• Title/Summary/Keyword: forest cover

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An Analysis on Spatio-Temporal Changes of Land Cover focusing on NDVI Using GIS and RS in Pyeongbuk Province, Northwest Korea (GIS와 RS를 이용한 토지피복 및 식생 분포의 시ㆍ공간적 변화 - 평안북도 서부 지역을 중심으로 -)

  • 이민부;김남신;최한성;신근하
    • Journal of the Korean Geographical Society
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    • v.38 no.5
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    • pp.835-848
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    • 2003
  • This study deals with the spatio-temporal change of land cover and vegetation distribution between 1988 and 2001 using remote sensing images and CIS techniques in west area of Pyeongbuk Province, northwest Korea. Landsat TM and ETM images are geometrically and radiometrically corrected for the analysis of land cover and NDVI. Forested areas are decreased during 13 year from 1988 to 2001 in study area including Sakju, Daegwan, Guseong and Euiju of Pyeongbuk Province, because wasteland are increased by human impact and denuded land by landslide and flooding. DEM analysis presents that settlement and cropland are developed toward higher and steeper mountain slope, together with decrease NDIV values. these changes have resulted from unplanned increase of cropland without consideration of geomorphic condition. Therefore, more researches and reasonable policies are required to protect forest and cropland and stable food supply against natural hazard like landslide.

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.

An Example of Changed Design through the Face Mapping and Slope Analysis (절토사면 현황도 작성 및 분석에 따른 설계변경 사례연구)

  • Lee, Byung-Joo;Chae, Byung-Gon;Lee, Kyoung-Mi
    • The Journal of Engineering Geology
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    • v.24 no.1
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    • pp.137-146
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    • 2014
  • The geology of the study area which is located in Samkoe-dong, Dong-gu, Daejeon city comprises black slate, limestone, and pebble-bearing phyllitic rock as meta-sedimentary rocks; and biotite granite and quartz porphyry intrusions. Face mapping revealed sliding in three or four sites of contained coaly slate, where the dip of the foliation and other discontinuities is parallel to the surface slope. The cause of the slope sliding is this parallelism as well as the swelling of the coaly slate when wet. In contrast, the slop on the opposite side of the road is relatively stable because the dip of the foliation and other discontinuities are oblique or normal to the surface slope. To ensure slope stability, a cut-and-cover tunnel was designed and constructed for the new road.

Analysis on the Quarry Restoration Methods in Hong Kong (홍콩의 채석장 식생복원공법에 관한 분석)

  • Park, Chong-Min;Lee, Joon-Woo;Youn, Ho-Joong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.5
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    • pp.121-132
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    • 2009
  • The agency which is responsible for work related to the restoration of vegetation on the quarry in Hong Kong is the Geotechnical Engineering Office of Civil Engineering and Development Department (CEDD). CEDD's environmental management system was certified as ISO 14001 : 2004 in 2006 and diverse instructions and technical documents about the restoration of the quarry were published and used for the performance of work and the implementation of the project. The restoration of the quarry is being carried out to respond to short-term and long-term goals. The general instructions for the restoration of vegetation says that a plant, when selected, should be self-sustainable with minimum maintenance required, have a high growth and survival rate, be tall enough to cover the rock slope faces, and preferably produce colourful flowers. These instructions prescribe the vegetation introduction technology, planting seasons, structural material of the vegetation works, maintenance and management, tree nursery operation, means of water supply, etc. This report introduced the outline of work on restoring vegetation carried out at Anderson Road, Shek O, Lam Tei, Turret Hill, Lamma, all large-sized quarries. In addition, it additzed Anderson Road's master plan. It is hoped that the Hong Kong examples so introduced are referred to in terms of institutional and technical considerations related to the nation's project for restoring quarries.

Population Dynamics of Pinus densiflora for. erecta at Sokwang-Ri, Uljin-Gun in Southeastern Korea

  • Yun, Chung-Weon;Bae, Kwan-Ho;Hong, Sung-Cheon
    • The Korean Journal of Ecology
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    • v.24 no.6
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    • pp.341-348
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    • 2001
  • Population dynamics of the oldest relic stand of Pinus densiflora for. erecta which remains as a status of patch in Sokwang-Ri area, Uljin-Gun, was studied to provide the basic data for conservation of the oldest pine stand in Korea. The upper slope site and ridge site including total 12 plots mainly represented Pinus densiflora for. erecta and Quercus mongolica. These two tree species showed reverse J-shaped distribution. From this information, it was concluded that intensive interspecific competition between two species could be occurring. Age distribution of P. densiflora for. erecta on the sites above middle slope area was indicated bi-modal type or tri-modal type which was known as an age structure of climax forest. Therefore, it was estimated that Pinus densiflora for. erecta population could be continuously maintained in the each patch above middle slope area. In the valley sites, hardwood species such as Q. mongolica, Q. variabilis, Styrax obassia and Acer pseudosieboldianum occupied most part of the under crown-cover area and their seedlings and saplings were developing into the closed upper layer crown because the height of upper layer crown reached about 35 meters and such a high crown height was more suitable for light utilization by plants of under layer. The growth patterns were mainly fluctuated for the entire life time of the oldest tree caused by frequent disturbance. And the initial growth curves of the mature trees and suppressed juvenile trees showed different tendencies along the sites.

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APPLICATION AND CROSS-VALIDATION OF SPATIAL LOGISTIC MULTIPLE REGRESSION FOR LANDSLIDE SUSCEPTIBILITY ANALYSIS

  • LEE SARO
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.302-305
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    • 2004
  • The aim of this study is to apply and crossvalidate a spatial logistic multiple-regression model at Boun, Korea, using a Geographic Information System (GIS). Landslide locations in the Boun area were identified by interpretation of aerial photographs and field surveys. Maps of the topography, soil type, forest cover, geology, and land-use were constructed from a spatial database. The factors that influence landslide occurrence, such as slope, aspect, and curvature of topography, were calculated from the topographic database. Texture, material, drainage, and effective soil thickness were extracted from the soil database, and type, diameter, and density of forest were extracted from the forest database. Lithology was extracted from the geological database and land-use was classified from the Landsat TM image satellite image. Landslide susceptibility was analyzed using landslide-occurrence factors by logistic multiple-regression methods. For validation and cross-validation, the result of the analysis was applied both to the study area, Boun, and another area, Youngin, Korea. The validation and cross-validation results showed satisfactory agreement between the susceptibility map and the existing data with respect to landslide locations. The GIS was used to analyze the vast amount of data efficiently, and statistical programs were used to maintain specificity and accuracy.

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CROSS-VALIDATION OF ARTIFICIAL NEURAL NETWORK FOR LANDSLIDE SUSCEPTIBILITY ANALYSIS: A CASE STUDY OF KOREA

  • LEE SARO;LEE MOUNG-JIN;WON JOONG-SUN
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.298-301
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    • 2004
  • The aim of this study is to cross-validate of spatial probability model, artificial neural network at Boun, Korea, using a Geographic Information System (GIS). Landslide locations were identified in the Boun, Janghung and Youngin areas from interpretation of aerial photographs, field surveys, and maps of the topography, soil type, forest cover and land use were constructed to spatial data-sets. The factors that influence landslide occurrence, such as slope, aspect and curvature of topography, were calculated from the topographic database. Topographic type, texture, material, drainage and effective soil thickness were extracted from the soil database, and type, diameter, age and density of forest were extracted from the forest database. Lithology was extracted from the geological database, and land use was classified from the Landsat TM image satellite image. Landslide susceptibility was analyzed using the landslide­occurrence factors by artificial neural network model. For the validation and cross-validation, the result of the analysis was applied to each study areas. The validation and cross-validate results showed satisfactory agreement between the susceptibility map and the existing data on landslide locations.

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A New Forest Fire Detection Algorithm using Outlier Detection Method on Regression Analysis between Surface temperature and NDVI

  • Huh, Yong;Byun, Young-Gi;Son, Jeong-Hoon;Yu, Ki-Yun;Kim, Yong-Il
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.574-577
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    • 2006
  • In this paper, we developed a forest fire detection algorithm which uses a regression function between NDVI and land surface temperature. Previous detection algorithms use the land surface temperature as a main factor to discriminate fire pixels from non-fire pixels. These algorithms assume that the surface temperatures of non-fire pixels are intrinsically analogous and obey Gaussian normal distribution, regardless of land surface types and conditions. And the temperature thresholds for detecting fire pixels are derived from the statistical distribution of non-fire pixels’ temperature using heuristic methods. This assumption makes the temperature distribution of non-fire pixels very diverse and sometimes slightly overlapped with that of fire pixel. So, sometimes there occur omission errors in the cases of small fires. To ease such problem somewhat, we separated non-fire pixels into each land cover type by clustering algorithm and calculated the residuals between the temperature of a pixel under examination whether fire pixel or not and estimated temperature of the pixel using the linear regression between surface temperature and NDVI. As a result, this algorithm could modify the temperature threshold considering land types and conditions and showed improved detection accuracy.

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Palynological Study of Akindonuma Moor in the Central Oh-u Backbone Range, Northeasternl Japan

  • Park, Ji-Hoon
    • The Korean Journal of Ecology
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    • v.25 no.1
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    • pp.45-49
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    • 2002
  • Pollen analyses and $^{14}$ C dating of the sediments of the Akindonuma moor, which is situated in a closed depression of an old landslide, were peformed in order to study the vegetation history of the montane zone of the Miyagi Prefecture, Northeast Japan. The main results are as follows: Two forest zones have been distinguished: 1) the A-I zone, or the Fagus-Quercus-Betula forest (R I stage, before about 11,700 yrs B.P.), and 2) the A-II zone, or the Fagus-Quercus forest (R II stage, after about 11,700 yrs B.P.). By comparing the geological section with the pollen diagram of the moor, it is assumed that the deposit environment of the Middle Part, which mostly consists of peat layers, is very stable. During the period, the Ulmus/Zelfkova pollen ratio was very low and small peak was not recognized. According to the preceding research, theme is a close relationship between the fluctuation of the Ulmus/Zelkova pollen ratio and the general trend of hillslope instability in the changing balance of temporature and precipitation Actually, Zelkova serrata tends to cover the footslope and the lower sideslope. Ulmus davidiana covers the footslope and the alluvial cone. Therefore, the fact that the Ulmus/Zeikova pollen ratio was very low and small peak was not recognized, is believed to reflect the stability of the earth's surface environment, which was estimated from the geological section.

Influence of Landuse Pattern and Seasonal Precipitation on the Long-term Physico-chemical Water Quality in Namhan River Watershed (남한강 수계에서 장기 이화학적 수질특성에 대한 토지이용도 및 계절성 강우의 영향)

  • Lee, Ji-Eun;Choi, Ji-Woong;An, Kwang-Guk
    • Journal of Environmental Science International
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    • v.21 no.9
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    • pp.1115-1129
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    • 2012
  • The objective of this study was to analyze long-term annual and seasonal trends of water chemistry on landuse patterns and seasonal precipitation using 72 sampling sites within Namhan River watershed during 2001-2010. Water quality, based on multi-parameters of water temperature(WT), dissolved oxygen(DO), biochemical oxygen demand(BOD), chemical oxygen demand(COD), suspended solids(SS), total nitrogen(TN), total phosphorus(TP), and electric conductivity(EC) varied largely depending on monsoon rain and landuse patterns such as forest, cropland, and residence. Concentrations of BOD and COD as an indicator for organic matter pollution, increased during summer monsoon season at the cropland and residential streams. Values of TN and TP were higher in residential streams than in the forest and cropland streams. In the meantime, DO values had weak relations to the landuse patterns of forest and cropland cover. Water quality was worst in cropland and residential streams, and also most degradated in 4th order streams. Overall, our results suggest that efficient water quality management is required in the cropland and residential landuse streams.