• Title/Summary/Keyword: surface cover change

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Detection of Heat Change in Urban Center Using Landsat Imagery (Landsat 영상을 이용한 도심의 열변화 탐지)

  • Kang, Joon-Mook;Ka, Myung-Seok;Lee, Sung-Soon;Park, Joon-Kyu
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.2
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    • pp.197-206
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    • 2010
  • Recently, developed countries have continuously been trying to recognize many issues about heat island in urban area and to make up countermeasures for them. This research is designed to extract change of land cover in the area under condition of land development with satellite images and to analyze its effect on the heat change in there. Heat change upon change of land cover in daejeon was analyzed with the four Landsat satellite images taken in April 1985, August 1994, May 2001, and May 2009. In order to measure the temperature on the surface in the city, the land surface temperature was produced with Landsat TM Band 6. Heat change is to detected with it. As a result, The urban area has been increased up to 23.59 percent. On the other hand, the forest area has been decreased up to 27.91%. Due to the urbanization, the temperature on the surface in urban center was higher than surrounding area. In that case, the temperature of urban center area was higher 2.4 to $5.7^{\circ}C$ compared with the forest area.

Land surface change detection in Nagasaki and Kangnung using multi-temporal Landsat data

  • Shaikh, Asif A.;Gotoh, K.;Tachiiri, Kaoru
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.508-510
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    • 2003
  • Land cover change has been recognized as one of the most important factors influencing the occurrence of rainfall-triggered landslides. Satellite remote sensing provides detailed information regarding the spatial distribution and extent of land cover/use changes. This study describes the land cover changes in Nagasaki City, Japan and Kangnung City, South Korea. The former has been suffered from rainfall-triggered disasters for long term and latter was damaged by Typhoon Rusa in 2002. The results obtained from both study areas clearly show that land cover changes have occurred in the last decade as a result of both natural forces and human activities.

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The impact of land use and land cover changes on land surface temperature in the Yangon Urban Area, Myanmar

  • Yee, Khin Mar;Ahn, Hoyong;Shin, Dongyoon;Choi, Chuluong
    • Korean Journal of Remote Sensing
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    • v.32 no.1
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    • pp.39-48
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    • 2016
  • Yangon Mega City is densely populated and most urbanization area of Myanmar. Rapid urbanization is the main causes of Land Use and Land Cover (LULC) change and they impact on Land Surface Temperature (LST). The objectives of this study were to investigate on the LST with respect to LULC of Yangon Mega City. For this research, Landsat satellite images of 1996, 2006 and 2014 of Yangon Area were used. Supervised classification with the region of interest and calculated change detection. Ground check points used 348 points for accuracy assessment. The overall accuracy indicated 89.94 percent. The result of this paper, the vegetation area decreased from $1061.08sq\;km^2$ (24.5%) in 1996 to $483.53sq\;km^2$ (11.2%) in 2014 and built up area clearly increased from $485.33sq\;km^2$ (11.2%) in 1996 to $1435.72sq\;km^2$ (33.1%) in 2014. Although the land surface temperature was higher in built up area and bare land, lower value in cultivated land, vegetation and water area. The results of the image processing pointed out that land surface temperature increased from $23^{\circ}C$, $26^{\circ}C$ and $27^{\circ}C$ to $36^{\circ}C$, $42^{\circ}C$ and $43.3^{\circ}C$ for three periods. The findings of this paper revealed a notable changes of land use and land cover and land surface temperature for the future heat management of sustainable urban planning for Yangon Mega city. The relationship of regression experienced between LULC and LST can be found gradually stronger from 0.8323 in 1996, 0.8929 in 2006 and 0.9424 in 2014 respectively.

NDVI RESPONSES TO THE FOREST CANOPY AND FLOOR IN EASTERN SIBERIA

  • Suzuki, Rikie;Kobayashi, Hideki;Delbart, Nicolas;Hiyama, Tetsuya;Asanuma, Jun
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.325-328
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    • 2007
  • We discuss the Normalized Difference Vegetation Index (NDVI) of the forest canopy and floor separately based on airborne spectral reflectance measurements and simultaneous airborne land surface images acquired around Yakutsk, Siberia in 2000. The aerial land surface images were visually classified into four forest types: no-green canopy and snow floor (Type-1), green canopy and snow floor (Type-2), no-green canopy and no-snow floor (Type-3), and green canopy and no-snow floor (Type-4). The mean NDVI was calculated for these four types. Although Type-2 had green canopy, the NDVI was rather small (0.17) because of high reflection from the snow cover on the floor. Type-3, which had no green canopy, indicated considerably large NDVI (0.45) due to the greenness of the floor. Type-4 had the largest NDVI (0.75) because of the greenness of both the canopy and floor. These results reveal that the NDVI depends considerably on forest floor greenness and snow cover in addition to canopy greenness.

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Structural Dynamics Modification Using Surface Grooving Technique : Modified Algorithm and Result of Fine HDD Cover Model (개선된 알고리즘을 이용한 그루브를 통한 표면형상변형 동특성 변경법)

  • Park, Mi-You;Park, Young-Jin;Park, Youn-Sik
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.834-837
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    • 2005
  • Structural Dynamics Modification (SDM) is a very effective technique to improve structure's dynamic characteristics by adding or removing auxiliary structures, changing material properties and shape of structure. Among those of SDM technique, the method to change shape of structure has been mostly relied on engineer's experience and trial-and-error process which are very time consuming. In order to develop a systematic method to change structure shape, surface grooving technique is studied and successfully applied to HDD cover model. At first, to check the effect of mesh size, surface grooving technique was tested to the fine HDD cover FEmodel. And fur the more efficient method, the algorithm is modified. Removing the low-valued modal strain energy element among the target domain, computational effort can be greatly reduced and the result of simulation is similar with the other simulation result.

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Guidelines of 2D Pattern Development Process for 3D Fitted Cover of Character Toys (캐릭터 인형용 밀착커버 패턴개발 프로세스의 가이드라인)

  • Lee, Heeran
    • Fashion & Textile Research Journal
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    • v.19 no.5
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    • pp.635-645
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    • 2017
  • The industry of character toys is increasing and new characters are constantly being developed. However, the development of 2D cover patterns for toys is time-consuming due to frequent pattern modifications made through trial and error. Studies are now underway to obtain 2D clothing patterns from 3D body data, however, little research has been done on 2D pattern of character toys. This study suggests efficient guidelines to develop 2D cover patterns with a reasonable accuracy and processing time. Two 3D models of a dog and rabbit were used to develop 2D cover patterns. Independent variables of this study are set as 3 levels of triangle area (small, medium, and large) that influence the efficacy of 3D and 2D pattern development. The determination of the appropriate triangular area was based on the area and shape change of the 2D pattern. A medium or large triangle area was shown to be suitable for a character dog with a smooth curved surface. However, the appropriate triangle area was small if the characteristics of the curved surface are complicated as in the case of rabbit. The head of a dog (a double-curved surface) and the curved forepaw of a rabbit (a triangular area) should be small when the characteristics of the curved surface (such as the hind leg of a rabbit having a large convex surface and a small surface area) are complicated. Grouping by 3D surface characteristics could be a suitable guideline for the triangle area selection.

Long-term Sediment Discharge Analysis in Yongdam Dam Watershed due to Climate Change

  • Felix, Micah Lourdes;Kim, Joocheol;Choi, Mikyoung;Jung, Kwansue
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.327-327
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    • 2020
  • Increase in Earth's surface temperature, higher rainfall intensity rate, and rapid changes in land cover are just some of the most evident effects of climate change. Flooding, and river sedimentation are two inevitable natural processes in our environment, and both issues poses great risks in the dam industry when not addressed properly. River sedimentation is a significant issue that causes reservoir deposition, and thus causes the dam to gradually lose its ability to store water. In this study, the long-term effects of climate change on the sediment discharge in Yongdam Dam watershed is analyzed through the utilization of SWAT, a semi-distributed watershed model. Based from the results of this study, an abrupt increase on the annual sediment inflow trend in Yongdam Dam watershed was observed; which may suggests that due to the effects of climate change, higher rainfall intensity, land use and land cover changes, the sedimentation rate also increased. An efficient sedimentation management should consider the increasing trend in sedimentation rate due to the effects of climate change.

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Analysis of the Surface Urban Heat Island Changes according to Urbanization in Sejong City Using Landsat Imagery (Landsat영상을 이용한 토지피복 변화에 따른 행정중심복합도시의 표면 열섬현상 변화분석)

  • Lee, Kyungil;Lim, Chul-Hee
    • Korean Journal of Remote Sensing
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    • v.38 no.3
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    • pp.225-236
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    • 2022
  • Urbanization due to population growth and regional development can cause various environmental problems, such as the urban heat island phenomenon. A planned city is considered an appropriate study site to analyze changes in urban climate caused by rapid urbanization in a short-term period. In this study, changes in land cover and surface heat island phenomenon were analyzed according to the development plan in Sejong City from 2013 to 2020 using Landsat-8 Operational Land Imager/Thermal Infrared Sensor (OLI/TIRS) satellite imagery. The surface temperature was calculated in consideration of the thermal infrared band value provided by the satellite image and the emissivity, and based on this the surface heat island effect intensity and Urban Thermal Field Variance Index (UTFVI) change analysis were performed. The level-2 land cover map provided by the Ministry of Environment was used to confirm the change in land cover as the development progressed and the difference in the surface heat island intensity by each land cover. As a result of the analysis, it was confirmed that the urbanized area increased by 15% and the vegetation decreased by more than 28%. Expansion and intensification of the heat island phenomenon due to urban development were observed, and it was confirmed that the ecological level of the area where the heat island phenomenon occurred was very low. Therefore, It can suggest the need for a policy to improve the residential environment according to the quantitative change of the thermal environment due to rapid urbanization.

Analysis of the Surface Urban Heat Island Changes according to NewTowns Development and Correlation with Urban Morphology (신도시 개발에 따른 표면 열섬현상 변화분석 및 도시 형태와의 상관관계)

  • Kyungil Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.5_3
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    • pp.921-932
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    • 2023
  • Land cover change due to urban population concentration and urban expansion can cause various environmental problems such as urban heat islands. In particular, New towns are considered an appropriate study site to analyze changes in urban climate due to rapid urbanization in a short period. This study used Landsat satellite imagery to compare and analyze the land cover changes before and after the development of two new towns with different plans, and the resulting changes in surface urban heat island (SUHI) phenomena. Correlation analysis was also conducted between urban structural features that may affect the SUHI intensity. The results of the analysis confirm the rapid change in land cover as new town development progresses and the direct intensification of the SUHI phenomenon. This study confirms the differences in SUHI caused by different urban plans and suggests the need for three-dimensional urban planning to improve the thermal environment.

The Trend Analysis of Vegetation Change Applied to Unsupervised Classification Over East Asia: Using the NDVI 10-day data in 1999~2010 (무감독분류 기법을 이용한 동아시아지역의 식생변화 경향분석: 1999~2010 NDVI 10-day 자료를 바탕으로)

  • Kim, Sang-Il;Han, Kyung-Soo;Pi, Kyoung-Jin
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.4
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    • pp.153-159
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    • 2011
  • Vegetative land cover is an important variable many Earth system process, general circulation and carbon exchange model requires vegetative cover as boundary layer necessary to run model. The purpose of this study is to detect and to understand land surface change. To monitor changes of East Asia vegetation, we used NDVI 10-day MVC data derived from SPOT VEGETATION during 12 years from 1999 to 2010. Finally, according to the land cover of classified class, we performed analysis for dynamic zone(positive change zone and negative change zone), static zone in 1999, 2010. Therefore, land covers corresponding to each class have appeared change by 2010. Land cover change was confirmed by analyzing data during 12 years which appeared vegetation change of surrounding the actual desert area to east.