• Title/Summary/Keyword: LANDSAT 7

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Land Use Change Detection at Kyeryongsan National Park by Using Remote Sensing and Geographical Information Systems (원격탐사와 GIS를 이용한 계룡산국립공원의 토지이용변화)

  • Shin, Jin-Min;Kahng, Byung-Seon;Lee, Kyoo-Seock
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.3
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    • pp.94-101
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    • 2002
  • 국립공원의 뛰어난 경승지와 생태적으로 보존가치가 높은 지역은 다음 세대에게 물려줄 국가의 귀중한 자원으로서 잘 보존되고 관리되어야 하나 한국의 국립공원에서는 공원의 자연환경을 해치는 개발행위가 이뤄졌거나 제안되고 있다. 이러한 개발행위를 효과적으로 평가하기 위해서는 관련 환경자원의 활용이 필요하고 특히 토지이용변화의 파악이 요구되나 한국의 국립공원은 적절한 토지이용도가 결여되어 있다. 그러므로, 본 연구의 목표는 토지이용변화도를 제작하여 향후 국립공원에서 제안되는 개발행위가 해당국립공원의 토지이용변화에 미친 영향을 파악함으로써 국립공원의 환경 및 경관 관리에 기여하는 데에 있다. 본 연구는 계룡산국립공원을 대상으로 1988년도부터 1998년까지의 토지이용변화를 파악하기 위해 원격탐사 자료를 이용하여 2개년도의 Landsat TM 영상을 기하보정하여 토지피복분류를 추출하였다. 이를 바탕으로 항공사진과 현지조사를 통해 확인하여 작성한 토지이용현황도와 토지이용변화도를 GIS에 입력하였으며 GIS의 분석기능을 이용하여 10년간의 토지이용변화에 대해 파악하였다. 토지이용변화 파악 결과, 농지와 나대지가 계룡산국림공원 전체에서 43.7ha, 102.2ha 각각 감소하였고 산림과 개발지는 121.Oha, 24.8ha. 각각 증가하였다. 산림의 증가는 1988년 영상분류당시 산림의 가장자리 유령림이 농경지로 분류되었던 것이 10년 뒤 영상에서는 산림으로 분류된 결과로 파악되며 개발지의 증가는 계룡산국립공원 동학사 제2집단시설지구의 개발로 기존 농경지가 감소, 전용되었고 나대지는 개발로 인해 감소되었다. 개발지의 증가는 취락지구와 집단시설지구에서 두드러졌으며 이들 두 지구에서 산림, 농경지, 나대지 모두 감소하고 대신 개발지가 증가하였다. 본 연구를 수행한 결과 계룡산 국립공원의 가장 큰 토지이용변화는 건물 신축이었으며 이는 집단시설지구의 신설에 기인하고 있다. 취락지구도 개발 행위가 증가하고 있어 집단시설지구와 취락지구의 이용후 평가가 이뤄져야 한다고 생각한다. 본 연구에서 작성한 토지이용변화도는 향후 국립공원의 경관 변화를 파악하는 데에 효과적으로 이용될 수 있다고 판단된다.

Application of Remote Sensing and GIS to Flood Monitoring and Mitigation

  • Petchprayoon, Pakorn;Chalermpong, Patiwet;Anan, Thanwarat;Polngam, Supapis;Simking, Ramphing
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.962-964
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    • 2003
  • In 2002 Thailand was faced with severe flooding in the North, Northeast and Central parts of the country caused by heavy rainfall of the monsoonal depression which brought about significant damages. According to the report by the Ministry of Interior and the Ministry of Agricultural and Co-operatives, the total damages were estimated to be about 6 billion bath. More than 850,000 farmers and 10 million livestock were effected. An area of 1,450,000 ha of farmland in 59 Provinces were put under water for a prolonged period. Satellite imageries were employed for mapping and monitoring the flood-inundated areas, flood damage assessment, flood hazard zoning and post-flood survey of river configuration and protection works. By integrating satellite data with other updated spatial and non-spatial data, likely flood zones can be predicted beforehand. Some examples of satellite data application to flood dis aster mitigation in Thailand during 2002 using mostly Radarsat-1 data and Landsat-7 data were illustrated and discussed in the paper. The results showed that satellite data can clearly identify and give information on the status, flooding period, boundary and damage of flooding. For comprehensive flood mitigation planning, other geo-informatic data, such as the elevation of topography, hydrological data need to be integrated. Ground truth data of the watershed area, including the water level, velocity, drainage pattern and direction were also useful for flood forecasting in the future.

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A Study on Change of Average SCS-CN Value by the Spatial Resolution (공간해상도에 따른 유역평균 SCS-N값 변화에 관한 연구)

  • Chang Eun-Mi;Jung In-Kyun
    • Korean Journal of Remote Sensing
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    • v.20 no.6
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    • pp.361-368
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    • 2004
  • Hydraulic models has a module to calculate SCS-CN values in order to estimate amount of water flow, which can be done with remotely sensed data and GIS data. The choice of the ancillary data tends to determine the range of SCS-CN values. We compare the results of SCS-CN value with satellite data of different spatial resolution and with soil maps of different scale. Mokhyun river basin was chosen,partly because of availbility of water quality and quantity data, partly because of rapid changes in land use and land cover since last ten years. The average CN values were calculated with spatial resolutions of 2.5 meter and 30 meter, We could not find any different result due to spatial resolution of CN resolution but due to both soil maps and to land cover maps. Further studies should be done for more than two kinds of satellite data.

Assessment of Rainfall Runoff and Flood Inundation in the Mekong River Basin by Using RRI Model

  • Try, Sophal;Lee, Giha;Yu, Wansik;Oeurng, Chantha
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.191-191
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    • 2017
  • Floods have become more widespread and frequent among natural disasters and consisted significant losses of lives and properties worldwide. Flood's impacts are threatening socio-economic and people's lives in the Mekong River Basin every year. The objective of this study is to identify the flood hazard areas and inundation depth in the Mekong River Basin. A rainfall-runoff and flood inundation model is necessary to enhance understanding of characteristic of flooding. Rainfall-Runoff-Inundation (RRI) model, a two-dimensional model capable of simulating rainfall-runoff and flood inundation simultaneously, was applied in this study. HydoSHEDS Topographical data, APPRODITE precipitation, MODIS land use, and river cross section were used as input data for the simulation. The Shuffled Complex Evolution (SCE-UA) global optimization method was integrated with RRI model to calibrate the sensitive parameters. In the present study, we selected flood event in 2000 which was considered as 50-year return period flood in term of discharge volume of 500 km3. The simulated results were compared with observed discharge at the stations along the mainstream and inundation map produced by Dartmouth Flood Observatory and Landsat 7. The results indicated good agreement between observed and simulated discharge with NSE = 0.86 at Stung Treng Station. The model predicted inundation extent with success rate SR = 67.50% and modified success rate MSR = 74.53%. In conclusion, the RRI model was successfully used to simulate rainfall runoff and inundation processes in the large scale Mekong River Basin with a good performance. It is recommended to improve the quality of the input data in order to increase the accuracy of the simulation result.

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Satellite-derived high-resolution land cover classification using machine learning techniques: Focusing on inland wetlands in Korea (머신러닝 기법을 활용한 인공위성 자료 기반 고해상도 토지피복 분류: 국내 내륙습지를 중심으로)

  • Beomseo Kim;Seunghyun Hwang;Jeemi Sung;Hyeon-Joon Kim;Jongjin Baik;Changhyun Jun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.423-423
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    • 2023
  • 습지 생태계는 탄소저장고, 대기 온·습도 조절 등의 기능을 수행하는 만큼 면밀한 관리가 요구된다. 습지의 규모와 생태계는 밀접한 연관성을 가지므로 그 규모를 우선적으로 파악할 필요가 있으며, 이를 위해 지표면의 상태를 산지, 습지, 수역 등의 항목으로 구분한 토지피복지도가 고려될 수 있다. 현재, 환경부에서 운영 중인 환경공간정보서비스(https://egis.me.go.kr/)에서는 각각 30 m, 5 m, 1 m의 공간 해상도와 7, 22, 41가지 분류 항목을 갖는 대분류, 중분류, 세분류로 구분된 토지피복지도를 제공하며 이러한 자료들은 모두 1년 이상의 시간 해상도를 갖는다. 습지의 경우, 계절에 따른 환경 변화로 인한 규모의 변동성이 크게 나타날 수 있기 때문에 1년 이하의 시간 해상도를 갖는 고품질 토지피복 분류 정보가 요구된다. 따라서 본 연구에서는 기존 자료의 낮은 시간 해상도 보완을 목표로, 1개월과 30 m의 시·공간 해상도를 갖는 토지피복지도를 구축하기 위한 방법론을 제안하고자 한다. 이를 위해 Landsat-8 등과 같은 다양한 인공위성 자료를 수집하고, Support Vector Machine 등과 같은 머신러닝 기법을 적용하였다. 최종적으로 습지보전법에서 지정한 습지보호지역 중 내륙습지 26개소를 대상으로, 본 연구로부터 산출된 토지피복지도를 기존 환경공간정보서비스 내 대분류 토지피복지도와 비교·평가하였다.

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Simulation Approach for the Tracing the Marine Pollution Using Multi-Remote Sensing Data (다중 원격탐사 자료를 활용한 해양 오염 추적 모의 실험 방안에 대한 연구)

  • Kim, Keunyong;Kim, Euihyun;Choi, Jun Myoung;Shin, Jisun;Kim, Wonkook;Lee, Kwang-Jae;Son, Young Baek;Ryu, Joo-Hyung
    • Korean Journal of Remote Sensing
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    • v.36 no.2_2
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    • pp.249-261
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    • 2020
  • Coastal monitoring using multiple platforms/sensors is a very important tools for accurately understanding the changes in offshore marine environment and disaster with high temporal and spatial resolutions. However, integrated observation studies using multiple platforms and sensors are insufficient, and none of them have been evaluated for efficiency and limitation of convergence. In this study, we aimed to suggest an integrated observation method with multi-remote sensing platform and sensors, and to diagnose the utility and limitation. Integrated in situ surveys were conducted using Rhodamine WT fluorescent dye to simulate various marine disasters. In September 2019, the distribution and movement of RWT dye patches were detected using satellite (Kompsat-2/3/3A, Landsat-8 OLI, Sentinel-3 OLCI and GOCI), unmanned aircraft (Mavic 2 pro and Inspire 2), and manned aircraft platforms after injecting fluorescent dye into the waters of the South Sea-Yeosu Sea. The initial patch size of the RWT dye was 2,600 ㎡ and spread to 62,000 ㎡ about 138 minutes later. The RWT patches gradually moved southwestward from the point where they were first released,similar to the pattern of tidal current flowing southwest as the tides gradually decreased. Unmanned Aerial Vehicles (UAVs) image showed highest resolution in terms of spatial and time resolution, but the coverage area was the narrowest. In the case of satellite images, the coverage area was wide, but there were some limitations compared to other platforms in terms of operability due to the long cycle of revisiting. For Sentinel-3 OLCI and GOCI, the spectral resolution and signal-to-noise ratio (SNR) were the highest, but small fluorescent dye detection was limited in terms of spatial resolution. In the case of hyperspectral sensor mounted on manned aircraft, the spectral resolution was the highest, but this was also somewhat limited in terms of operability. From this simulation approach, multi-platform integrated observation was able to confirm that time,space and spectral resolution could be significantly improved. In the future, if this study results are linked to coastal numerical models, it will be possible to predict the transport and diffusion of contaminants, and it is expected that it can contribute to improving model accuracy by using them as input and verification data of the numerical models.

An Application of Satellite Image Analysis to Visualize the Effects of Urban Green Areas on Temperature (위성영상을 이용한 도시녹지의 기온저감 효과 분석)

  • Yoon, Min-Ho;Ahn, Tong-Mahn
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.3
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    • pp.46-53
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    • 2009
  • Urbanization brings several changes to the natural environment. Its consequences can have a direct effect on climatic features, as in the Urban Heat Island Effect. One factor that directly affects the urban climate is the green area. In urban areas, vegetation is suppressed in order to accommodate manmade buildings and streets. In this paper we analyze the effect of green areas on the urban temperature in Seoul. The period selected for analysis was July 30th, 2007. The ground temperature was measured using Landsat TM satellite imagery. Land cover was calculated in terms of city area, water, bare soil, wet lands, grass lands, forest, and farmland. We extracted the surface temperature using the Linear Regression Model. Then, we did a regression analysis between air temperature at the Automatic Weather Station and surface temperature. Finally, we calculated the temperature decrease area and the population benefits from the green areas. Consequently, we determined that a green area with a radius of 500m will have a temperature reduction area of $67.33km^2$, in terms of urban area. This is 11.12% of Seoul's metropolitan area and 18.09% of the Seoul urban area. We can assume that about 1,892,000 people would be affected by this green area's temperature reduction. Also, we randomly chose 50 places to analysis a cross section of temperature reduction area. Temperature differences between the boundaries of green and urban areas are an average of $0.78^{\circ}C$. The highest temperature difference is $1.7^{\circ}C$, and the lowest temperature difference is $0.3^{\circ}C$. This study has demonstrated that we can understand how green areas truly affect air temperature.

Sensitivity and Self-purification Function of Forest Ecosystem to Acid Precipitation(I) - Acidification of Precipitation and Transformed Vegetation Index(TVI) - (산성우(酸性雨)에 대한 산림생태계(山林生態系)의 민감도(敏感度) 및 자정기능(自淨機能)(I) - 강우(降雨)의 산성화도(酸性化度)와 식생(植生) 활력도(活力度)(TVI)를 중심(中心)으로 -)

  • Lee, Soo Wook;Chang, Kwan Soon
    • 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.

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Change of the Land Use in Yanji city of China in the Connection with Urbanization Process (도시화에 따른 중국 연길시 토지이용의 변화)

  • Li, Mingyu
    • Journal of the Korean association of regional geographers
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    • v.12 no.2
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    • pp.323-337
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    • 2006
  • This thesis aims to study Change of the Land Use in Yanji city since the reformation and opening of China in the Connection with Urbanization Process. This study is based on Landsat image and maps and data related to topography, urban planning basic, the cadastral map were employed. Softwares such as Arcview3.3, ArcGis8.0 were used. The result of the research is as follows. It clearly appears that there have decreased in the ratio of agricultural areas since the increase in other urban usage of land. There has greatly increased in residential, commercial and industrial areas. Such as the capitalist and market economic city the highest point of city land price emerged in downtown of the old city center. In addition spatial pattern of land price is unusually quite different from the western city in its pattern of land price surface declining tendency between the highest land price and the lowest land price. The land price surface shows irregular patterns with increase of distance from downtown due to various urban developments. According to the land price distribution map, it is possible to guess spatial development of the city that the north-eastern part of Yanji was developed prior to south-western area. The center of the city, or downtown expanded to eastward, and the city expanded to south-westward out skirt. Along the main road, Xin-xing areas developed toward east and west ward.

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A Study on the Precise Lineament Recovery of Alluvial Deposits Using Satellite Imagery and GIS (충적층의 정밀 선구조 추출을 위한 위성영상과 GIS 기법의 활용에 관한 연구)

  • 이수진;석동우;황종선;이동천;김정우
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2003.04a
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    • pp.363-368
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    • 2003
  • We have successfully developed a more effective algorithm to extract the lineament in the area covered by wide alluvial deposits characterized by a relatively narrow range of brightness in the Landsat TM image, while the currently used algorithm is limited to the mountainous areas. In the new algorithm, flat areas mainly consisting of alluvial deposits were selected using the Local Enhancement from the Digital Elevation Model (DEM). The aspect values were obtained by 3${\times}$3 moving windowing of Zevenbergen & Thorno's Method, and then the slopes of the study area were determined using the aspect values. After the lineament factors in the alluvial deposits were revealed by comparing the threshold values, the first rank lineament under the alluvial deposits were extracted using the Hough transform In order to extract the final lineament, the lowest points under the alluvial deposits in a given topographic section perpendicular to the first rank lineament were determined through the spline interpolation, and then the final lineament were chosen through Hough transform using the lowest points. The algorithm developed in this study enables us to observe a clearer lineament in the areas covered by much larger alluvial deposits compared with the results extracted using the conventional existing algorithm. There exists, however, some differences between the first rank lineament, obtained using the aspect and the slope, and the final lineament. This study shows that the new algorithm more effectively extracts the lineament in the area covered with wide alluvlal deposits than in the areas of converging slope, areas with narrow alluvial deposits or valleys.

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