• Title/Summary/Keyword: land cover data

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Analysis of Land Cover Change Around Desert Areas of East Asia (식생 자료를 이용한 동아시아 사막 주변의 토지피복 변화 분석)

  • Ryu, Jae-Hyun;Han, Kyung-Soo;Pi, Kyoung-Jin;Lee, Min-Ji
    • Korean Journal of Remote Sensing
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    • v.29 no.1
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    • pp.105-114
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    • 2013
  • Desertification of the East Asia area induced by human's indiscriminate activities and natural causes has gradually expanded and demanded scientific research for monitoring and predicting land cover condition. Therefore, this research classified land types which were compared to MODIS land cover and analyzed the extent of barren zone effecting Korea through yellow dust using S10-DAY MVC NDVI from SPOT between 1999 and 2011. This study used unsupervised classification after processing NDVI Correction and Water Mask for eliminating noise values included in the data for enhancement of classification accuracy. The results of analysis are that there are active variations near the borders of desert, especially the Mongolian steppe and the Gobi Desert in central Asia. In addition, the extent of entire desert has been decreased in the middle of the last decade, although desertification is in going on in East Asia.

Application of High Resolution Land Use Data on the Possibility to Mitigate Urban Thermal Environment (고해상도 지표자료를 이용한 도시 열환경 완화효과 가능성에 관한 연구)

  • Lee, Kwi-Ok;Lee, Hyun-Ju;Lee, Hwa-Woon
    • Journal of Environmental Science International
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    • v.18 no.4
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    • pp.423-434
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    • 2009
  • In recent years, the urban thermal environment has become worse, such as days on which the temperature goes above $30^{\circ}C$, sultry nights and heat stroke increase, due to the changes in terrestrial cover such as concrete and asphalt and increased anthropogenic heat emission accompanied by artificial structure. The land use type is an important determinant to near-surface air temperature. Due to these reasons we need to understand and improve the urban thermal environment. In this study, the fifth-generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model(MMS) was applied to the metropolitan of Daegu area in order to investigate the influence of land cover changes and urban modifications increase of Albedo to the surface energy budget on the simulated near-surface air temperature and wind speed. The single urban category in existing 24-category U.S. Geological survey land cover classification used in MM5 was divided into 6 classes to account for heterogeneity of urban land cover. As a result of the numerical simulation intended for the metropolitan of Daegu assumed the increase of Albedo of roofs, buildings, or roads, the increase of Albedo (Cool scenario)can make decrease radiation effect of surface, so that it caused drops in ambient air temperature from 0.2 to 0.3 on the average during the daylight hours and smaller (or near-zero) decrease during the night. The Sensible heat flux and Wind velocity is decreased. Modeling studies suggest that increased surface albedo in urban area can reduce surface and air temperatures near the ground and affect related meteorological parameters such as winds, surface air temperature and sensible heat flux.

Detection of Land Cover Change Using Landsat Image Data in Desert Area (Landsat 영상자료를 이용한 사막지역의 토지피복 변화 분석)

  • M, Erdenechimeg;Choi, Byoung-Gil;Na, Young-Woo;Kim, Tae-Hoon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.4
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    • pp.471-476
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    • 2010
  • This study aimed at monitoring, mapping, and assessing the land degradation in the desert area. In this research, the Landsat TM and ETM+ imageries to assess the extent of land degradation for study area during the period from 1991 to 2007. Were used to study supervized, unsupervized classfication and NDVI land cover changes in the desert area in Mongolia. The classified map consists of five classes of water, vegetation, slight desertification, middle desertification and sever desertification. It shows that for determination classfication methods and NDVI, desertification map of the study area are prepared. The result showed accounting for a clear deterioration in vegetative cover, an increase of sever desertification and a decrease in middle desertification and slight desertification respectively of the total study area.

A Study on the Land-Use Changes on the Balan Water sheds Using the Multi-temperature Landsat TM Images (다시기 Landsat TM 영상을 이용한 소유역의 토지이용변화분석)

  • 강문성;박승우
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1999.10c
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    • pp.473-478
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    • 1999
  • The purpose of the study were to detect and evaluate the land use and changes on the Balan Watersheds, located southwest of Suwon, using the Thematic Mapper(TM) data. Three sests of TM taken in 1985 , 1993 and 1996 were used and the changes in the land use analyzed and compared. The suupervised and unsuperivised classification methods were adoppted to classify five land-cover categories ; Paddy , upland , forest , residential , and water. Future ladn use patterns were simulated using a Markow chain method, and the change ratios presented.

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A Study on the Land Use Classification of Seoul, Tajeon, Incheon Areas by Remote Sensing Technique (원격탐사 기법에 의한 서울, 대전, 인천지역 토지이용 분류연구)

  • 연상호
    • Korean Journal of Remote Sensing
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    • v.2 no.2
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    • pp.69-77
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    • 1986
  • This study was emphasized on the land use classification by Remote Sensing Technique. Land cover maps about the major urbans, Seoul, Tajeon regions, its of each classified classes were extracted by use of Landsat MSS Data and Digital Image Processing System. From the results of this study, it was proved that land use classification by Remote Sensing technique could be used to obtain fully fruitful Results.

Analyzing Difference of Urban Forest Edge Vegetation Condition by Land Cover Types Using Spatio-temporal Data Fusion Method (시공간 위성영상 융합기법을 활용한 도시 산림 임연부 인접 토지피복 유형별 식생 활력도 차이 분석)

  • Sung, Woong Gi;Lee, Dong Kun;Jin, Yihua
    • Journal of Environmental Impact Assessment
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    • v.27 no.3
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    • pp.279-290
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    • 2018
  • The importance of monitoring and assessing the status of urban forests in the aspect of urban forest management is emerging as urban forest edges increase due to urbanization and human impacts. The purpose of this study was to investigate the status of vegetation condition of urban forest edge that is affected by different land cover types using $NDVI_{max}$ images derived from FSDAF (Flexible Spatio-temporal DAta Fusion). Among 4 land cover types,roads had the greatest effect on the forest edge, especially up to 30m, and it was found to affect up to 90m in Seoul urban forest. It was also found that $NDVI_{max}$ increased with distance away from the forest edge. The results of this study are expected to be useful for assessing the effects of land cover types and land cover change on forest edges in terms of urban forest monitoring and urban forest management.

Locally adaptive intelligent interpolation for population distribution modeling using pre-classified land cover data and geographically weighted regression (지표피복 데이터와 지리가중회귀모형을 이용한 인구분포 추정에 관한 연구)

  • Kim, Hwahwan
    • Journal of the Korean association of regional geographers
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    • v.22 no.1
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    • pp.251-266
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    • 2016
  • Intelligent interpolation methods such as dasymetric mapping are considered to be the best way to disaggregate zone-based population data by observing and utilizing the internal variation within each source zone. This research reviews the advantages and problems of the dasymetric mapping method, and presents a geographically weighted regression (GWR) based method to take into consideration the spatial heterogeneity of population density - land cover relationship. The locally adaptive intelligent interpolation method is able to make use of readily available ancillary information in the public domain without the need for additional data processing. In the case study, we use the preclassified National Land Cover Dataset 2011 to test the performance of the proposed method (i.e. the GWR-based multi-class dasymetric method) compared to four other popular population estimation methods (i.e. areal weighting interpolation, pycnophylactic interpolation, binary dasymetric method, and globally fitted ordinary least squares (OLS) based multi-class dasymetric method). The GWR-based multi-class dasymetric method outperforms all other methods. It is attributed to the fact that spatial heterogeneity is accounted for in the process of determining density parameters for land cover classes.

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A Study on Terrain Construction of Unmanned Aerial Vehicle Simulator Based on Spatial Information (공간정보 기반의 무인비행체 시뮬레이터 지형 구축에 관한 연구)

  • Park, Sang Hyun;Hong, Gi Ho;Won, Jin Hee;Heo, Yong Seok
    • Journal of Korea Multimedia Society
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    • v.22 no.9
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    • pp.1122-1131
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    • 2019
  • This paper covers research on terrain construction for unmanned aerial vehicle simulators using spatial information that was distributed by public institutions. Aerial photography, DEM, vector maps and 3D model data were used in order to create a realistic terrain simulator. A data converting method was suggested while researching, so it was generated to automatically arrange and build city models (vWorld provided) and classification methods so that realistic images could be generated by 3D objects. For example: rivers, forests, roads, fields and so on, were arranged by aerial photographs, vector map (land cover map) and terrain construction based on the tile map used by DEM. In order to verify the terrain data of unmanned aircraft simulators produced by the proposed method, the location accuracy was verified by mounting onto Unreal Engine and checked location accuracy.

Feature Extraction and Fusion for land-Cover Discrimination with Multi-Temporal SAR Data (다중 시기 SAR 자료를 이용한 토지 피복 구분을 위한 특징 추출과 융합)

  • Park No-Wook;Lee Hoonyol;Chi Kwang-Hoon
    • Korean Journal of Remote Sensing
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    • v.21 no.2
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    • pp.145-162
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    • 2005
  • To improve the accuracy of land-cover discrimination in SAB data classification, this paper presents a methodology that includes feature extraction and fusion steps with multi-temporal SAR data. Three features including average backscattering coefficient, temporal variability and coherence are extracted from multi-temporal SAR data by considering the temporal behaviors of backscattering characteristics of SAR sensors. Dempster-Shafer theory of evidence(D-S theory) and fuzzy logic are applied to effectively integrate those features. Especially, a feature-driven heuristic approach to mass function assignment in D-S theory is applied and various fuzzy combination operators are tested in fuzzy logic fusion. As experimental results on a multi-temporal Radarsat-1 data set, the features considered in this paper could provide complementary information and thus effectively discriminated water, paddy and urban areas. However, it was difficult to discriminate forest and dry fields. From an information fusion methodological point of view, the D-S theory and fuzzy combination operators except the fuzzy Max and Algebraic Sum operators showed similar land-cover accuracy statistics.