• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 1995.12a
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• pp.22-32
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• 1995

The purpose of this study is to estimate not only the watershed soil loss but also its temporal changes of Kyungan River basin, the study area, due to the land development. To analyze the soil loss of the river basin, USLE was employed. GIS and remote sensing were also utilized to estimate the soil loss. The data for this analysis consist of a series of thematic map and remotely sensed data. The remotely sensed images for this study are Landsat TM(Oct, 28, 1997 & Sep. 22, 1992), In Kyungan River basin, not only the detection of temporal changes of land use and GVI, but also the estimation of soil loss provided very significant factors that affect to the watershed environment quality. The management of the factors of vegetative cover, slope steepness and length were the keys to reduce soil loss and solve conservation and protection issues of Kyungan River basin. GIS application with USLE to the watershed analysis allows the planner to recognize sensitive sites and to plan strategies to minimize soil loss.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.981-996
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• 2018

In agriculture, remote sensing data using earth observation satellites have many advantages over other methods in terms of time, space, and efficiency. This study analyzed the changes of reflectance and vegetation index according to atmospheric correction of images before using satellite images in agriculture. Top OF Atmosphere (TOA) reflectance and surface reflectance through atmospheric correction were calculated to compare the reflectance of each band and Normalized Vegetation difference Index (NDVI). As a result, the NDVI observed from field measurement sensors and satellites showed a higher agreement and correlation than the TOA reflectance calculated from surface reflectance using atmospheric correction. Comparing NDVI before and after atmospheric correction for multi-temporal images, NDVI increased after atmospheric corrected in all images. garlic and onion cultivation area and forest where the vegetation health was high area NDVI increased more 0.1. Because the NIR images are included in the water vapor band, atmospheric correction is greatly affected. Therefore, atmospheric correction is a very important process for NDVI time-series analysis in applying image to agricultural field.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.189-193
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• 2008

본 연구는 충주댐 유역을 대상으로 미래의 기후변화, 그에 따른 식생상태, 그리고 미래의 토지이용 변화를 고려한 상태에서 SWAT-K 모형에 의한 수문순환인자들의 변화가 댐의 유입량에 미치는 영향을 파악하고자 한다. SWAT 모형의 검보정은 6년간($2000{\sim}2006$, 2001년 제외)의 댐유입량 자료를 이용하여 실시하였으며, Nash_Sutcliffe 모형효율은 $0.52{\sim}0.88$의 범위로 검보정되었다. 기후변화 시나리오는 IPCC에서 제공하고 있는 GCM들 중에서 CCCma CGCM2의 A2, B2 시나리오를 이용하였으며, 댐유역의 기후변화를 모의하기 위하여 과거 30년간($1977{\sim}2006$)의 기상자료 통계정보를 기준으로 Change Factor Downscaling 기법을 적용하여 2030년, 2060년, 2090년 전후의 각 30년간의 미래 정보를 재생산하였다. 미래의 식생정보는 7년($2000{\sim}2006$)간의 MODIS 위성 영상에 의한 엽면적 지수를 월단위로 구축하여 엽면적 지수와 평균기온간의 상관회귀식을 도출하여 미래 기후변화에 따른 식생의 활력도를 예측하였다. 미래의 토지이용 변화는 CA-MArkov 기법을 개선, 적용하여 총 9개의 토지이용 항목에 대하여 각 항목별 예측을 실시하였다. 2000년의 기상자료 및 댐유입량을 기준으로 이상의 미래기후, 식생, 토지이용 에측 정보를 적용하여 미래의 댐유입량을 모의한 결과를 분석하였다. 그 결과 강수량 및 온도의 변동이 가장 크게 영향을 주어 유입량의 변화가 모의되었으며, 이에 따른 수문인자의 변동은 2000년 기준으로 증발산량, 토양수분의 변동을 분석하였다. 미래의 수문순환에 가장 큰 영향을 주는 수문인자는 토양수분으로 나타나, 미래에는 산림지역 및 토지이용 개발에 따른 토양수분의 함양량 유지를 위한 유역관리가 중요한 요인이 될 것으로 나타났다.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.5
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• pp.8-18
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• 2012

Urban nature plays an important role not only in the improvement of the physical environment but also from the perspective of psychological and social function. In particular, schoolyards as well as the green spaces near school surroundings function as a primary space for urban children to experience nature in Korea, as they spend most of their time at school. In this study, the status of urban green spaces near school surroundings was examined. For the analysis, 185 elementary schools in Seoul were selected and the green spaces within a radius of 300m(defined as 'school zone' in this study) were analyzed using the Rapid Eye multispectral satellite image data. The mean green space ratio of school zone accounts to about 21% with a high variation from 74% to 0.7% and more than half of the school zone have a green space ratio of less than 20%. Schools with a high green space ratio in their school zone are mostly located near urban forests, so forest areas particularly contribute to increase the green space ratio. Furthermore, forest vegetation shows relatively higher vitality than other green spaces located in urbanized areas. In contrast, schools with a low green space ratio in their school zone are mostly situated in high-density residential areas and the green spaces show relatively low vegetation vitality. Except for the urban forest, the majority of urban green spaces in urbanized areas are landscape green facilities in apartment districts. The other types of urban open spaces such as environmentally shaped schoolyards or street parks account only for a very small proportion of school surroundings. Therefore, it is needed to establish countermeasures in the context of urban planning; e.g. to promote the school forest projects preferentially by selecting schools with a extremely low green space ratio in their school zone, to foster roof greening in near surroundings, and to connect schoolyards organically with nearby apartment landscape green facilities as an easily accessible urban open space.

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.14-19
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• 2008

소나무 재선충에 감염되어 고사하는 소나무의 증가는 우리나라 산림에 심각한 위협이 되고 있다. 재선충은 매개 후 고사단계에 이르기까지 진행과 확산이 빨라 감염목이 발견되면 곧바로 임내에서 벌채 및 훈증 처리해야 하며 5${\sim}$6월에 감염되어 10${\sim}$11월에 육안으로 고사를 확인할 수 있다. 재선충에 의해 소나무가 고사되는 과정에서 식생활력도가 크게 감소하며 이러한 현상은 근적외선 영역에서 분광반사의 감소를 수반한다. 따라서 본 연구는 근적외선영역의 분광감소를 이용하여 재선충 피해목의 조기진단이 가능할 수 있다는 것에 착안하여 수행하였다. 근적외선영상 취득 방법으로 휴대가 간편한 근적외선 카메라를 이용하여 재선충 피해지역의 소나무림을 5월부터 11월까지 매월 촬영하였다. 이렇게 수집된 분광반사값으로부터 식생지수(Vegetation Index: VI)의 변화를 분석하였고, VI의 감소율로부터 소나무 재선충 감염목을 조기에 발견할 수 있다는 결과를 도출하였다.

• Journal of Korean Society of Forest Science
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• v.83 no.4
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• pp.460-472
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• 1994

This study has been conducted to give some ideas for reasonable ecological management of Taejon city and its adjacent forest ecosystem against the effect of acid rain. Rain monitoring points to analyse its components represented 1 point in industrial area, 4 points in commercial area, 4 points in residential area, and 5 points in suburban area and forest survey was done in 7 forest sites adjacent to rain monitoring points. Transformed vegetation index(TVI) based on Landsat TM data was analysed for forest area. Taejon area was seriously contaminated by air pollutants and average concentration of anions in precipitation were 20.16mg/l for $SO_4{^{2-}}$, 3.65mg/l for $NO_3{^-}$, and 3.09mg/l for $Cl^-$. Anion in precipitation were $1.09mg/m^2/month$ for $SO_4{^{2-}}$, $0.23mg/m^2/month$ for $NO_3{^-}$, and $0.20mg/m^2/month$ for $Cl^-$. Cation in precipitation were $0.14mg/m^2/month$ for $Ca^{2+}$, $0.10mg/m^2/month$ for $NH_4{^+}$, $0.08mg/m^2/month$ for $Na^+$, $0.07mg/m^2/month$ for $K^+$, and $0.08mg/m^2/month$ for $Mg^{2+}$. The region with the highest concentration of $SO_4{^{2-}}$, $NO_3{^-}$, and $Cl^-$ in rain was industrial area. $SO_4{^{2-}}$, $NO_3{^-}$, and $Cl^-$ concentrations in industrial area were 43.08, 3.88, and 3.64ppm, respectively. Forest soil showed strongly acidic ranging pH4.16-4.94. Transformed vegetation index(TVI) were 3.11 in Dangsan, 4.00 in Kyechoksan, 4.13 in Bomunsan, 4.18 in Kabhasan, 3.34 in Bongsan, 4.13 in Sikchangsan, and 4.20 in Seongchisan. Dangsan forest located near in industrial area showed the lowest TVI.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.4
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• pp.24-34
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• 2002

The purpose of this study is to estimate the ecological effect of DMZ for development and conservation of this area. Because of the political reason, field research and estimation of the ecological effect using field data is very difficult. Then we carried out the estimation of the ecological effect using Landsat ETM+ and ancillary data of digital maps. Because of military disturbance and agricultural activity of common people, NDVI of DMZ was very low value except the interior area of DMZ. According to the distance of DMZ, the variance of NDVI didn't show the logistic curve. This result has the reason as follows. The developing force at level plane of west and middle area reached to DMZ and we could concluded in that case of east area had been effect of regular cutting for view.

• Spatial Information Research
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• v.17 no.1
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• pp.117-129
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• 2009

South Korea has been undergoing spring drought periodically and diverse researches using vegetation index have been carried out to monitor spring droughts. The strength of the vegetation index-based drought monitoring is that the monitoring method enables efficient spatio-temporal grasp of changes in drought events. According to the development of low resolution satellite images such as MODIS, which are characterized by outstanding temporal resolution, the use of the method is expected to increase. Drought analysis using vegetation index considered only meteorological factor as a cause that affects vitality of vegetation. But many indirect and direct factors affect vegetation stress, So many uncertainties are involved in such method of analysis. To secure objectivity of drought analysis that uses vegetation index it is therefore necessary to compare the method with most representative drought analysis tools that are used for drought management. In this study, PDSI and SPI which a meteorological drought index that quantifies drought and that is used as a basic index for drought monitoring and MODIS NDVI are compared to propose correlation among them and to show usefulness of drought assessment that uses vegetation index. This study shows changing patterns of NDVI and SPI 6-month are similar and correlation between NDVI and SPI was highest in inland vegetation cover.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.16-28
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• 2013

Recently the various applications and spectral indices development of airborne hyperspectral imagery(A-HSI) has been increased. Especially the vegetation indices (VIs) were used to verify stress and vigor of vegetation. The VIs needs two or more spectral bands selectively to calculate as NIR(near infrared) and red wavelength. The A-HIS has specific band characteristics as narrow, continues and many. The A-HIS has narrow, continues and many specific band characteristics. That could be make it confuse which of bands could be explained for appropriate vegetation characteristics. If the A-HIS bands is not the same the wavelength with VIs' development band setting, then it need a selection adequate for spectral characteristics of target vegetation. Therefore we set 4 substitute bands for NIR and red wavelength respectively and calculated two VIs combined with substitute bands such as NDVI(normalized difference vegetation index) and MSRI(modified simple ratio index). To consider the variation of each VIs, we adapted the image differencing method of change detection technique. Also, we used spectral derivative to identify appropriate bands for spectral characteristics of digital forest cover type map. The result of adequate bands for two VIs selected red #3 as 680.2nm and NIR #2 as 801.7nm. This wavelength was good for any forest type in low variations.

• Korean Journal of Heritage: History & Science
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• v.43 no.1
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• pp.100-117
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• 2010

This study analyzed vegetation structure of natural monuments Koelreuteria paniculata community in search of a conservation and management plan. Plant sociological analysis of Koelreuteria paniculata community indicates that it can be classified into Achyranthes japonica subcommunity and Rhodotypos scandens subcommunity and Trachelospermum asiaticum var. intermedium subcommunity. While Koelreuteria paniculata community of Ahnmyeondo is composed of sub tree layer and herb layer, those of Pohang and Wando are composed of tree layer, Sub tree layer, shrub layer, herb layer. The results of tree vitality analysis showed that those in Ahnmyeondo appeared to be relatively low when compared to those in Pohang and Wando-gun. This can be understood in two different aspects: disease and insects vulnerability due to a relatively simple structure and lack of competitive species, and decreased vitality / natural branch losses due to crown competition arising from high density. The result of soil characteristics analysis showed that soil texture, soil pH, organic matter, $p_2O_5$, exchange positive ion were sufficient for tree growth while total nitrogen was not, so that discretion would be needed for fertilizer application. As there were damages of disease and inscet, but only for 10~15% of the entire area; it still requires consistent preconsideration. The study suggests the management methods for preservation of Koelreuteria paniculata community. First, securing designated areas is necessary in order to minimize environment deterioration due to surrounding development. Especially, for sections with decreased areas, expansion of designated areas through land purchase should also be considered. Second, artificial interference may affect the livestock. Therefore, monitoring of artificial interference is necessary, based on which protection projects must be conducted. Third, from analysis of young plants which influence the maintenance mechanisms of Koelreuteria paniculata community, a decrease compared to the prior year was observed; investigation is needed. Therefore, an active management policy through status examination of livestock such as germination and young plants is necessary.