• Title/Summary/Keyword: land classification

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Estimation of soil moisture based on Sentinel-1 SAR data: Assessment of soil moisture estimation in different vegetation condition (Sentinel-1 SAR 토양수분 산정 연구: 식생에 따른 토양수분 모의평가)

  • Cho, Seongkeun;Jeong, Jaehwan;Lee, Seulchan;Choi, Minha
    • Journal of Korea Water Resources Association
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    • v.54 no.2
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    • pp.81-91
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    • 2021
  • Synthetic Apreture Radar (SAR) is attracting attentions with its possibility of producing high resolution data that can be used for soil moisture estimation. High resolution soil moisture data enables more specific observation of soil moisture than existing soil moisture products from other satellites. It can also be used for studies of wildfire, landslide, and flood. The SAR based soil moisture estimation should be conducted considering vegetation, which affects backscattering signals from the SAR sensor. In this study, a SAR based soil moisture estimation at regions covered with various vegetation types on the middle area of Korea (Cropland, Grassland, Forest) is conducted. The representative backscattering model, Water Cloud Model (WCM) is used for soil moisture estimation over vegetated areas. Radar Vegetation Index (RVI) and in-situ soil moisture data are used as input factors for the model. Total 6 study areas are selected for 3 vegetation types according to land cover classification with 2 sites per each vegetation type. Soil moisture evaluation result shows that the accuracy of each site stands out in the order of grassland, forest, and cropland. Forested area shows correlation coefficient value higher than 0.5 even with the most dense vegetation, while cropland shows correlation coefficient value lower than 0.3. The proper vegetation and soil moisture conditions for SAR based soil moisture estimation are suggested through the results of the study. Future study, which utilizes additional ancillary vegetation data (vegetation height, vegetation type) is thought to be necessary.

Radiometric Cross Calibration of KOMPSAT-3 and Lnadsat-8 for Time-Series Harmonization (KOMPSAT-3와 Landsat-8의 시계열 융합활용을 위한 교차검보정)

  • Ahn, Ho-yong;Na, Sang-il;Park, Chan-won;Hong, Suk-young;So, Kyu-ho;Lee, Kyung-do
    • Korean Journal of Remote Sensing
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    • v.36 no.6_2
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    • pp.1523-1535
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    • 2020
  • In order to produce crop information using remote sensing, we use classification and growth monitoring based on crop phenology. Therefore, time-series satellite images with a short period are required. However, there are limitations to acquiring time-series satellite data, so it is necessary to use fusion with other earth observation satellites. Before fusion of various satellite image data, it is necessary to overcome the inherent difference in radiometric characteristics of satellites. This study performed Korea Multi-Purpose Satellite-3 (KOMPSAT-3) cross calibration with Landsat-8 as the first step for fusion. Top of Atmosphere (TOA) Reflectance was compared by applying Spectral Band Adjustment Factor (SBAF) to each satellite using hyperspectral sensor band aggregation. As a result of cross calibration, KOMPSAT-3 and Landsat-8 satellites showed a difference in reflectance of less than 4% in Blue, Green, and Red bands, and 6% in NIR bands. KOMPSAT-3, without on-board calibrator, idicate lower radiometric stability compared to ladnsat-8. In the future, efforts are needed to produce normalized reflectance data through BRDF (Bidirectional reflectance distribution function) correction and SBAF application for spectral characteristics of agricultural land.

A Study on the View Characteristics of the Pavilion around Gyeongpo Lake (경포호 누정의 조망특성에 관한 연구)

  • Han, Gab-Soo
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.39 no.4
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    • pp.66-76
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    • 2021
  • The purpose of this study was to analyze the transition process of Gyeongpo lake and to analyze the viewing characteristics of each period in the pavilion. The view characteristics at pavilion were analyzed by overlapping classification maps of landscape types by period with the view range map from pavilion. The circumference and area of Gyeongpo lake have been reduced to 15.2km and 3.9km2 in the 1750s, 9.0km and 1.7km2 in the 1933, and now 4.41km and 1.0km2. By period, the largest decrease in the proportion of Gyeongpo lake viewed from Pavilion was Hwanseonjeong, which decreased by 48.0% from the 1750 to 2017. Hwallaejeong, Haeunjeong, and Hohaejeong were found to be impossible to view Gyeongpo lake as some of the adjacent lakes were changed to agricultural land. Pavilion has great significance as a space for traditional culture created in the background of humanities and natural environments. For the succession and development of Pavilion culture, it is necessary to use it as a cultural resource, to continuously manage the building, and to partially restore Gyeongpo lake considering the function of each pavilion.

Analysis of the Cultural Resources of the Gyeokryeolbi Yeoldo at the End of the West Sea in South Korea (서해 끝 무인도 '격렬비열도'의 문화자원 분석)

  • Kim, Jeong-Seob
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.1
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    • pp.143-152
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    • 2021
  • The extremely isolated uninhabited island at the end of the West Sea in South Korea called "The Gyeokryeolbi Yeoldo" has recently begun to be managed by the government under the influence of public opinion demanding the island to be strictly protected. The island was created 70 million years ago by volcanic activities. So it is older than the birth history of Jeju Island, which is estimated to have been born about a million years ago. This study has focused on providing the basis for imagetelling and storytelling of the Gyeokryeolbi Yeoldo, known for its important value by exploring the cultural resources of the island. For the research, the ethnography including in-depth local interview and on-site investigation have been applied for 3 years from February 2018 to December 2020 in Taean, Chungnam Province, where the island is located. To analyze the cultural resources of this island, the resource classification model has been designed and used, which is modified from Valentine (2001) and Chi-ho Nam (2007). As a result, the "tangible cultural resources (TCR)" including various remains found on the island were mainly symbols of cultural bridge in the history of Korea-China exchange, and the spiritual land of life-saving. Also "intangible cultural resources (ICR)" extracted from the island were focused on the images of life protection, safety, bravery, and romance. Based on this study, the core concept of identity to be applied when refurbishing the island with a prominent cultural placeness( "sense of place") can be proposed as "a cultural ecological island centered on the Circular Yellow Sea that ruminates memories of love."

Evaluation of Priorities for Greening of Vacant Houses using Connectivity Modeling (연결성 모델링을 활용한 빈집 녹지화 우선순위 평가)

  • Lee, Hyun-Jung;Kim, Whee-Moon;Kim, Kyeong-Tae;Shin, Ji-Young;Park, Chang-Sug;Park, Hyun-Joo;Song, Won-Kyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.25 no.1
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    • pp.25-38
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    • 2022
  • Urban problems are constantly occurring around the world due to rapid industrialization and population decline. In particular, as the number of vacant houses is gradually increasing as the population decreases, it is necessary to prepare countermeasures. A plan to utilize vacant houses has emerged to restore the natural environment of the urban ecosystem where forest destruction, damage to habitats of wild animals and plants, and disconnection have occurred due to large-scale development. Through connectivity analysis, it is possible to understand the overall ecosystem flow based on the movement of species and predict the effect when vacant houses are converted into green spaces. Therefore, this study analyzed the green area network to confirm the possibility of greening of vacant houses neglected in Jeonju based on circuit theory. Using Circuitscape and Least-cost path, we tried to identify the connectivity of green areas and propose an ecological axis based on the analysis. In order to apply the resistance values required for analysis based on previous studies, the 2020 subdivision land cover data were integrated into the major classification evaluation items. When the eight forests in the target site were analyzed as the standard, the overall connectivity and connectivity between forests in the area were high, so it is judged that the existing green areas can perform various functions, such as species movement and provision of habitats. Based on the results of the connectivity analysis, the importance of vacant houses was calculated and the top 20 vacant houses were identified, and it was confirmed that the higher the ranking, the more positive the degree of landscape connectivity was when converted to green areas. In addition, it was confirmed that the results of analyzing the least-cost path based on the resistance values such as connectivity analysis and the existing conceptual map showed some differences when comparing the ecological axes in the form. As a result of checking the vacant houses corresponding to the relevant axis based on the width standards of the main and sub-green areas, a total of 30 vacant houses were included in the 200m width and 6 vacant houses in the 80m width. It is judged that the conversion of vacant houses to green space can contribute to biodiversity conservation as well as connectivity between habitats of species as it is coupled with improved green space connectivity. In addition, it is expected to help solve the problem of vacant houses in the future by showing the possibility of using vacant houses.

Forest Fire Area Extraction Method Using VIIRS (VIIRS를 활용한 산불 피해 범위 추출 방법 연구)

  • Chae, Hanseong;Ahn, Jaeseong;Choi, Jinmu
    • Korean Journal of Remote Sensing
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    • v.38 no.5_2
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    • pp.669-683
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    • 2022
  • The frequency and damage of forest fires have tended to increase over the past 20 years. In order to effectively respond to forest fires, information on forest fire damage should be well managed. However, information on the extent of forest fire damage is not well managed. This study attempted to present a method that extracting information on the area of forest fire in real time and quasi-real-time using visible infrared imaging radiometer suite (VIIRS) images. VIIRS data observing the Korean Peninsula were obtained and visualized at the time of the East Coast forest fire in March 2022. VIIRS images were classified without supervision using iterative self-organizing data analysis (ISODATA) algorithm. The results were reclassified using the relationship between the burned area and the location of the flame to extract the extent of forest fire. The final results were compared with verification and comparison data. As a result of the comparison, in the case of large forest fires, it was found that classifying and extracting VIIRS images was more accurate than estimating them through forest fire occurrence data. This method can be used to create spatial data for forest fire management. Furthermore, if this research method is automated, it is expected that daily forest fire damage monitoring based on VIIRS will be possible.

Classification of Major Reservoirs Based on Water Quality and Changes in Their Trophic Status in South Korea (수질 특성에 따른 우리나라 주요 호소 분류 및 호소 영양 상태 변동 특성 분석)

  • Dae-Seong Lee;Da-Yeong Lee;Young-Seuk Park
    • Korean Journal of Ecology and Environment
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    • v.55 no.2
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    • pp.156-166
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    • 2022
  • Understanding the characteristics of reservoir water quality is fundamental in reservoir ecosystem management. The water quality of reservoirs is affected by various factors including hydro-morphology of reservoirs, land use/cover, and human activities in their catchments. In this study, we classified 83 major reservoirs in South Korea based on nine physicochemical factors (pH, dissolved oxygen, chemical oxygen demand, total suspended solid, total nitrogen, total phosphorus, total organic carbon, electric conductivity, and chlorophyll-a) measured for five years (2015~2019). Study reservoirs were classified into five main clusters through hierarchical cluster analysis. Each cluster reflected differences in the water quality of reservoirs as well as hydromorphological variables such as elevation, catchment area, full water level, and full storage. In particular, water quality condition was low at a low elevation with large reservoirs representing cluster I. In the comparison of eutrophication status in major reservoirs in South Korea using the Korean trophic state index, in some reservoirs including cluster IV composed of lagoons, the eutrophication was improved compared to 2004~2008. However, eutrophication status has been more impaired in most agricultural reservoirs in clusters I, III, and V than past. Therefore, more attention is needed to improve the water quality of these reservoirs.

Escape Route Prediction and Tracking System using Artificial Intelligence (인공지능을 활용한 도주경로 예측 및 추적 시스템)

  • Yang, Bum-suk;Park, Dea-woo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.05a
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    • pp.225-227
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    • 2022
  • Now In Seoul, about 75,000 CCTVs are installed in 25 district offices. Each ward office in Seoul has built a control center for CCTV control and is building information such as people, vehicle types, license plate recognition and color classification into big data through 24-hour artificial intelligence intelligent image analysis. Seoul Metropolitan Government has signed MOUs with the Ministry of Land, Infrastructure and Transport, the National Police Agency, the Fire Service, the Ministry of Justice, and the military base to enable rapid response to emergency/emergency situations. In other words, we are building a smart city that is safe and can prevent disasters by providing CCTV images of each ward office. In this paper, the CCTV image is designed to extract the characteristics of the vehicle and personnel when an incident occurs through artificial intelligence, and based on this, predict the escape route and enable continuous tracking. It is designed so that the AI automatically selects and displays the CCTV image of the route. It is designed to expand the smart city integration platform by providing image information and extracted information to the adjacent ward office when the escape route of a person or vehicle related to an incident is expected to an area other than the relevant jurisdiction. This paper will contribute as basic data to the development of smart city integrated platform research.

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A Study on the Characteristics of Rural Convention in Geongsang Region - Focused on the Rural Development Projects, Hierarchical Structure and Living Area - (경상지역 농촌협약 특징 - 일반 농산어촌개발사업, 계층구조, 생활권 설정을 중심으로 -)

  • Kim, Sang-Bum;Eom, Seong-Jun;An, Phil-Gyun;Jeong, Myeong-Cheol;Do, Jee-Yoon;Song, Mi-Jeong
    • Journal of the Korean Institute of Rural Architecture
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    • v.24 no.4
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    • pp.67-75
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    • 2022
  • The purpose of this paper is to provide basic data to Si and Gun preparing for rural agreements in the future through consideration and case analysis for rural conventions, such things as living standards, hierarchical analysis methods, and general rural development projects. In the 1970s, sporadic and one-off projects focused on individual projects were repeatedly carried out in rural areas, which were undergoing dramatic changes in population movement, land use, landscape, economic growth and living. The keyword of the government's policy has changed to a way that existing rural development projects are planned and promoted by local governments themselves in conjunction with the issue of autonomy and decentralization. In addition, with the introduction of Rural Convention, the central and local governments are striving to achieve common policy goals. However, due to the lack of understanding of the Rural Convention introduced as a pilot project in 2020, the lack of living areas setting-standards, unclear classification of hierarchical structure, and excessive goal consciousness for general agricultural and fishing village development projects remain, fading the original purpose of the Rural Convention. Therefore, this study analyzed the seven reports of the Gyeongsang region selected in the 2021 Rural Convention to identify the characteristics of living area, hierarchical structure analysis, and detailed projects (rural center revitalization project, basic living base development project) and provided them as basic data. As a result of the study, first, according to the results of the hierarchical structure analysis, the first class was derived from 6 out of 7 Si and Gun. This is judged to be the result of the current rural population, social, and economic problems. Second, according to the results of the division of living areas, it was confirmed that except for one local government in seven cities and counties, the remaining six local governments were divided into three single living areas and three two living areas. This is the result obtained through a comprehensive review by overlapping the results of various analyses such as hierarchical analysis and resident surveys and OD data, and shows a different form from the existing upper or related plans. It is judged that this is the result of including qualitative contents such as residents' opinions along with various analyses when determining the living area. Third, the proportion of the budget for rural center revitalization and basic living base development projects to the total project cost subject to the Rural Convention was 59.6%, which was relatively higher than that of other general agricultural and fishing village development projects. It is judged that it is preferred because the unit project cost is relatively high in Si and Gun, and that quantitative results can be visually shown after the project is terminated.

Enhancement of Geomorphology Generation for the Front Land of Levee Using Aerial Photograph (항공영상을 연계한 하천 제외지의 지형분석 개선 기법)

  • Lee, Geun Sang;Lee, Hyun Seok;Hwang, Eui Ho;Koh, Deuk Koo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3D
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    • pp.407-415
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    • 2008
  • This study presents the methodology to link with aerial photos for advancing the accuracy of topographic survey data that is used to calculate water volume in urban stream. First, GIS spatial interpolation technique as Inverse Distance Weight (IDW) and Kriging was applied to construct the terrain morphology to the sand-bar and grass area using cross-sectional survey data, and also validation point data was used to estimate the accuracy of created topographic data. As the result of comparison, IDW ($d^{-2}_{ij}$, 2nd square number) in Sand-bar area and Kriging Spherical model in grass area showed more efficient results in the construction of topographic data of river boundary. But the differences among interpolation methods are very slight. Image classification method, Minimum Distance Method (MDM) was applied to extract sand-bar and grass area that are located to river boundary efficiently and the elevation value of extracted layers was allocated to the water level point value. Water volume with topographic data from aerial photos shows the advanced accuracy of 13% (in sand-bar) and 12% (in grass) compared to the water volume of original terrain data. Therefore, terrain analysis method in river linking with aerial photos is efficient to the monitoring about sand-bar and grass area that are located in the downstream of Dam in flooding season, and also it can be applied to calculate water volume efficiently.