• Journal of Practical Agriculture & Fisheries Research
• /
• v.24 no.3
• /
• pp.33-43
• /
• 2022

This study was conducted to monitor the vegetation recovery in the areas damaged by the forest fires on the east coast that occurred in April 2000. The study site was a forest fire-damaged area in Samcheok-si, Gangwon-do, and 21 monitoring areas (12 natural restoration sites, 9 artificial restoration sites) were selected to analyze the vegetation recovery trend since 1998. The vegetation recovery trend was compared by calculating the values according to the year using the difference Normalized Burn Ratio (dNBR) and Normalized Difference Vegetation Index (NDVI) based on satellite images (Landsat TM/ETM+ and Sentinel-2A). As the result of this study, all 21 sites, vegetation was recovered, and both groups showed the greatest recovery in summer. In the case of the dNBR, the artificial restored sites showed higher values than the natural restored sites, and in the case of the NDVI, the natural restored sites were higher than the artificially restored sites in summer and autumn. However, the difference between the two groups of natural and artificial restoration sites was not significant. Therefore, the direction of forest restoration after forest fire damage can be effectively restored if properly implemented for the purpose of restoration of the target site.

• Korean Journal of Remote Sensing
• /
• v.28 no.4
• /
• pp.409-420
• /
• 2012

Since the Industrial Revolution, CO2 levels have been increasing with climate change. In this study, Analyze time-series changes in snow cover quantitatively and predict the vanishing point of snow cover statistically using remote sensing. The study area is Mt. Kilimanjaro, Tanzania. 23 image data of Landsat-5 TM and Landsat-7 ETM+, spanning the 27 years from June 1984 to July 2011, were acquired. For this study, first, atmospheric correction was performed on each image using the COST atmospheric correction model. Second, the snow cover area was extracted using the NDSI (Normalized Difference Snow Index) algorithm. Third, the minimum height of snow cover was determined using SRTM DEM. Finally, the vanishing point of snow cover was predicted using the trend line of a linear function. Analysis was divided using a total of 23 images and 17 images during the dry season. Results show that snow cover area decreased by approximately $6.47km^2$ from $9.01km^2$ to $2.54km^2$, equivalent to a 73% reduction. The minimum height of snow cover increased by approximately 290 m, from 4,603 m to 4,893 m. Using the trend line result shows that the snow cover area decreased by approximately $0.342km^2$ in the dry season and $0.421km^2$ overall each year. In contrast, the annual increase in the minimum height of snow cover was approximately 9.848 m in the dry season and 11.251 m overall. Based on this analysis of vanishing point, there will be no snow cover 2020 at 95% confidence interval. This study can be used to monitor global climate change by providing the change in snow cover area and reference data when studying this area or similar areas in future research.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.10 no.3
• /
• pp.80-92
• /
• 2007

Forest fire is the dominant large-scale disturbance mechanism in the Korean temperate forest, and it strongly influences forest structure and function. Moreover burn severity incorporates both short- and long-term post-fire effects on the local and regional environment. Burn severity is defined by the degree to which an ecosystem has changed owing to the fire. Vegetation rehabilitation may specifically vary according to burn severity after fire. To understand burn severity and process of vegetation rehabilitation at the damaged area after large-fire is required a lot of man powers and budgets. However the analysis of burn severity in the forest area using satellite imagery can acquire rapidly information and more objective results remotely in the large-fire area. Space and airbone sensors have been used to map area burned, assess characteristics of active fires, and characterize post-fire ecological effects. For classifying fire damaged area and analyzing burn severity of Samcheok fire area occurred in 2000, Cheongyang fire in 2002, and Yangyang fire in 2005 we utilized Normalized Burn Ratio(NBR) technique. The NBR is temporally differenced between pre- and post-fire datasets to determine the extent and degree of change detected from burning. In this paper we use pre- and post-fire imagery from the Landsat TM and ETM+ imagery to compute the NBR and evaluate large-scale patterns of burn severity at 30m spatial resolution. 65% in the Samcheok fire area, 91% in the Cheongyang fire area and 65% in the Yangyang fire area were corresponded to burn severity class above 'High'. Therefore the use of a remotely sensed Differenced Normalized Burn Ratio(${\Delta}NBR$) by RS and GIS allows for the burn severity to be quantified spatially by mapping damaged domain and burn severity across large-fire area.

• Journal of the Korean Geographical Society
• /
• v.38 no.4
• /
• pp.630-639
• /
• 2003

This study aims to analysis the distribution and change of cropland and forest, the Onseong, Saebyeol, and Eundeok counties on the lower reach of Duman(Tumen) river, northeast Korea, using 1992 year Landsat TM data, 2000 year Landsat ETM data, and digital terrain elevation data(DTED). Land cover and land use of the study areas are classified into cropland, forest, village, and water body, using the supervised classification method including 1:50,000 DTED analysis, image band composition, and principal component analysis(PCA). Results of quantitative analysis present that each growth rate of cropland of Onseong and Eundeok are 22.8% and 14.7% corresponding to decreasing rates of forest, 8% and 13.6% during 8 years from 1992 to 2000. In Onseong, Saebyeol, and Eundeok, each values of mean elevations and slope gradients increased to 192m, 95m, and 91m from 157m, 85m, and 78m, and to 6.6$^{\circ}$, 3.0$^{\circ}$, and 4.4$^{\circ}$ from 5.2$^{\circ}$, 2.5$^{\circ}$, and 3.0$^{\circ}$. Especially, in case of newly developed cropland, the values of mean elevation and mean gradient have 225m, 122m, and 127m, and 9.4$^{\circ}$, 5.1$^{\circ}$, and 8.0$^{\circ}$, in above three regions. These new croplands were developing along to deeper valleys and toward lower hill and mountain slope up to knickpoint zone of gradient change. Deforested lands for cropland have formed irregular pattern of patch-type, and become sources for the sheet erosion, rilling and gulleying in mountain slope and sedimentation in local river channel. Though there were no field checking, analysis using landsat images and GIS mapping can help understand actual environmental problems relating to cropland development of mountain slope in North Korea.

• Journal of the Korean association of regional geographers
• /
• v.9 no.3
• /
• pp.373-384
• /
• 2003

This study analyses the soil loss due to cropland increase in the Hoeryeung area of northeast Korea, using Landsat images of 1987 TM and 2001 ETM, together with DTED, soil and geological maps, and rainfall data of 20 years. Items of land cover and land use were categorized as cropland, settlement, forest, river zone, and sand deposit by supervised classification with spectral bands 1, 2 and 3. RUSLE model is used for estimation of soil loss, and AML language for calculation of soil loss volumes. Fourier transformation method is used for unification of the geographical grids between Landsat images and DTED. GTD was selected from 1:50,000 topographic map. Main sources of soil losses over 100 ton/year may be the river zone and settlement in the both times of 1987 and 2001, but the image of the 2001 shows that sources areas have developed up to the higher mountain slopes. In the cropland average, increases of hight and gradient are 24m and $0.8^{\circ}$ from 1987 to 2001. In the case of new developed cropland, average increases are 75m and $2.5^{\circ}$, and highest soil loss has occurred at the elevation between 300 and 500m. The soil loss 57 ton of 1987 year increased 85 ton of 2001 year. Soil loss is highest in $30{\sim}50^{\circ}$ slope zones in both years, but in 2001 year, soil loss increased under $30^{\circ}$ zones. The size of area over 200 ton/year, indicating higher risk of landslides, have increased from $28.6km^2$ of 1987 year to $48.8km^2$ of 2001 year.

• Korean Journal of Remote Sensing
• /
• v.34 no.6_2
• /
• pp.1165-1178
• /
• 2018

Collapse of an Antarctic ice shelf and its flow velocity changes has the potential to reduce the restraining stress to the seaward flow of the Antarctic Ice Sheet, which can cause sea level rising. In this study, variations in ice velocity from 2000 to 2017 for the Nansen Ice Shelf in East Antarctica that experienced a large-scale collapse in April 2016 were analyzed using Landsat-7 Enhanced Thematic Mapper Plus (ETM+) and Landsat-8 Operational Land Imager (OLI) images. To extract ice velocity, image matching based on orientation correlation was applied to the image pairs of blue, green, red, near-infrared, panchromatic, and the first principal component image of the Landsat multispectral data, from which the results were combined. The Landsat multispectral image matching produced reliable ice velocities for at least 14% wider area on the Nansen Ice Shelf than for the case of using single band (i.e., panchromatic) image matching. The ice velocities derived from the Landsat multispectral image matching have the error of $2.1m\;a^{-1}$ compared to the in situ Global Positioning System (GPS) observation data. The region adjacent to the Drygalski Ice Tongue showed the fastest increase in ice velocity between 2000 and 2017. The ice velocity along the central flow line of the Nansen Ice Shelf was stable before 2010 (${\sim}228m\;a^{-1}$). In 2011-2012, when a rift began to develop near the ice front, the ice flow was accelerated (${\sim}255m\;a^{-1}$) but the velocity was only about 11% faster than 2010. Since 2014, the massive rift had been fully developed, and the ice velocity of the upper region of the rift slightly decreased (${\sim}225m\;a^{-1}$) and stabilized. This means that the development of the rift and the resulting collapse of the ice front had little effect on the ice velocity of the Nansen Ice Shelf.

• Korean Journal of Remote Sensing
• /
• v.29 no.2
• /
• pp.197-207
• /
• 2013

Difficulties of emissivity determination and atmospheric correction degrade the estimation accuracy of land surface temperature (LST). That is, since the emissivity determination of land surface material and the correction of atmospheric effect are not perfect, it is very difficult to estimate the precise LST from a thermal infrared image such as Landsat TM and ETM+, ASTER, etc. In this study, we propose an efficient method to estimate land surface temperature difference (LSTD) rather than LST from Landsat thermal band images. This method is based on the assumptions that 1) atmospheric effects are same over a image and 2) the emissivity of vegetation region is 0.99. To validate the performance of the proposed method, error sensitive analysis according to error variations of reference land surface temperature and the water vapor is performed. The results show that the estimated LSTD have respectively the errors of ${\pm}0.06K$, ${\pm}0.15K$ and ${\pm}0.30K$ when the water vapor error of ${\pm}0.302g/cm^2$ and the radiance differences of 0.2, 0.5 and $1.0Wm^{-2}sr^{-1}{\mu}m$ are considered. And also the errors of the LSTD estimation are respectively ${\pm}0.037K$, ${\pm}0.089K$, ${\pm}0.168K$ in the reference land surface temperature error of ${\pm}2.41K$. Therefore, the proposed method enables to estimate the LSTD with the accuracy of less than 0.5K.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.09a
• /
• pp.253-256
• /
• 2002

거제도는 남쪽에서 두 번째로 큰 섬으로써 총면적은 399.96$\textrm{km}^2$이며 총면적의 71.85%가 임야로 이루어져 있고 하천이 짧으며 유역면적이 좁은 관계로 지하수의 함양이 어려우며 해안으로 유출되는 지하수가 상당량이 될 것으로 사료되었다. 따라서 유출지하수의 특성을 연구하여 지하수의 유출가능성이 높은 지역을 찾을 수 있도록 여러 가지 분석을 통하여 알아보았다. 이를 위하여 기본적으로 기온, 강수량 등의 기상자료와 지하수온도, 지하수위등의 수문자료 및 해수표면온도 등의 해양관측자료를 이용하였으며, 해수와 지하수의 온도차가 많은 달의 Lanset 7 ETM+ 인공위성 영상자료와 NOAA 인공영상자료를 이용하여 온도자료를 비교하고, 각개 영사의 열분포도를 분석함으로써 유출지하수의 가능성이 높은 지역을 추출하였다. 추출한 지역에서 인구밀집지역, 공단지역, 기 공급지역을 제외하였으며, 수문지질학 적으로 유리한 지역을 선정하고, 평균해수분포차가 큰 지역을 추출함으로써 이후에 이루어질 현장조사시에 접근이 용이하도록 하였다. 연구결과 거제도 일대의 해안유출지하수 가능지점은 10개소 이상이며 자연적, 사회학석인 여건을 고려한다면 지하수개발가능 지역은 6개 정도로 예상된다. 또한 해수면의 온도와 지하수의 온도가 차이가 클 때는11~13$^{\circ}C$의 분포를 보이고 있어, 이후 이와 같은 연구에 충분히 활용할 수 있을 것이며, 해상도가 높은 자료와 연계하면 보다 정확한 자료의 추출이 가능해 앞으로의 국내에 활용되지 못한 수자원 개발에도 많은 도움이 될 것으로 판단된다.하게도 유기물과의 친화력이 높은 것으로 알려진 Cu 역시 F1과 F2에 대하여 높은 함량을 나타내어 오염원으로부터의 Cu의 확산을 지시하였다. 외국에 비하여, 그동안 국내에서는 사격장 주변의 자연환경변화에 관하여 연구된 결과가 거의 전무하였다. 본 연구 결과는, 이와 유사한 사격장 주변 환경에서의 중금속 분포와 거동 특성에 대하여 종합적인 모니터링(즉, 체계적인 환경지구화학적 조사ㆍ연구)이 시급함을 시사해 주고 있다.할 수 있었다.연구지역을 대상으로 추정한 함양율은 지하수이용에 따른 지하수위하강에 대한 보정을 할 필요가 있으며 지하수이용실태조사를 추가로 하여 그 이용량만큼을 지하수함양량에 더하여야 할것이다.의 특성 등을 고려하여 거기에 맞는 기술들을 복합적으로 또는 단독으로 사용하되 처리방법 채택 시 신중을 기할 것이 요망된다.정시에는 SeaWiFS 위성과 관련된 global algorithms 중에서 490nm와 555nm의 복합밴드를 포함하는 OC2 알고리즘(ocean color chlorophyll 2 algorithm)을 사용하는 것이 OC2 series 및 OC4 알고리즘보다 좋은 추정 값을 도출할 수 있을 것으로 기대된다.환경에서는 5일에서 7월에 주로 이 충체의 유충이 발육되고 전파되는 것으로 추측되었다.러 가지 방법들을 적극 적용하여 금후 검토해볼 필요가 있을 것이다.잡은 전혀 삭과가 형성되지 않았다. 이 결과는 종간 교잡종을 자방친으로 하고 그 자방친의 화분친을 사용할 때만 교잡이 이루어지고 있음을 나타내고 있다. 따라서 여교잡을 통한 종간잡종 품종육성 활용방안을 금후 적극 확대 검토해야 할 것이다하였다.함을 보

• Proceedings of the Korean Society for the Gifted Conference
• /
• 2003.11a
• /
• pp.185-186
• /
• 2003

영재교육 프로그램 개발의 핵심적인 부분은 영재들에게 적절한 교육과정이며, 대표적인 영재교육과정모형으로 삼부심화학습모형(Enrichment Triad Model: ETM), 학교단위 심화학습모형(Schoolwide Enrichment Model： SEM), 자기주도적 학습모형 (Self-Directed Learning Model), 퍼듀 3단계 심화학습 모형(Purdue Three-Stage Enrichment Model) 등이 있다. 이들 모형에 대한 적용 연구가 일부 초등학교냐 중학교의 시범적인 속진 및 심화 프로그램 실시로 적용된 바는 있으나 정규 교육과정에서는 실시될 기회가 없었다. 국내에서도 2002년 영재교육법 시행령 적용 이후 과학영재학교가 지정되어 운영되고 있기에, 영재교육을 위한 모형을 정규 교육과정 및 교수-학습 과정에 적용하고 그 효과를 밝히는 연구가 필요하다. 이에 본 연구에서는 삼부심화학습모형을 적용하기 위한 구체적인 교수·학습 과정안을 개발하고, 이를 과학영재학교 물리수업에 적용하여 그 과정과 학생들의 인식을 분석하고자 한다. 본 연구의 대상은 과학영재고등학교 1학년 72명이며 검사결과 지능지수, 추리력, 수리력, 지각력 면에서 매우 우수한 집단으로 나타났다. 삼부심화학습모형을 실시한 기간은, 1단계 활동을 2주간 실시하였고, 2단계 활동은 4개월간 진행하고 있으며, 3단계 활동은 겨울방학을 이용하여 실시할 계획이다. 삼부심화학습모형에 의하면 1단계는‘일반 탐색 활동을 통한 심화 학습’단계로 정규 교육과정 속에 포함되어 있지 않은 새롭고, 흥미로운 주제나 지식 영역들에 학생들이 접할 수 있도록 설계된 일반적 탐구 혹은 탐색 경험들을 제공하는 것으로 구성된다. 점수를 종속변인으로 하여 회귀분석을 한 결과 TTCT 도형과 언어 검사 모두 WAIS 소검사중의 기본지식문제가 TTCT 전체점수에 가장 높은 영향력을 미쳤다. 지능이 높은 그룹과 낮은 그룹에 대해 WAIS 11개 소검사와 TTCT 전체점수와의 상관을 구한 결과, 지능이 높은 그룹에서는 유의미한 상관을 의미는 소검사가 거의 없었던 것과는 달리, 지능이 낮은 그룹에서는 결정성지능을 대표하는 소 검사와 TTCT 도형검사 점수간의 상관이 유의미하게 나타났다. 이상의 결과를 통해 TTCT는 도형과 언어 검사 모두 유동성지능 보다는 결정성지능과 상관이 있음을 알 수 있는데, 이는 창의력 검사가 문제 해결 상황에 기존의 지식을 이용하는 능력을 측정하고 있기 때문으로 추정된다. 또한 지능이 낮은 그룹에서 높은 그룹에 비해 창의력 검사와 지능 검사 사이의 상관의 정도가 높았는데, 이는 일정 수준까지는 창의적 능력이 결정성 지능에 의해 제한을 받으나 일정 수준 이상의 결정성 지능을 갖게 되면 더 이상 결정성 지능이 창의적 능력을 제한하지 않기 때문인 것으로 해석된다.circ}C$에서 2.5~8.2mg$CO_2$/kg.hr로 일반적으로 보고되고 있는 토마토 호흡속도와 일치하는 결과를 나타내었다.다.환원당인 sucrose 함량은 계속 증가하였고 fructose, glucose, sorbitol의 함량(추황의 sorbitol을 제외)은 생장이 촉진됨에 따라 증가하다가 다시 점차적으로 감소하였다. 이러한 결과는 총당과 환원당의 측정결과와 일치한 것으로 나타났다. 결론적으로 배의 성장에 따라 산 함량은 감소하였고 당 함량은 증가하였다.luco-pyranoside, quercetin 7-O

• Journal of the Korean Geographical Society
• /
• v.41 no.3 s.114
• /
• pp.331-345
• /
• 2006

This study deals with geomorphological process of the sand dune landform including the distribution and surface environments, characteristics of sediments, origins and moving processes in lower reach and mouth delta of Duman River, Northeast Korea and China. The methodology of the study includes image analysis of Landsat TM(1992.10) and ETM(2000.9) and Spot(2005.4) for analysis of land cover, 2 times field survey for recognition of landform and acquisition of sediments raw data materials, and grain analysis and exoscopy about raw data materials. The geomorphic elements from satellite image analysis are composed of the delta, sand spit, active and stable dune, sand bar and riparian vegetated zone. Results of the grain analysis indicate the sediments originated from marine coastal zone than riverine one. This means that present sand dune not so much reflect present climatic and geomorphic environments. Result of the exoscopy analysis show that ratio of quartz, which is comparatively resistant to environment, is highest as $65{\sim}83%$ out of sediments. But the surface of the $30{\sim}40%$ of mineral grains was coated by yellow-colored stained materials, due to chemical weathering. Some grains show rough skin, looking as acicular, network structure and etching pits, affected by physical and chemical weathering.