwara, K.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.349-352
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    • 2007
  • The Fourth Assessment Report of IPCC predicted that global warming is already happening and it should be caused from the increase of greenhouse gases by the extension of human activities. These global changes will give a serious influence for human society. Global environment can be monitored by the earth observation using satellite. For the observation of global climate change and resolving the global warming process, satellite should be useful equipment and its detecting data contribute to social benefits effectively. JAXA (former NASDA) has made a new plan of the Global Change Observation Mission (GCOM) for monitoring of global environmental change. SGLI (Second Generation GLI) onboard GCOM-C (Climate) satellite, which is one of this mission, provides an optical sensor from Near-DV to TIR. Characteristic specifications of SGLI are as follows; 1) 250 m resolutions over land and area along the shore, 2) Three directional polarization observation (red and NIR), and 3) 500 m resolutions temperature over land and area along shore. These characteristics are useful in many fields of social benefits. For example, multi-angular observation and 250 m high frequency observation give new knowledge in monitoring of land vegetation. It is expected that land products with land aerosol information by polarization observation are improved remarkably. We are studying these possibilities by ground data and satellite data.

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휴대용 근적외선 카메라를 이용한 소나무 재선충 피해목의 식생지수 변화분석 (Analyzing Vegetation Index Change of Damaged Trees by Pine Wilt Disease Using Portable Near Infrared Camera)

  • 김유승;정성은;이우균;김준범;권태형
    • 한국산림과학회지
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    • 제97권6호
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    • pp.561-564
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    • 2008
  • 소나무 재선충병은 우리나라 소나무림에 심각한 위협이 되고 있다. 소나무 재선충병은 보통 5~6월에 감염되지만 10~11월에 비로소 피해목을 육안으로 확인할 수 있어, 피해예방에 큰 어려움을 겪고 있다. 재선충에 의해 소나무가 고사되는 과정중에는 식생활력도가 크게 감소하게 되는데, 이러한 현상은 분광스펙트럼상의 근적외선 영역에서 분광반사의 감소를 수반한다. 본 연구에서는 이러한 현상을 토대로 재선충 피해목의 식생활력도 변화를 식생지수 모니터링을 통하여 분석하였다. 휴대가 간편한 근적외선 카메라를 이용하여 재선충 피해지역의 소나무림을 5월부터 11월까지 매월 촬영함으로써 녹색, 적색 및 근적외선 영역대의 분광반사값을 취득하였다. 이렇게 수집된 분광반사값으로부터 피해목의 식생지수(Vegetation Index: VI)의 변화를 분석하였고, 피해목의 식생지수는 감염초기인 6월부터 감소하기 시작한다는 것을 밝힐 수 있었다.