• Title/Summary/Keyword: forest cover

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Evaluation of Land Cover Classification of Pyeong-Taeg Area by Landsat Thematic Mapper Data (Landsat TM 영상자료를 이용한 평택지역의 토지피복 현황 및 분류정확도 평가)

  • 윤성탁;김선오;임상규
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.3 no.3
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    • pp.163-170
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    • 2001
  • The objective of this study was to evaluate land cover classification of PyeongTaeg area by Landsat Thematic Mapper Data June, 1997. This study was also to make more correct reference data using DGPS, aerophoto, and topographical chart etc.. The result of the area of paddy and upland were estimated 4,949 $\textrm{km}^2$ and 16,157 $\textrm{km}^2$, respectively. Correctness of estimation by using DGPS, aerophoto, topographical chart were shown over 90% correct in case of rice paddy field, water, and sea, while upland, vinyl house, forest, grassland, village were shown low correctness. Total average accuracy was shown to be 85.8%. Correctness of paddy field showed high value of 92%, showing that use of remote sensing data was proved to be effective methods to estimate spatial distribution and cultivation status of paddy field. Classification result of sea, water area, downtown had higher correctness, while upland, vinyl-house, grassland were proved to be relatively low correctness because of it's small area and mixed distribution.

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Comparison of postharvest quality of Aralia elata shoot according to packaging methods

  • Yonghyun Kim;Narae Han;Hyowon Park;Uk Lee;Hyun Ji Eo
    • Food Science and Preservation
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    • v.30 no.4
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    • pp.562-572
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    • 2023
  • In this study, we aimed to evaluate the quality of Aralia elata shoots according to different packaging methods during storage at 2℃. The highest level of dehydration and wilting incidences were observed in polypropylene containers with polyvinyl chloride wrap (PP+PVC), and these levels continually increased during the entire storage period, compared to other packaging methods. The overall marketability of A. elata shoot packaged in polyethylene terephthalate container (PET) and PP with the mineral-coted functional warp (PP+F) constantly declined during storage with a similar level of 38.6 and 36.0% at 15 days in storage, respectively. PP with PET cover packaging (PP+PET) showed the lowest decay and wilting rates during the entire storage, and the wilting score at 10th day was 51.9, 58.0, 51.8% suppressed, as compared to PET, PP+PVC, and PP+F, respectively. Consequently PP+PET packaging effectively decreased the deterioration of A. elata and maintained marketability for 10 days of storage at 2℃.

The Analysis of Changes in Forest Status and Deforestation of North Korea's DMZ Using RapidEye Satellite Imagery and Google Earth (RapidEye 위성영상과 구글 어스를 활용한 북한 DMZ의 산림현황 및 산림황폐지 변화 분석)

  • KWON, Sookyung;KIM, Eunhee;LIM, Joongbin;YANG, A-Ram
    • Journal of the Korean Association of Geographic Information Studies
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    • v.24 no.4
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    • pp.113-126
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    • 2021
  • This study was conducted to analyze the forest status and deforestation area changes of the DMZ region in North Korea based on satellite images. Using growing and non-growing season's RapidEye satellite images, land cover of the North Korean DMZ was classified into stocking land(conifer, deciduous, mixed), deforested land(unstocked mountain, cultivated mountain, bare mountain), and non-forest areas. Deforestation rates in the Yeonan-baecheon, Beopdong-Pyeonggang, Heoyang-Geumgang and Tongcheon-Goseong district were calculated as 14.24%, 16.75%, 5.98%, and 16.63% respectively. Forest fire and land use change of forest were considered as the main causes of deforestation of DMZ. Changes in deforestation area were analyzed through Google Earth images. As a results, it was shown that the area of deforestation was on a decreasing trend. This study can be used as basic data for establishing inter-Korean border region's forest cooperation strategies by providing forest spatial information on the North Korea's DMZ.

An Analysis of the Correlation between Seoul's Monthly Particulate Matter Concentrations and Surrounding Land Cover Categories (서울시 월별 미세먼지 농도와 주변 토지피복의 관계 분석)

  • Choi, Tae-Young;Kang, Da-In;Cha, Jae-Gyu
    • Journal of Environmental Impact Assessment
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    • v.28 no.6
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    • pp.568-579
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    • 2019
  • The present study aims to identify the effect of land cover categories on particulate matter (PM) concentrations by analyzing the correlation between monthly PM concentrations in Seoul's air quality monitoring network and the percentages of land cover categories by buffers around air quality monitoring stations. According to a monthly correlation analysis between land cover categories and PM concentrations, in the buffer 3km, PM10 showed a better correlation than PM2.5, there was a clear negative correlation with the forest area, the grassland and the urbanized area had some positive correlation with PM10, and the barren land and the urbanized area had some positive correlation with PM2.5. According to a monthly correlation analysis of dominant land cover sub-categories and sub-sub-categories within the buffer 3km, PM10 showed a clear negative correlation with the broad-leaved forest, and some positive correlation with the road was dominant. PM2.5 showed partly negative correlation with the broad-leaved forest and partly positive correlation with the commercial area. There was a very low or no correlation with other grassland and bare land subcategories. A monthly stepwise regression analysis on noticeable land cover sub-categories and sub-sub-categories with positive or negative correlations revealed that an increasing percentage of the broad-leaved forest had a clear effect on reducing PM10 concentrations, and the road was excluded from the selected variables. Although an increasing percentage of the commercial area had some effect on increasing monthly PM2.5 concentrations and an increasing percentage of the broad-leaved forest had an effect on decreasing the PM2.5 concentrations, their effect size was smaller than that on PM10. The forest area around the city center had the largest and clearest effect on reducing PM concentrations. The urbanized area's sub-categories and sub-sub-categories were also confirmed to have some effect on increasing PM concentrations.

A Study of Vegetation Establishment on Denuded Forest Land (황폐나지(荒廢裸地) 지피식생(地被植生) 조성(造成)에 관한 연구(硏究))

  • Lee, Soo Wook
    • Journal of Korean Society of Forest Science
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    • v.31 no.1
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    • pp.37-42
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    • 1976
  • In this study, an effort was made to find out more effective methods for vegetation establishment on denuded forest land along Cheon Bo Mountains, This area has serious sheet erosion as a major erosion process and parent material is granite gneiss which is known as one of the most erosive materials. Lespedeza bicolor, Arundinella hirta and Robinia pseudoacacia were used as ground cover species. Seeding methods were open broadcast seeding and broadcast seeding with straw mulch, dill seeding with 10cm and 20cm width, and spot seeding with 20cm and 30cm diameter. 1. On slopes less than 30 degrees, broadcast seeding method with straw mulch was the most effective way to establish vegetation cover. 2. On steep slopes more than 30 degrees, 10cm drill seeding method was more effective than the other methods. 3. Soil Texture has an influence on vegetation establishment governing soil moisture condition. Coverage and fresh weight were increased with the fine material qantity in soil. 4. In process of year, coverage was increased with fresh weight. On the other hand, survival decreased.

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A Study on a Comparison of Sky View Factors and a Correlation with Air Temperature in the City (하늘시계지수 비교 및 도시기온 상관성 연구: 강남 선정릉지역을 중심으로)

  • Yi, Chaeyeon;Shin, Yire;An, Seung Man
    • Atmosphere
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    • v.27 no.4
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    • pp.483-498
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    • 2017
  • Sky view factor can quantify the influence of complex obstructions. This study aims to evaluate the best available SVF method that represents an urban thermal condition with land cover in complex city of Korea and also to quantify a correlation between SVF and mean air temperature; the results are as follows. First, three SVF methods comparison result shows that urban thermal study should consider forest canopy induced effects because the forest canopy test (on/off) on SVF reveals significant difference range (0.8, between maximum value and minimum value) in comparison with the range (0.1~0.3) of SVFs (Fisheye, SOLWEIG and 3DPC) difference. The significance is bigger as a forest cover proportion become larger. Second, R-square between SVF methods and urban local mean air temperature seems more reliable at night than a day. And as the value of SVF increased, it showed a positive slope in summer day and a negative slope in winter night. In the SVF calculation method, Fisheye SVF, which is the observed value, is close to the 3DPC SVF, but the grid-based SWG SVF is higher in correlation with the temperature. However, both urban climate monitoring and model/analysis study need more development because of the different between SVF and mean air temperature correlation results in the summer night period, which imply other major factors such as cooling air by the forest canopy, warming air by anthropogenic heat emitted from fuel oil combustion and so forth.

Vegetation Structure at the Slope Direction and Characteristic of Seedlings of Abies koreana in Hallasan Mountain (한라산 구상나무림의 사면별 식생구조와 치수발생 특성)

  • Song, Kuk-Man;Kang, Young-Je;Hyeon, Hwa-Ja
    • Journal of Environmental Science International
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    • v.23 no.1
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    • pp.39-46
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    • 2014
  • This study surveyed Abies koreana to identify the correlation between its vegetation structure according to its slope direction and seedling establishment in a bid to build basic research data on the changes and conservation of the A. koreana in Hallasan Mountain. The findings of its vegetation structure revealed that in both areas, Importance value was given to the A. koreana for its tree layer, the Taxus cuspidata for its shrub layer, and the Sasa quelpaertensis for its herb layer. However, in the Youngsil area with the tree layer, high importance was given to deciduous broad-leaved trees such as Prunus maximowiczii, Quercus mongolica, and the young species of the A. koreana in the shrub layer that can maintain the A. koreana forest's greater importance in the Jindallebat than in the Youngsil. Thus, the A. koreana forest in the Jindallebat is believed to lastlonger. The findings of correlation between the quantity of seedlings and their location by area revealed that in each tiny quadrat, the A. koreana seedling averaged 5.3 in the Youngsil and 2.9 in the Jindallebat. Both areas were all found to have a positive correlation in terms of rock exposure ratio and dead tree ratio as well as a negative correlation with regard to the cover degree of S. quelpaertensis, the canopy gap, the total vegetation, and the herb layer. It was found that the cover degree of the herb layer in the Youngsil and the S. quelpaertensis in the Jindallebat had the largest impact on the A. koreana seedlings.

Assessment of Forest Vegetation Effect on Water Balance in a Watershed (산림식생에 따른 유역 물수지 영향 평가)

  • Kim, Chu- Gyum;Kim, Nam-Won
    • Journal of Korea Water Resources Association
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    • v.37 no.9
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    • pp.737-744
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    • 2004
  • In this study, to evaluate the effect of forest vegetation on the long-term water balance in a watershed, semi-distributed and physically based parameter model, SWAT was applied to the Bocheong watershed, and the variation of hydrological components such as evapotranspiration, surface flow, lateral flow, base flow, and total runoff was investigated with coniferous and deciduous forests, respectively. First, SWAT model was modified to simulate the actual plant growth pattern of coniferous trees which have the uniform value of leaf area index all the seasons of the year. The modified model was applied to the watershed that is assumed to have only one land cover in the whole watershed, and the variation of the water balance components was investigated for each land cover. It was found that coniferous forest affected the increase in evapotranspiration and decrease in runoff more than deciduous forest. However, the age and the density of stand, the location, and soil characteristics and meteorological conditions including the tree species should be also considered to examine the effect more quantitatively and to reduce the uncertainties in simulated output from the hydrological model.

Classification of the damaged areas in the DMZ (demilitarized zone) using high-resolution satellite images and climate and topography data (고해상도 위성영상 및 기후·지형 데이터를 이용한 DMZ 불모지의 유형화)

  • Lee, Ah-Young;Shin, Hyun-Tak;Bak, Gi-Ppeum;Jung, Ji-Young;Sung, Chan-Yong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.1
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    • pp.1-14
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    • 2020
  • In this study, we 1) identified the damaged areas along the south limit line (SLL) of the demilitarized zone (DMZ) by the military's 'DMZ barren land campaign', and 2) categorized the identified damaged areas into a few ecological types. Using high-resolution satellite images, we delineated the total damaged areas to be 1,183.2 ha, which accounted for 50.1% of the 100-m northern buffer regions from the SLL. Of the total damaged areas, 16% were severely damaged, i.e., they had been damaged until recently and so remained barren without vegetation cover. In other areas, the levels of damage were either moderate (59.9%) or slight (24.1%), due to natural succession that turned those areas to grassland or forest. Using satellite image-derived land cover maps and climatic and topographic data, we categorized the damaged areas into seven types: lowland grassland (19.8%), western lowland forest (21.4%), low-altitude forest (25.5%), mid-altitude forest (18.4%), high-altitude forest (6.8%), vicinity in east coast (7.9%), and waterbody (0.2%). These types can be used to identify proper measures to restore ecosystems in the DMZ for now and after Korean reunification.

Analysis of Forest Cover Information Extracted by Spectral Mixture Analysis (분광혼합분석 기법에 의한 산림피복 정보의 특성 분석)

  • 이지민;이규성
    • Korean Journal of Remote Sensing
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    • v.19 no.6
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    • pp.411-419
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    • 2003
  • An area corresponding to the spatial resolution of optical remote sensor imagery often includes more than one pure surface material. In such case, a pixel value represents a mixture of spectral reflectance of several materials within it. This study attempts to apply the spectral mixture analysis on forest and to evaluate the information content of endmember fractions resulted from the spectral unmixing. Landsat-7 ETM+ image obtained over the study area in the Kwangneung Experimental Forest was initially geo-referenced and radiometrically corrected to reduce the atmospheric and topographic attenuations. Linear mixture model was applied to separate each pixel by the fraction of six endmember: deciduous, coniferous, soil, built-up, shadow, and rice/grass. The fractional values of six endmember could be used to separate forest cover in more detailed spatial scale. In addition, the soil fraction can be further used to extract the information related to the canopy closure. We also found that the shadow effect is more distinctive at coniferous stands.