• Title/Summary/Keyword: 사막화

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A study for Desertification Monitoring and Assessment based on satellite imagery in Tunisia (위성영상기반 튀니지 사막화 모니터링 및 평가에 관한 연구)

  • KIM, Ji-Won;SONG, Chol-Ho;PARK, Eun-Been;LEE, Jong-Yeol;CHOI, Sol-E;LEE, Eun-Jung;LEE, Woo-Kyun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.4
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    • pp.91-107
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    • 2018
  • It is required to monitor and assess the desertification in Tunisia, where the Sahara Desert, which is located in the southern part of Tunisia, is recently expanding northward. In this study, by using remote sensed data, land cover changes were examined, and the Normalized Difference Vegetation Index (NDVI), Topsoil Grain Size Index (TGSI) and Albedo are used to monitor and assess desertification in Tunisia. Decision Tree was constructed, and the frequencies and trends of each assessment indicator, desertification degree and land cover were identified. In addition, we analyzed the correlation between assessment indicators and precipitation. As a result, desertification is generally intensifying northward, especially in areas with high levels of desertification. Also, bivariate correlation analysis showed that Albedo, NDVI and TGSI were all highly correlated with precipitation. It indicates that changes in precipitation have also been shown to affect Tunisian desertification. In conclusion, this study has improved the usability of various methodologies considering the assessment indicators based on satellite imagery, Decision Tree, which is a method of evaluating them complexly, and trends of land cover change.

Crisis Construction in the Inner Mongolia Grassland and the Controversy of Desertification: The Emergence of Grassland Chicken Farming (중국 내몽고 초원의 위기와 사막화 논쟁 -초원목계(草原牧鷄)가 등장하기까지-)

  • Lee, Seonhwa
    • Journal of the Korean Geographical Society
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    • v.47 no.6
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    • pp.836-852
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    • 2012
  • Based on a long-term ethnographic study, this paper examines how the propositions and practices for desertification management in Inner Mongolia, China have changed over time. Desertification as an ecological issue cannot simply be treated as a something "natural" or "social," while it is an outcome of the construction made by both human and non-human agents. My research has found that the propositions for desertification management have been involved in the process of defining desertification, particularly by selecting different actors related to the ecological process in this region. Ultimately, the crisis in the inner Mongolia has always been constructed by the ways in which the selected actors and their relationships are differently defined. My study also reveals that although the proposed preventive measures, including afforestation, area protection, and pasturing prohibition, have tried to reconcile the conflicts of interest among the different actors, they have always been faced with certain limitations and failed in dryland management. In this historical context of crisis construction, by introducing a new non-human agent, "the chicken," the project of grassland chicken farming has eventually appeared to be an innovative strategy that can overcome the earlier limitations and coordinate the interests of Mongolian pastoralists who have suffered from economic difficulty.

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Vegetation Water Status Monitoring around China and Mongolia Desert: SPOT VEGETATION Data use (중국과 몽골 사막주변의 식생수분상태 탐지 : SPOT VEGETATION 자료 이용)

  • Lee, Ga-Lam;Yeom, Jong-Min;Lee, Chang-Suk;Pi, Kyoung-Jin;Park, Soo-Jae;Han, Kyung-Soo;Kim, Young-Seup
    • Proceedings of the KSRS Conference
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    • 2009.03a
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    • pp.101-104
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    • 2009
  • 기후 시스템에서 지구온난화는 세계적으로 매우 중요한 문제이고 이는 기후변화, 이상기온, 폭우, 가뭄 등의 문제를 초래한다. 특히 사막화는 전 세계적으로 10억 명 이상의 사람들에게 영향을 미치고 있다. 건조한 상태의 식생은 사막화되기 쉽기 때문에 식생의 수분상태는 사막화의 중요한 지표이다. 본 논문에서는 중국과 몽골 사막 주변영역에 대해 식생의 수분상태를 탐지하였다. 식생의 수분상태를 탐지하기 위해 1999년부터 2006년까지의 SPOT/VEGETATION 위성 이미지를 이용하여 정규화 수분지수(NDWI: Normalized Difference Water Index)를 산출하였다. 그 결과 1999년부터 2006년까지의 NDWI는 사막주변영역에서 감소하는 경향을 보였고, 그 영역은 몽골 고비사막 북동지역과 중국 타클라마칸 사막의 남동지역에 위치해 있었다.

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Effects on dust concentrations and Ca/AI ratio during sandstorm in Seoul (황사발생이 먼지농도와 Ca/Al농도비에 미치는 영향)

  • 김민영;이민환;여인학;조석주;윤중섭;김광래
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.05b
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    • pp.184-186
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    • 2003
  • 황사현상은 세계적 규모의 사막화진행과 무관치 않는 지구환경의 중요한 한 부분이다. UNEP의 현황조사에 의하면 세계의 육지면적의 약1/4, 즉 건조지대의 약 70%에 해당하는 약36억ha가 사막화하여 세계인구의 약1/6이 직접 영향을 받는 것으로 추정하고 있다. 사막화의 피해가 세계의 각대륙에서 나타나고 있지만 특히 아프리카대륙, 다음이 아시아의 황폐화가 현저하다. (중략)

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The Land Use Change and the Desertification in the East Inner Mongolia, China - A Case Study on Horqin Desert - (중국 내몽고 동부지역의 토지이용 변화와 사막화 -커얼친 사지의 사례 -)

  • Lee Kang-Won
    • Journal of the Korean Geographical Society
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    • v.40 no.6 s.111
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    • pp.694-715
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    • 2005
  • I examine in this paper the change of land use and the development of desertification in Horqin desert, east Inner Mongolia, China. The change of land use in this area can be summarized as the increase of agricultural field and intensive livestock farming. The agriculture and livestock farming in semi-arid area such as Horqin desert raised the problem in the management and use of water and vegetation. This problem led to desertification. The types of development of desertification in this area could be classified as follows: the mobile sand dune extension, the riverside shifting sand flat extension, the shifting sand speck extension around settlements, and the shifting sand speck extension in agricultural Held and grassland. There have been political or social movements such as the Great Leap Forward, the Cultural Revolution and the Reform and Open Policy in the background of land use change and desertification. Specially, the Great Leap Forward and the Cultural Revolution played an important role in the land use change and desertification in this area. Since 1990s, there has been some kind of policy in the control of desertification. However, it is necessary for the controling desertification of this area to consider the globalization and marketization, the survival and profit of peasants and livestock farmers, and the disturbrd and fixed population and land use structure in this area since 1949.

Analysis of Land Cover Change Around Desert Areas of East Asia (식생 자료를 이용한 동아시아 사막 주변의 토지피복 변화 분석)

  • Ryu, Jae-Hyun;Han, Kyung-Soo;Pi, Kyoung-Jin;Lee, Min-Ji
    • Korean Journal of Remote Sensing
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    • v.29 no.1
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    • pp.105-114
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    • 2013
  • Desertification of the East Asia area induced by human's indiscriminate activities and natural causes has gradually expanded and demanded scientific research for monitoring and predicting land cover condition. Therefore, this research classified land types which were compared to MODIS land cover and analyzed the extent of barren zone effecting Korea through yellow dust using S10-DAY MVC NDVI from SPOT between 1999 and 2011. This study used unsupervised classification after processing NDVI Correction and Water Mask for eliminating noise values included in the data for enhancement of classification accuracy. The results of analysis are that there are active variations near the borders of desert, especially the Mongolian steppe and the Gobi Desert in central Asia. In addition, the extent of entire desert has been decreased in the middle of the last decade, although desertification is in going on in East Asia.

Detection of Land Cover Change Using Landsat Image Data in Desert Area (Landsat 영상자료를 이용한 사막지역의 토지피복 변화 분석)

  • M, Erdenechimeg;Choi, Byoung-Gil;Na, Young-Woo;Kim, Tae-Hoon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.4
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    • pp.471-476
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    • 2010
  • This study aimed at monitoring, mapping, and assessing the land degradation in the desert area. In this research, the Landsat TM and ETM+ imageries to assess the extent of land degradation for study area during the period from 1991 to 2007. Were used to study supervized, unsupervized classfication and NDVI land cover changes in the desert area in Mongolia. The classified map consists of five classes of water, vegetation, slight desertification, middle desertification and sever desertification. It shows that for determination classfication methods and NDVI, desertification map of the study area are prepared. The result showed accounting for a clear deterioration in vegetative cover, an increase of sever desertification and a decrease in middle desertification and slight desertification respectively of the total study area.

Vegetation Water Status Monitoring around China and Mongolia Desert using Satellite Data (위성자료를 이용한 중국과 몽골 사막주변의 식생수분상태 모니터링)

  • Lee, Ga-Lam;Kim, Young-Seup;Han, Kyoung-Soo;Lee, Chang-Suk;Yeom, Jong-Min
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.4
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    • pp.94-100
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    • 2008
  • Recently, global warming for climate system is a crucial issue over the world and it brings about severe climate change, abnormal temperature, a downpour, a drought, and so on. Especially, a drought over the earth surface accelerates desertification which has been advanced over the several years mainly originated from a climatic change. The objective of this study is to detect variation of vegetation water condition around China and Mongolia desert by using satellite data having advantage in observing surface biological system. In this study, we use SPOT/VEGETATION satellite image to calculate NDWI (Normalized Difference Water Index) around study area desert for monitoring of status of vegetation characteristics. The vegetation water status index from remotely sensing data is related to desertification since dry vegetation is apt to desertify. We can infer vegetation water status using NDWI acquired by NIR (Near infrared) and SWIR (Short wave infrared) bands from SPOT/VGT. The consequence is that NDWI decreased around desert from 1999 to 2006. The areas that NDWI was decreased are located in the northeast of Mongolian Gobi desert and the southeast of China Taklamakan desert.

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