• 제목/요약/키워드: China desert

검색결과 51건 처리시간 0.027초

사막화방지(沙漠化防止) 및 방사기술개발(防沙技術開發)에 관한 연구(硏究)(I) - 중국(中國)의 사막화현황(沙漠化現況) 및 방지대책(防止對策) - (Studies on the Desertification Combating and Sand Industry Development(I) - Present Status and Countermeasures for the Combating Desertification in China -)

  • 우보명;이경준;전기성;김경훈;최형태;이승현;이병권;김소연;이상호;전정일
    • 한국환경복원기술학회지
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    • 제3권3호
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    • pp.45-76
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    • 2000
  • The purposes of this study were to investigate and understand the present status of various types of "deserts", such as sand desert, gravel desert, rock desert, earth desert, salt desert, desert, rocky desert, gobi desert, sandy desert, clay desert, etc., and the general countermeasures for the combating "desertification" "desertization", and to develop the technologies on the revegetation and restoration for the combating desertification in China. The methods of this study were mainly composed of field surveys on the several experimental sites and research institutes related to combating desertification in China, and examinations on the various technologies for the combating desertification at the Daxing Experimental Station of Beijing Forestry University. The conclusion from this study may be summarized as follows; 1. Status and tendency of desertification in China : China is one of the countries seriously threatened by desertification. Desertification affected areas in China are mainly distributed in arid, semi-arid and dry sub-humid areas in China, covering the most regions of the Northeast China (eastern region of Inner-Mongolia), the northern part of the North China (middle and western region of Inner-Mongolia, Shaanxi, Ningsha, Gansu) and the western part of the Northwest China (Xinzang, Qinghai, Xizang). The total area affected by desertification in China is approximately 2.622 million $km^2$. It covers 27.3% of the total territory of China. Until recently, it is estimated that the annual spreading ratio of desertification in China is 2,460 $km^2$. Therefore, desertification is mostly serious problems facing to the Chinese people. 2. The causes and environmental effect of desertification : The desertification in China is mainly caused by compound factors, including natural condition and human activities. In China, the desertification is started by the decrease of precipitation, continuous dry and drought, strong wind, wind and water erosion, land degradation and loss of natural vegetation caused by climate variation, and accelerated by the human activities, such as over-cultivating, over-grazing, over-cutting of woods, irrational use of water resources. Because desertification has affected the geographical features, soil nutrients contents, salinity, vegetation coverage and the functions of ecosystem, the environmental deteriorations in the desertification affected areas are very seriously. 3. The fundamental strategies of combating desertification in China are the increase of education and awareness of people through various mass media, the revision of laws to guarantee operation of Desertification Combating Law and to improve many relating laws and regulations, the application of advanced technologies and training of experts, the establishment of discriminative policies, and increasing arrangement of budget-investment, and so on. China, as a signed country in UNCCD, has made efforts for the combating desertification. Korea is also signed country in UNCCD, so we should play an important role in the desertification combating projects of China for the northest asia and global environmental conservation as well as environmental conservation of Korea.

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Identification of Source Locations for Atmospheric Dry Deposition of Heavy Metals during Yellow-Sand Events in Seoul, Korea in 1998 Using Hybrid Receptor Models

  • Han, Young-Ji;Holsen, Thomas M.;Hopke, Philip K.;Cheong, Jang-Pyo;Kim, Ho;Yi, Seung-Muk
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2004년도 International Conference Global Environmental Problems and their Health Consequences
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    • pp.92-106
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    • 2004
  • Elemental dry deposition fluxes were measured using dry deposition plates from March to June 1998 in Seoul, Korea. During this spring sampling period several yellow sand events characterized by long-range transport from China and Mongolia impacted the area. Understanding the impact of yellow-sand events on atmospheric dry deposition is critical to managing the heavy metal levels in the environment in Korea. In this study, the measured flux of a primarily crustal metal, Al and an anthropogenic metal, Pb was used with two hybrid receptor models, potential source contribution function (PSCF) and residence time weighted concentration (RTWC) for locating sources of heavy metals associated with atmospheric dry deposition fluxes during the yellow-sand events in Seoul, Korea. The PSCF using a criterion value of the 75th percentile of the measured dry deposition fluxes and RTWC results using the measured elemental dry deposition fluxes agreed well and consistently showed that there were large potential source areas in the Gobi Desert in China and Mongolia and industrial areas near Tianjin, Tangshan, and Shenyang in China. Major industrial areas of Shenyang, Fushun, and Anshan, the Central China loess plateau, the Gobi Desert, and the Alaskan semi-desert in China were identified to be major source areas for the measured Pb flux in Seoul, Korea. For Al, the main industrial areas of Tangshan, Tianjin and Beijing, the Gobi Desert, the Alashan semi-desert, and the Central China loess plateau were found to be the major source areas. These results indicate that both anthropogenic sources such as industrial areas and natural sources such as deserts contribute to the high dry deposition fluxes of both Pb and Al in Seoul, Korea during yellow-sand events. RTWC resolved several high potential source areas. Modeling results indicated that the long-range transport of Al and Pb from China during yellow-sand events as well as non yellow-sand spring daytimes increased atmospheric dry deposition of heavy metals in Korea.

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Effect of Restricted Grazing Time on the Foraging Behavior and Movement of Tan Sheep Grazed on Desert Steppe

  • Chen, Yong;Luo, Hailing;Liu, Xueliang;Wang, Zhenzhen;Zhang, Yuwei;Liu, Kun;Jiao, Lijuan;Chang, Yanfei;Zuo, Zhaoyun
    • Asian-Australasian Journal of Animal Sciences
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    • 제26권5호
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    • pp.711-715
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    • 2013
  • To investigate the effect of restricted grazing time on behavior of Tan sheep on desert steppe, forty 4-months old male Tan sheep with an original body weight (BW) of $15.62{\pm}0.33$ kg were randomly allocated to 4 grazing groups which corresponded to 4 different restricted grazing time treatments of 2 h/d (G2), 4 h/d (G4), 8 h/d (G8) and 12 h/d (G12) access to pasture. The restricted grazing times had a significant impact on intake time, resting time, ruminating time, bite rate and movement. As the grazing time decreased, the proportion of time spent on intake, bite rate and grazing velocity significantly (p<0.05) increased, but resting and ruminating time clearly (p<0.05) decreased. The grazing months mainly depicted effect on intake time and grazing velocity. In conclusion, by varying their foraging behavior, Tan sheep could improve grazing efficiency to adapt well to the time-limited grazing circumstance.

Physicochemical Properties of Asian Dust Sources

  • Ma, Chang-Jin;Kasahara, Mikio;Tohno, Susumu;Kim, Ki-Hyun
    • Asian Journal of Atmospheric Environment
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    • 제2권1호
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    • pp.26-33
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    • 2008
  • In order to fully understand the chemical properties of Asian dust particles, especially their transformation and aging processes, it is desirable to investigate the nature of original sands collected at local source areas in China. This study presents the detailed properties of sands collected at four different desert regions (Yinchuan, Wuwei, Dulan, and Yanchi) in China. Most of sands have irregular shape with yellowish coloration, whereas some of them show peculiar colors. The relative size distribution of sands collected at Yinchuan, Wuwei, and Dulan deserts exhibits monomodal with the maximum level between 200 and $300{\mu}$, whereas that of Yanchi desert is formed between 100 and $200{\mu}$. The mass concentration ratio of each element to that of Si (Z/Si) determined by PIXE analysis has a tendency towards higher Z/Si ratios for soil derived elements. It was possible to visually reconstruct the elemental maps on the surface of individual sands by XRF microprobe technique. In addition, the multielemental mass concentration could be quantitatively calculated for numerous spots of desert sands.

Grain-Size Distribution of Source Areas of Asian Dust (Yellow Sand) in China

  • Yi, Hi-Il;Shin, Im-Chul
    • 한국제4기학회지
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    • 제21권2호
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    • pp.77-79
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    • 2007
  • The source regions of Asian Dusts (Yellow Sands) in the western part of China are investigated, and the soil samples are collected samples for approximately 15 days during the spring of 2005. Particle sizes of sediments are analyzed and compared with each other. These grain-size analyses from the source areas can be compared Particle sizes between loess deposits and desert sands in western part of China and desert areas show distinctive differences. Loess deposits are predominantly composed of fine sands and silts. The distinction between the final characteristics of Asian Dust particles arrived in Korea and characteristics during transportation can be recognized comparison with the Asian Dust particles collected where the dust particles settled down. The characteristics of Asian Dust particle sizes can provide the basic information regarding the transportation history from the source region.

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The Natural Environment during the Last Glacial Maximum Age around Korea and Adjacent Area

  • Yoon, Soon-Ock;Hwang, Sang-Ill
    • 한국제4기학회지
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    • 제17권2호
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    • pp.33-38
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    • 2003
  • This study is conducted to examine the data of climate or environmental change in the northeastern Asia during the last glacial maximum. A remarkable feature of the 18,000 BP biome reconstructions for China is the mid-latitude extention of steppe and desert biomes to the modem eastern coast. Terrestrial deposits of glacial maximum age from the northern part of Yellow Sea suggest that this region of the continental shelf was occupied by desert and steppe vegetation. And the shift from temperate forest to steppe and desert implies conditions very much drier than present in eastern Asia. Dry conditions might be explained by a strong winter monsoon and/or a weak summer monsoon. A very strong depression of winter temperatures at LGM. has in the center of continent has influenced in northeast Asia similarly. The vegetation of Hokkaido at LGM was subarctic thin forest distributed on the northern area of middle Honshu and cool and temperate mixed forest at southern area of middle Honshu in Japan. The vegetation landscape of mountain- and East coast region of Korea was composed of herbaceous plants with sparse arctic or subarctic trees. The climate of yellow sea surface and west region of Korea was much drier and temperate steppe landscape was extended broadly. It is supposed that a temperate desert appeared on the west coast area of Pyeongan-Do and Cheolla-Do of Korea. The reconstruction of year-round conditions much colder than today right across China, Korea and Japan is consistent with biome reconstruction at the LGM.

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

  • 이가람;김영섭;한경수;이창석;염종민
    • 한국지리정보학회지
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    • 제11권4호
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    • pp.94-100
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    • 2008
  • 기후 시스템에서 지구온난화는 세계적으로 매우 중요한 문제이고 이는 기후변화, 이상기온, 폭우, 가뭄 등의 문제를 초래한다. 특히 가뭄은 기후변화에 의해 여러 해 동안 진행되어온 사막화를 가속화시킨다. 본 연구의 목적은 중국과 몽골 사막주변의 식생수분상태를 탐지하는 것이다. 본 연구에서는 중국과 몽골 사막 주변의 식생수분지수를 산출하기 위해 1999년부터 2006년까지의 SPOT/VEGETATION 위성 이미지를 이용하여 정규수분지수(NDWI: Normalized Difference Water Index)를 산출하였다. 건조한 상태의 식생은 사막화되기 쉽기 때문에 식생 수분은 사막화의 중요한 지표이다. SPOT/VEGETATION 위성영상의 근적외밴드(NIR)와 단파적외밴드(SWIR)의 밴드간 연산을 통하여 NDWI를 구하여 식생의 수분입자를 측정하였다. 그 결과 1999년부터 2006년까지의 NDWI는 사막주변영역에서 감소하는 경향을 보였고, 그 영역은 몽골 고비사막 북동지역과 중국 타클라마칸 사막의 남동지역에 위치해 있었다.

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

  • 이강원
    • 대한지리학회지
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    • 제40권6호
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    • pp.694-715
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    • 2005
  • 이 논문은 중국의 반건조지대에 위치하는 네이멍구 동부의 커얼친 사지를 사례로 토지이용의 변화와 사막화의 전개에 대하여 검토하고 있다. 이 지역의 토지이용의 변화는 경지와 목축두수의 증가로 요약되며, 그에 따른 물과 식생의 이용 및 관리에 있어서의 문제점들이 사막화를 촉진시킨 것으로 나타났다. 사막화의 전개 유형은 이동사구 확대 유형, 하안 유사 확대 유형, 촌락 주변 반점상 유사 확대 유형, 초지와 경지 중의 반점상 유사 확대 유형으로 구분할 수 있었다. 토지이용 변화의 배경에는 1949년이래 사회주의 건설과 개혁개방으로 요약되는 사회적 변화가 자리 잡고 있다. 특히 대약진운동과 문화대혁명이라는 두 가지 정치적 운동과 개혁개방으로 인한 농민과 목축민들의 수익추구가 이 지역의 토지이용에 미친 영향이 컸다. 1990년대를 전후하여 사막화에 대한 각성과 더불어 여러 가지 사막화 예방 및 퇴치 정책들이 실시되고 있다. 그러나 이러한 정책들은 개방화 및 시장화라는 추세, 이 지역 농민들과 목축민들의 생존권과 수익, 그리고 무엇보다도 1949년 이후 이 지역에 고착된 교란된 인구구조와 그에 따른 토지이용체계에 의해 제약받고 있다.

Contribution of Urine and Dung Patches from Grazing Sheep to Methane and Carbon Dioxide Fluxes in an Inner Mongolian Desert Grassland

  • Jiang, Yuanyuan;Tang, Shiming;Wang, Chengjie;Zhou, Pei;Tenuta, Mario;Han, Guodong;Huang, Ding
    • Asian-Australasian Journal of Animal Sciences
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    • 제25권2호
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    • pp.207-212
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    • 2012
  • The effects of sheep urine and dung patches on methane ($CH_4$) and carbon dioxide ($CO_2$) fluxes were investigated during the summer-autumn in 2010, to evaluate their contribution to climate change in a desert grassland in Inner Mongolia, China. Results indicate that the cumulative $CH_4$ emissions for dung patches, urine patches and control plots were -0.076, -0.084, and -0.114 g/$m^2$ and these were net $CH_4$ sinks during the measured period. The level of $CH_4$ intake from urine and dung plots decreased 25.7%, and 33.3%, respectively, compared with a control plot. $CO_2$ fluxes differed (p<0.01) in urine plots, with an average of 569.20 mg/$m^2$/h compared with control plots (357.62 mg/$m^2$/h) across all sampling days. Dung patches have cumulative $CO_2$ emissions that were 15.9% higher compared with the control during the 55-d period. Overall, sheep excrement weakened $CH_4$ intake and increased $CO_2$ emissions.