• Title/Summary/Keyword: Landsat/TM

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Satellite Remote Sensing for Forest Surveys and Management (산림조사(山林調査) 및 경영(經營)을 위(爲한) 위성원격탐사(衛星遠隔探査))

  • Choung, Song Hak
    • Journal of Korean Society of Forest Science
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    • v.83 no.1
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    • pp.75-87
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    • 1994
  • The states of development of remote sensing, GIS and forest management technology are such that new directions in forest surveys and management are possible. The technologies can not be considered separately. With the increasing power and decreasing cost of computer processing and the development of inexpensive mass storage media, digital remote sensing applications are becoming more practical. Powerful microcomputer-based image analysis systems and GIS are important advancements. As well, it is only a matter of time before the integration of remote sensing image analysis systems and GIS becomes transparent to the users. Implementation of operational applications by both centralized agencies and local units is, therefore, becoming practical. This paper discussed the state of remote sensing technology and its application to forest surveys and management. The relative advantages and disadvantages of readily available remote sensing products for regional biodiversity assessment were summarized. Discussion is limited to the sources of up-to-date imagery suitable for regional land use/cover mapping, specifically : LANDSAT MSS and TM, and SPOT.

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A Study of Assessment Techniques of Water Quality Using Remotely Sensed Data (원격탐사 자료에 의한 수질평가기법에 관한 연구)

  • 장동호;지광훈;이현영
    • Journal of the Korean Geographical Society
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    • v.35 no.1
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    • pp.3-15
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    • 2000
  • 산업화와 더불어 심각해지고 있는 수질오염 문제를 해결하기 위해서는 여러 가지 수질관리 방안이 요구된다. 수질오염이 과거에는 국지적이었으나 점차 광범한 지역으로 확장됨에 다라 지속적인 수질 모니터링에 어려움이 따른다. 본 연구에서는 위성영상을 사용한 원격탐사 기법으로 수역의 수질환경 인자를 추출하고자 한다. 사용된 영상은 Landasat TM이며, 연구지역은 한강하류 지역이다. 수질분석 인자는 클로로필-a, 부유물질, 투명도 등을 선정하였으며, 수면분광반사율의 특징 및 수질인자별 처리기법을 개발하는데 목적을 두었다. 분광특성 분석결과를 요약하면, 첫 번째 스펙트럼 반사율 분석결과 클로로필-a의 농도는 0.4~0.5$\mu\textrm{m}$ 파장대역에서 낮은 반사치 경향을 보이며, 녹색파장대인 0.57$\mu\textrm{m}$ 부근에서 반사율이 높아진다. 두 번째 부유물질의 반사도는 농도가 증가할수록 0.8$\mu\textrm{m}$ 부근에서 상대적으로 낮은 반사율이 나타난다. 마지막으로 투명도가 낮은 수면은 0.55$\mu\textrm{m}$에서 높은 반사율 경향을 보인다. Landsat TM영상을 이용하여 주성분분석 및 비연산처리를 실시하여 수질분석을 시도한 결과를 보면 클로로필-a와 투명도는 제1주성분 영상 및 제2주성분 영상에서 현장 실측자료와 유사한 결과를 얻을 수 있었으며, 부유물질은 밴드 2와 밴드 4의 비연산처리를 통하여 분포도를 작성할 수 있었다. 이상의 결과들은 계절적 및 시간적 변화에 따라 파장대역이 달라질 수 있다. 그러므로 위성자료를 이용하여 보다 정확한 수질환경 인자를 추출하기 위해서는 현장실측 및 수역의 분광반사 특성을 지속적으로 조사하여야 한다.때문으로 경주 산사태와 포함-구릉포간 국도면의 산사태가 이 종류의 산사태에 속한다.열 인식의 신뢰도를 향상시킬수 있는 방법을 제안하였다.작성하여 최신 의료영상 처리 기법을 쉽게 임상에 적용하고 실험할 수 있는 장점이 있다. 지대에서 가능하였고, 파종기는 중생종보다 이르게 나타났다. 등숙만한출수기 기준의 안전작기는 조생종과 중생종은 태백고냉지대와 태백준고냉지대, 소백산간지대 일부지역을 제외한 다른 지역에서 설정되었고, 중만생종은 태백고냉지대, 태백준고냉지대, 동해안북부지대, 소백산간지대, 노령소백산간지대의 일부 지역은 벼 담수직파가 불가능하게 판단되었다. information on the regular basis of time and provide it when the users query over the Web-database gateway. The other approach is a shopping agent mechanism, which stores information on "how to shop" and the shopping agent collects the information of product items just after users query about the product and provide the information in real time or notify them by alerting service. Thirty nine shopping information services are compared and classified in this paper and they are extracted from "Naver" and "Yahoo! Korea". The final result shows that most services are just a

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Methodology to Apply Low Spatial Resolution Optical Satellite Images for Large-scale Flood Mapping (대규모 홍수 매핑을 위한 저해상도 광학위성영상의 활용 방법)

  • Piao, Yanyan;Lee, Hwa-Seon;Kim, Kyung-Tak;Lee, Kyu-Sung
    • Korean Journal of Remote Sensing
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    • v.34 no.5
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    • pp.787-799
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    • 2018
  • Accurate and effective mapping is critical step to monitor the spatial distribution and change of flood inundated area in large scale flood event. In this study, we try to suggest methods to use low spatial resolution satellite optical imagery for flood mapping, which has high temporal resolution to cover wide geographical area several times per a day. We selected the Sebou watershed flood in Morocco that was occurred in early 2010, in which several hundred $km^2$ area of the Gharb lowland plain was inundated. MODIS daily surface reflectance product was used to detect the flooded area. The study area showed several distinct spectral patterns within the flooded area, which included pure turbid water and turbid water with vegetation. The flooded area was extracted by thresholding on selected band reflectance and water-related spectral indices. Accuracy of these flooding detection methods were assessed by the reference map obtained from Landsat-5 TM image and qualitative interpretation of the flood map derived. Over 90% of accuracies were obtained for three methods except for the NDWI threshold. Two spectral bands of SWIR and red were essential to detect the flooded area and the simple thresholding on these bands was effective to detect the flooded area. NIR band did not play important role to detect the flooded area while it was useful to separate the water-vegetation mixed flooded classes from the purely water surface.

Analysis on Effect Area of Subway Station Using GIS & Multi-temporal Satellite Images (GIS와 다시기 위성영상을 이용한 전철역세권의 분석)

  • Park, Jae-Kook;Kim, Dong-Moon;Yang, In-Tae
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.25 no.2
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    • pp.107-115
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    • 2007
  • Among public transportation facilities within urban area, electric railway (subway) has been a regionally based facility that has played an important role in improving the foundation of territory development and arrangement of living foundation and living environment while supplementing the regional road network. In this regard, the subway stations should be allocated in the right place to ensure mobility, convenience and economic feasibility, some of transportation characteristics of road network combined with the subway. However, it would be very hard to evaluate quantitatively the effects of public transportation facilities such as subway in metropolitan cities on regional development and change in land use and to suggest the data that would be utilized in future city planning corresponding to their results. Therefore, this study evaluated the change in land use by the conditions of location of subway stations quantitatively; then, it evaluated and analyzed the change in land use for the internal and external parts of the surrounding areas of subway stations through the GIS spatial analysis and classification of landsat TM satellite image for utilizing it as reference material for the new establishment of subway stations in the future.

A Study on distribution and change of NDVI with Land-Cover change in City of Sungnam (토지피복 변화에 따른 식생지수(NDVI)분포 및 변화에 관한 연구: 성남시를 중심으로)

  • 성효현;박옥준
    • Spatial Information Research
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    • v.8 no.2
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    • pp.275-288
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    • 2000
  • The purpose of this study is to analyze relationship between the NDVI change pattern and landcover change pattern in the City of Sungnam during 1985 and 1996. The results of this study are as follows; (1) NDVI of the level 6 and 7 is decreased and the level 5 is increased in the area where Forst area changed to the other land cover during 1985 and 1996. (2) In the area where Agricultural-Pasture changed to forest, NDVI level became higher certainly during that time. But in the area where there has been changed from Agricultural-Pasture to Urban or built-up, Agricultural-Pasture to Barren land, the level of NDVI is decreased. (3) In the Urban or built-up to other land, or built-up the level of NDVI is increased. (4) In the area where Barren land changed to other land cover, the level of NDVI is increased.

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Classification of Degraded Peat Swamp Forest for Restoration Planning at Landscape Level Using Remote Sensing Technique

  • Hamzah, Khali Aziz;Idris, Azahan Shah;Parlan, Ismail
    • Journal of Forest and Environmental Science
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    • v.29 no.1
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    • pp.49-57
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    • 2013
  • Malaysia possesses about 1.56 million ha of Peat Swamp Forest (PSF). The PSF safeguard enormous biological diversity, while providing crucial benefits for the sustainable development of human communities. Numbers of threatened plant species are associated with the PSF, including the commercially important Gonystylus bancanus timber. To prevent significant losses of biodiversity, it is important to manage the PSF for both biological conservation and sustainable use. Equally important is to restore all degraded PSF in an attempt to ensure the PSF ecosystem is suitable for the vegetation to grow and rehabilitate back to the normal condition. Prior to plan any forest restoration program, there is a need to properly map the degraded PSF in order to estimate the forest conditions and determine the vegetations status. Most of the time this need to be done at a landscape level and requires a technology that can provide accurate, timely and reliable information for the planner to make decision. This paper describes a study using geospatial technology in combination with ground survey to classify the degraded PSF in South East Pahang Peat Swamp Forest (SEPPSF), Malaysia, into different degree of vegetation classes. With map accuracy of about 83%, the technique proved to be useful in delineating the different degree of PSF degradation from which the information can be used to properly plan forest restoration program in the area. The final output which is in the form of map can be used in developing a Restoration Master Plan for the degraded PSF areas.

Spatial Relationship of Suburb, Road and River in respect to Forest Canopy Density Change Using GIS and RS

  • Pantal, Menaka;Kim, Kye-Hyun
    • 한국공간정보시스템학회:학술대회논문집
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    • 2005.11a
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    • pp.257-270
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    • 2005
  • Many studies states that improperly uprising of infrastructure may cause leading the forest degradation and canopy reduction in many tropical forest of Asian countries. Other studies revealed that habitat destruction and fragmentation, edge effects, exotic species invasions, pollution are provoked by roads. Similarly, environmental effects of road construction in forests are problematic. Similarly, many researches have been indicated that roads have a far greater impact on forests than simply allowing greater access for human use. Moreover, people using river as means of transportation hence illegal logging and felling cause canopy depletion in many countries. Therefore, it is important to comprehend the study about spatial relation of road, river and suburb followed by temporal change of forest canopy phenomena. This study also tried to examine the effect of road, river and suburb in forest canopy density change of Terai forest of Nepal from you 1988 to 2001. So, Landsat TM88, 92 and 001 and FCD (Forest Canopy Density) mapper were used to perform the spatial .elation of canopy density change. ILWIS (Integrated Land and Water Information System) which is GIS software and compatible with remote sensing data was used to execute analysis and visualize the results. Study found that influence of distance to suburb and river had statistically significance influenced in canopy change. Though road also influenced canopy density much but didn't show a statistical relation. It can be concluded from this research that understanding of spatial relation of factors respect with canopy change is quite complex phenomena unless detail analysis of surrounding environment. Hence, it is better to carry out comprehensive analysis with other additional factors such as biophysical, anthropogenic, social, and institutional factors for proper approach of their effect on canopy change.

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A Study on the Change Detection of Multi-temporal Data - A Case Study on the Urban Fringe in Daegu Metropolitan City - (대도시 주변지역의 토지이용변화 - 대구광역시를 중심으로 -)

  • 박인환;장갑수
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.1
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    • pp.1-10
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    • 2002
  • The purpose of this article is to examine land use change in the fringe area of a metropolitan city through multi-temporal data analysis. Change detection has been regarded as one of the most important applications for utilization of remotely sensed imageries. Conventionally, two images were used for change detection, and Arithmetic calculators were generally used on the process. Meanwhile, multi-temporal change detection for a large number of images has been carried out. In this paper, a digital land-use map and three Landsat TM data were utilized for the multi-temporal change detection Each urban area map was extracted as a base map on the process of multi-temporal change detection. Each urban area map was converted to bit image by using boolean logic. Various urban change types could be obtained by stacking the urban area maps derived from the multi-temporal data using Geographic Information System(GIS). Urban change type map was created by using the process of piling up the bit images. Then the urban change type map was compared with each land cover map for the change detection. Dalseo-gu of Daegu city and Hwawon-eup of Dalsung-gun, the fringe area of Daegu Metropolitan city, were selected for the test area of this multi-temporal change detection method. The districts are adjacent to each other. Dalseo-gu has been developed for 30 yeais and so a large area of paddy land has been changed into a built-up area. Hwawon-eup, near by Dalseo-gu, has been influenced by the urbanization of Dalseo-gu. From 1972 to 1999, 3,507.9ha of agricultural area has been changed into other land uses, while 72.7ha of forest area has been altered. This agricultural area was designated as a 'Semi-agricultural area'by the National landuse Management Law. And it was easy for the preserved area to be changed into a built-up area once it would be included as urban area. Finally, the method of treatment and management of the preserved area needs to be changed to prevent the destruction of paddy land by urban sprawl on the urban fringe.

A Study on Changes in Local Meteorological Fields due to a Change in Land Use in the Lake Shihwa Region Using Synthetic Land Cover Data and High-Resolution Mesoscale Model (합성토지피복자료와 고해상도 중규모 모형을 이용한 시화호 지역의 토지이용 변화에 따른 주변 기상장 변화 연구)

  • Park, Seon Ki;Kim, Jee-Hee
    • Atmosphere
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    • v.21 no.4
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    • pp.405-414
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    • 2011
  • In this study, the influence of a change in land use on the local weather fields is investigated around the Lake Shihwa area using synthetic land cover data and a high-resolution mesoscale model - the Weather Research and Forecasting (WRF). The default land cover data generally used in the WRF is based on the land use category of the United States Geological Survey (USGS), which erroneously presents most land areas of the Korean Peninsula as savannas. To revise such a fault, a multi-temporal land cover data, provided by the Ministry of Environment of Korea, was employed to generate a land cover map of 2005 subject to the land use in Korea at that time. A new land cover map of 1989, before the construction of the Lake Shihwa, was made based on the 2005 map and the Landsat 4-5 TM satellite images of two years. Over the areas where the land use had been changed (e.g., from sea to wetlands, towns, etc.) due to the Lake Shihwa development project, the skin temperature decreased by up to $8^{\circ}C$ in the winter case while increased by as much as $14^{\circ}C$ in the summer case. Changes in the water vapor mixing ratio were mostly affected by advection and topography in both seasons, with considerable increase in the summer case due to continuous sea breeze. Local decrease in water vapor occurred over high land use change areas and/or over downstream of such areas where alteration in wind fields were induced by changes in skin temperature and surface roughness at the areas of land use changes. The albedo increased by about 0.1% in the regions where sea was converted into wetland. In the regions where urban areas were developed, such as Songdo New Town and Incheon International Airport, the albedo increased by up to 0.16%.

Assessment of the Ochang Plain NDVI using Improved Resolution Method from MODIS Images (MODIS영상의 고해상도화 수법을 이용한 오창평야 NDVI의 평가)

  • Park, Jong-Hwa;La, Sang-Il
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.9 no.6
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    • pp.1-12
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    • 2006
  • Remote sensing cannot provide a direct measurement of vegetation index (VI) but it can provide a reasonably good estimate of vegetation index, defined as the ratio of satellite bands. The monitoring of vegetation in nearby urban regions is made difficult by the low spatial resolution and temporal resolution image captures. In this study, enhancing spatial resolution method is adapted as to improve a low spatial resolution. Recent studies have successfully estimated normalized difference vegetation index (NDVI) using improved resolution method such as from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard EOS Terra satellite. Image enhancing spatial resolution is an important tool in remote sensing, as many Earth observation satellites provide both high-resolution and low-resolution multi-spectral images. Examples of enhancement of a MODIS multi-spectral image and a MODIS NDVI image of Cheongju using a Landsat TM high-resolution multi-spectral image are presented. The results are compared with that of the IHS technique is presented for enhancing spatial resolution of multi-spectral bands using a higher resolution data set. To provide a continuous monitoring capability for NDVI, in situ measurements of NDVI from paddy field was carried out in 2004 for comparison with remotely sensed MODIS data. We compare and discuss NDVI estimates from MODIS sensors and in-situ spectroradiometer data over Ochang plain region. These results indicate that the MODIS NDVI is underestimated by approximately 50%.