• Title/Summary/Keyword: Land cover ratio

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Sensitivity Analysis of Near Surface Air Temperature to Land Cover Change and Urban Parameterization Scheme Using Unified Model (통합모델을 이용한 토지피복변화와 도시 모수화 방안에 따른 지상 기온 모의성능 민감도 분석)

  • Hong, Seon-Ok;Byon, Jae-Young;Park, HyangSuk;Lee, Young-Gon;Kim, Baek-Jo;Ha, Jong-Chul
    • Atmosphere
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    • v.28 no.4
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    • pp.427-441
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    • 2018
  • This study examines the impact of the urban parameterization scheme and the land cover change on simulated near surface temperature using Unified Model (UM) over the Seoul metropolitan area. We perform four simulations by varying the land cover and the urban parameterization scheme, and then compare the model results with 46 AWS observation data from 2 to 9 August 2016. Four simulations were performed with different combination of two urban parameterization schemes and two land cover data. Two schemes are Best scheme and MORUSES (Met Office Reading Urban Surface Exchange Scheme) and two land cover data are IGBP (International Geosphere and Biosphere Programme) and EGIS (Environmental Geographic information service) land cover data. When land use data change from IGBP to EGIS, urban ratio over the study area increased by 15.9%. The results of the study showed that the higher change in urban fraction between IGBP and EGIS, the higher the improvement in temperature performance, and the higher the urban fraction, the higher the effect of improving temperature performance of the urban parameterization scheme. 1.5-m temperature increased rapidly during the early morning due to increase of sensible heat flux in EXP2 compared to CTL. The MORUSES with EGIS (EXP3) provided best agreement with observations and represents a reasonable option for simulating the near surface temperature of urban area.

Improvement of MODIS land cover classification over the Asia-Oceania region (아시아-오세아니아 지역의 MODIS 지면피복분류 개선)

  • Park, Ji-Yeol;Suh, Myoung-Seok
    • Korean Journal of Remote Sensing
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    • v.31 no.2
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    • pp.51-64
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    • 2015
  • We improved the MODerate resolution Imaging Spectroradiometer (MODIS) land cover map over the Asia-Oceania region through the reclassification of the misclassified pixels. The misclassified pixels are defined where the number of land cover types are greater than 3 from the 12 years of MODIS land cover map. The ratio of misclassified pixels in this region amounts to 17.53%. The MODIS Normalized Difference Vegetation Index (NDVI) time series over the correctly classified pixels showed that continuous variation with time without noises. However, there are so many unreasonable fluctuations in the NDVI time series for the misclassified pixels. To improve the quality of input data for the reclassification, we corrected the MODIS NDVI using Correction based on Spatial and Temporal Continuity (CSaTC) developed by Cho and Suh (2013). Iterative Self-Organizing Data Analysis (ISODATA) was used for the clustering of NDVI data over the misclassified pixels and land cover types was determined based on the seasonal variation pattern of NDVI. The final land cover map was generated through the merging of correctly classified MODIS land cover map and reclassified land cover map. The validation results using the 138 ground truth data showed that the overall accuracy of classification is improved from 68% of original MODIS land cover map to 74% of reclassified land cover map.

A Study of Factors Influencing of Temperature according to the Land Cover and Planting Structure in the City Park - A Case Study of Central Park in Bundang-gu, Seongnam - (도시공원의 토지피복 및 식재구조에 따른 온도 영향요인 규명 연구 - 성남시 분당구 중앙공원을 사례로 -)

  • Ki, Kyong-Seok;Han, Bong-Ho;Hur, Ji-Yeon
    • Korean Journal of Environment and Ecology
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    • v.26 no.5
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    • pp.801-811
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    • 2012
  • The purpose of this study is to find out how land cover and planting of an urban park influence temperature. Field research on the land cover and planting status was conducted for Bundang Central Park in Sungnam-si. 30 study plots in the site were selected to closely analyze land cover type and planting structure. The temperature was measured 10 times for each plot. Land coverage type, planting type, planting layer structure and green space area (the ratio of green coverage, GVZ) were chosen as factors impacting temperature and statistics were analyzed for the actual temperature measured. Analysis on how the land coverage type influences temperature showed that planting site had a low temperature and that grassland and paved land had a high temperature. When it comes to planting type, the temperature at the land planted with conifers and broad-leaved trees was low, while the temperature at grassland and paved land was high. With regard to planting layer structure, canopy and canopy-underplanting type showed low temperature, while grassland and paved land showed high temperature. An analysis on the relation between green space area and temperature found out that both ratio of green coverage and GVZ had a high level of negative correlation with the temperature measured. According to regression model of green space area and the temperature measured, for every 1% increase in the ratio of green coverage, temperature is expected to lower by $0.002^{\circ}C$. Also, for every $1m^3/m^2$ increase in GVZ, temperature is expected to go down by $0.122^{\circ}C$.

Impacts of Land Cover Change of Tidal Flats on Local Meteorology in Gyeonggi Bay, West Sea of Korea (경기만 갯벌의 지표면 토지피복 변화가 국지기상에 미치는 영향 평가)

  • An, Hye Yeon;Kim, Yoo-Keun;Jeong, Ju-Hee
    • Atmosphere
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    • v.27 no.4
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    • pp.399-409
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    • 2017
  • The impact of land cover changed by tidal flats on local meteorology in Gyeonggi Bay was quantitatively evaluated based on a numerical modeling approach during 18 days (21 June to 9 July 2013). The analysis was carried out using three sets of simulation scenarios and the land cover of tidal flats for each simulation was applied as follows: (1) the herbaceous wetland representing coastal wetlands (i.e., EXP-BASE case), (2) the barren or sparsely vegetated representing low tide (i.e., EXP-LOW case), (3) the water bodies representing high tide (i.e., EXP-HIGH case). The area of tidal flats was calculated as about $552km^2$ (the ratio of 4.7% for analysis domain). During the daytime, the change (e.g. wetlands to water) of land cover flooded by high tide indicated the decrease of temperature (average $3.3^{\circ}C$) and the increase of humidity (average 13%) and wind speed (maximum $2.9m\;s^{-1}$). The changes (e.g. wetlands to barren or sparsely vegetated) of land cover induced by low tide were smaller than those by high tide. On the other hands, the effects of changed land cover at night were not apparent both high tide and low tide. Also, during the high tide, the meteorological change in tidal flats affected the metropolitan area (about 40 km from the tidal flat).

Correlation between the Trend toward Higher Temperature and Land Cover Structure in Haeundae District of Busan in Summer (부산시 해운대구의 하기 도시 고온화 현상과 토지피복 구성과의 상관관계)

  • Yoon, Seong-Hwan;Kim, Seong-Ha
    • Journal of the Korean Solar Energy Society
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    • v.28 no.2
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    • pp.19-27
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    • 2008
  • This study aims at examining the correlation between air temperature and urban structure such as land cover. For this, it measured summer air temperature by using data log type thermometer installed the inside of instrument screen, in the 9 points of elementary school in Haeundae, Busan. The accomplished results of this study are followings. 1) As altitude goes up 100m, air temperature drops to $0.6{\sim}1.0^{\circ}C$. 2) As building coverage ratio increases 10%, air temperature increases $0.3{\sim}0.4^{\circ}C$. 3) As floor space index increases 100%, air temperature increases $0.4{\sim}0.5^{\circ}C$. 4) As artificial coverage ratio increases 10%, air temperature increases $0.1{\sim}0.2^{\circ}C$. 5) As natural coverage ratio increases 10%, air temperature decreases $0.1{\sim}0.2^{\circ}C$.

Examination of Factors Influencing Urban Higher Temperature using E-GIS DB (E-GIS DB를 활용한 도시 고온화 영향인자 검토)

  • Kim, Keum-Ji;Yoko, Kamata;Lee, Jung-Jae;Yoon, Seong-Hwan
    • 한국태양에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.44-49
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    • 2009
  • In this study, we performed urrban climate simulation how both the factor of environmental land and artificial factors influence on the formation of urban temperature. With deducing quantitative data, this study could get more accurate results of the urban temperature using urban climate simulation system. In the case of natural land cover, it appeared that there are effects on the lowering temperature and the lower temperature rate appeared in the water land cover on the whole. This is considered as temperature in water land was low because of the characteristics of water land having evaporation latent heat was high and convective sensible heat was low. In case of building which has building coverage ratio, 5% with 10 floors and building coverage ratio, 15 % with 6 floors, it appears that the temperature in the water land is $33.6^{\circ}C$. In case of building coverage ratio 5%, temperature dropped when buildings has more than 4 stories. This is regarded as the size of building is bigger, the temperature dropped in relatively because of the fluctuation of the rate of solar heat from the land. At the present time, the urban temperature are higher because of various artificial factors in the city. With these results, this study supposed to be a basies of the future studies for considering both the composition of building coverate ratio and floor plan.

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Structural Urban Landscape Changes over Time Series in Gangneung-Si (강릉시 도시 경관 구조의 시계열적 변화 연구)

  • Yeum, Jung-Hun
    • Journal of Environmental Science International
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    • v.30 no.10
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    • pp.779-787
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    • 2021
  • This study analyzes structural landscape changes over a time-series for a small and medium-sized city, Gangneung-Si, based on area and distribution patterns, and according to the type of land cover. Among the types of land cover, the area ratio of urbanized areas increased by 2.02% in the late 2010s as compared to the late 1980s, while there was a decrease of 2.69% in farmland and 0.69% in grassland areas. On analyzing the changes in land cover use by applying the Fragstats program, it was confirmed that landscape changes in urban and management areas were relatively severe according to the Landscape Shape Index, Largest Patch Index, and Aggregation Index. A pattern of concentrated expansion was also found around certain areas. In particular, from the analysis, it was established that the proportion of urbanized area had considerably increased and that the extent of farmland damage to management areas, including planned management areas, was large. Additionally, the Total Core Area generally indicated a reduction in the core areas of farmland and forest within urban and management areas. A medium-sized city showed significant changes besides large cities in terms of landscape structure. The developmental pressure on management areas, in particular, was quite high.

Assessment of hydrological impact by long term land cover change using WMS HEC-1 model in Gyueongan-cheon watershed (WMS HEC-1을 이용한 경안천 유역의 경년 수문변화 분석)

  • Lee, Jun-Woo;Lim, Hyuk-Jin;Lee, Mi-Sun;Kim, Seong-Joon
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2001.10a
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    • pp.330-334
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    • 2001
  • 1. The purpose of this study is to evaluate the hydrologic impact due to temporal land cover changes of Gyueongan-cheon watershed. 2. WMS(Watershed Modeling System) HEC-1 was adopted and the required data such as DEM(Digital Elevation Model), stream network, soil map were prepared, and land cover map was made by using Landsat TM data. 3. Due to the increase of urban area and paddy field, the runoff ratio increased 5.8% during the past decade.

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Spectral Mixture Analysis Using Hyperspectral Image for Hydrological Land Cover Classification in Urban Area (도시지역의 수문학적 토지피복 분류를 위한 초분광영상의 분광혼합분석)

  • Shin, Jung-Il;Kim, Sun-Hwa;Yoon, Jung-Suk;Kim, Tae-Geun;Lee, Kyu-Sung
    • Korean Journal of Remote Sensing
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    • v.22 no.6
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    • pp.565-574
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    • 2006
  • Satellite images have been used to obtain land cover information that is one of important factors for hydrological analysis over a large area. In urban area, more detailed land cover data are often required for hydrological analysis because of the relatively complex land cover types. The number of land cover classes that can be classified with traditional multispectral data is usually less than the ones required by most hydrological uses. In this study, we present the capabilities of hyperspectral data (Hyperion) for the classification of hydrological land cover types in urban area. To obtain 17 classes of urban land cover defined by the USDA SCS, spectral mixture analysis was applied using eight endmembers representing both impervious and pervious surfaces. Fractional values from the spectral mixture analysis were then reclassified into 17 cover types according to the ratio of impervious and pervious materials. The classification accuracy was then assessed by aerial photo interpretation over 10 sample plots.

Relationship between the Birds.Mammals' Distribution and Forest area, Land cover (조류.포유류의 분포와 산림면적, 토지피복과의 관련성)

  • Lee, Dong-Kun;Kim, Bo-Mi;Song, Won-Kyong
    • Journal of Korean Society of Rural Planning
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    • v.15 no.2
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    • pp.19-26
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    • 2009
  • The purpose of this study is to build Island biogeography in the basic concept of landscape ecology in South Korea by draw relationship between the species side of quantitative habitats and forest area surveyed in the national database based on investigation of the 2nd natural environment. In addition, try to present criterion of habitats character category after understanding habitats character of emergence area side of quality habitats based on the type of formatting. Species and forest area relationship analyzed using correlation analysis and simple regression analysis. Also habitat character limited composition ratio of neighboring land cover and analyzed using hierarchical cluster analysis to classify type of habitat. As a result, we found that forest area is correlated with number of species, forests which is bigger than 100ha are more important of increase in species' population. And according to land cover composition ratio, bird's classified types of forest inner species, forest edge species, forest outer species and mammal's classified types of forest inner species, forest general species, forest edge species. We suggest that study of species-forest area relationship and emergence habitat character be used as some management plans of species' conservation, protection and restoration.