• Title/Summary/Keyword: Urban Higher Temperature

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Local Government's Response to Global Warming;Comparison of Seoul and Tokyo (지구온난화에 대한 지방정부의 대응;서울과 동경의 비교)

  • Yoon, Eui-Young
    • Journal of Agricultural Extension & Community Development
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    • v.11 no.2
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    • pp.291-301
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    • 2004
  • As Russian government signs the Kyoto Protocol on November 2004, it will go into effect on Feb. 16 2004. Under the Protocol, 38 industrialized countries are to reduce their combined emissions of six major greenhouse gases, including carbon dioxide and methane, to below 1990 levels during the 2008-2012 period. Korea ratified the Protocol in 2002 and is currently exempt from the reduction measures. It is expected, however, that Korea will be pressured to join the reduction scheme from 2013. Although the Kyoto Protocol is national-level agreement each country's urban governments are expected and have to play important role to make it successful one. It is more so for such mesa cities as Seoul which has experienced rapidly worsening environment recent years. Statistics shows that the annual average temperature in Seoul has increased by $1.5^{\circ}C$ for the last century, which is much higher than the national average. 'Heat Island' effect is not unusual any more in Seoul. This study reviews the key points of the Kyoto Protocol, urban warming phenomena in Seoul and its policy responses. In doing so, this study evaluates Tokyo case as a comparative one. It is found that Seoul needs to develop more concrete and feasible policy measures to get current efforts more effective.

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Analysis of Land Surface Temperature from MODIS and Landsat Satellites using by AWS Temperature in Capital Area (수도권 AWS 기온을 이용한 MODIS, Landsat 위성의 지표면 온도 분석)

  • Jee, Joon-Bum;Lee, Kyu-Tae;Choi, Young-Jean
    • Korean Journal of Remote Sensing
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    • v.30 no.2
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    • pp.315-329
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    • 2014
  • In order to analyze the Land Surface Temperature (LST) in metropolitan area including Seoul, Landsat and MODIS land surface temperature, Automatic Weather Station (AWS) temperature, digital elevation model and landuse are used. Analysis method among the Landsat and MODIS LST and AWS temperature is basic statistics using by correlation coefficient, root-mean-square error and linear regression etc. Statistics of Landsat and MODIS LST are a correlation coefficient of 0.32 and Root Mean Squared Error (RMSE) of 4.61 K, respectively. And statistics of Landsat and MODIS LST and AWS temperature have the correlations of 0.83 and 0.96 and the RMSE of 3.28 K and 2.25 K, respectively. Landsat and MODIS LST have relatively high correlation with AWS temperature, and the slope of the linear regression function have 0.45 (Landsat) and 1.02 (MODIS), respectively. Especially, Landsat 5 has lower correlation about 0.5 or less in entire station, but Landsat 8 have a higher correlation of 0.5 or more despite of lower match point than other satellites. Landsat 7 have highly correlation of more than 0.8 in the center of Seoul. Correlation between satellite LSTs and AWS temperature with landuse (urban and rural) have 0.8 or higher. Landsat LST have correlation of 0.84 and RMSE of more than 3.1 K, while MODIS LST have correlation of more than 0.96 and RMSE of 2.6 K. Consequently, the difference between the LSTs by two satellites have due to the difference in the optical observation and detection the radiation generated by the difference in the area resolution.

Deposition flux of dioxin-like polychlorinated biphenyls(DLPCBs) in urban environment of Busan (도심 지역의 다이옥신류 폴리염화비페닐류의 침적 플럭스)

  • Mun, Hyo-Bang;Lee, Su-Jeong;Choe, Hui-Gu;Ok, Gon
    • Journal of Environmental Science International
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    • v.13 no.5
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    • pp.469-478
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    • 2004
  • Atmospheric bulk (wet and dry) samples were monthly collected in an urban environment (Daeyeon-dong) of Busan over a year, to assess the deposition flux and seasonality of dioxin-like polychlorinated biphenyls (DLPCBs) using stainless steel pots. Deposition fluxes of DLPCBs in bulk samples were determined using high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC/HRMS). Particle deposition fluxes in the urban environment varied from 23 to 98 $mg^2$/year (mean 41 $gm^2$/year). DLPCB deposition fluxes in atmospheric bulk samples ranged from 0.09 to 0.77 ng-$TEQ/m^2$/year (mean 0.35 ng-$TEQ/m^2$/year). Seasonal atmospheric deposition fluxes of DLPCBs were high in winter and low in summer. Atmospheric deposition fluxes of particles and DLPCBs in this study were comparable to or slightly lower values than those of different locations in the world. Monthly DLPCB profiles in deposition bulk samples were similar over a year. Non-ortho PCBs were higher contributions to the total DLPCBs fluxes than mono-ortho PCBs. In particular, PCB 126 had the highest concentrartion (>75%) in all deposition samples, followed by PCB 169 and PCB 156. A highly positive correlation was found among the deposition fluxes of DLPCB species, suggesting the possibility of that the DLPCB contamination originated from one source. The deposition fluxes of DLPCBs were not significantly correlated with temperature and the amount of precipitation even though the summer season with the highest temperature and the largest amount of precipitation showed the lowest DLPCB deposition flux.

Modeling the Impacts of Increased Urbanization on Local Meteorology in the Greater Seoul Area (수도권지역 도시화가 국지기상에 미치는 영향 모델링)

  • Kang, Yoon-Hee;Kim, Yoo-Keun;Oh, In-Bo;Hwang, Mi-Kyoung;Song, Sang-Keun
    • Journal of Environmental Science International
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    • v.19 no.12
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    • pp.1361-1374
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    • 2010
  • The impact of urbanization on local meteorology (e.g., surface temperature, PBL height, wind speed, etc.) in the Greater Seoul Area (GSA) was quantitatively evaluated based on a numerical modeling approach during a 1-month period of 2001 (9 Sep. through 8 Oct. 2001). The analysis was carried out by two sets of simulation scenarios: (1) with the global land use and topographic data from the U.S. Geological Survey (USGS) in 1990s (i.e., LU-USGS case) and (2) with the land use data from the Environmental Geographic Information System (EGIS) along with the 3 sec elevation data from the Shuttle Radar Topography Mission (SRTM) in 2000s (i.e., LU-EGIS case). The extension of urban areas in the GSA (especially, the southern parts of Seoul) accounted for 1.8% in the LU-USGS case and 6.2% in the LU-EGIS case. For the simulations, the surface temperature and PBL height due to urbanization in the LU-EGIS case was higher (the differences of up to $0.1^{\circ}C$ and 36 m, respectively) than those in the LU-USGS case, whereas the wind speed (up to 0.3 $ms^{-1}$) in the former was lower than that in the latter at 1500 LST. The increase in surface temperature due to urbanization in the GSA (especially, the southern parts of Seoul) was led to the strong convergence of air masses, causing the early sea breeze and its rapid propagation to inland locations. In addition, the vertical mixing motion in the extended urban areas for the LU-EGIS case was predicted to be stronger than that for the LU-USGS case and vice versa for the original urban areas.

A Study on Effect of $NO_2$ Photodissociation rate on Ozone concentration from Rural and Urban Area in the Winter (청정지역과 도시지역에서 $NO_2$ 광분해율이 오존농도에 미치는 영향에 관한 연구)

  • 이정주;이동범;윤중섭
    • Journal of Environmental Health Sciences
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    • v.26 no.4
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    • pp.141-147
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    • 2000
  • Due to a rapid in automobiles since the 1980’s, the concentration of NO, and HC has also increased along with cases of VOCs. These air pollutants have created $O_3$ concentration, which cause a harmful effect to the human health. This issue has become a subject of great public interest. For this paper, to compare the concentration of $O_3$, NO, N $O_2$ between the rural and urban area in the winter, the concentrations of each have been measuredevery hour during Jan.~Feb. 2000, 1998, respectively. To calculate the Photochemical Steady State, $\Phi$= $J_{N O_2}$[N $O_2$]/ $k_1$[NO][ $O_3$], temperature and $J_{ N O_2}$ has been determined. The NO concentration in the rural are showed at below 10 ppb while the NO concentration in the urban area showed maximum value of 90~120 ppb. But the $O_3$ concentration in both areas showed less than 30 ppb. The reason is that the N $O_2$ photodissiciation rate is low due to the temperature being below 2$^{\circ}C$ and less than 60 degrees in the solar zenith angle during the winter time, which makes the $O_3$ concentration in both areas, similar in the concentration level. N $O_2$ photodissociation rate in both ares showed maximum value of 3.0mW/$\textrm{cm}^2$. Values of $\Phi$ determined from the rural area was consistently the unity, approaching 1. But values of $\Phi$ determined from the urban was roughly higher than unity, approaching above 1or 2 for clear sky-high sun(10:00~16:00).

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Characteristics of Air Temperature Variations under Different Land Covers during Summer (여름철 토지피복별 기온변화 특성)

  • Kim, Jin-Soo;Park, Jong-Wha;Jung, Gu-Young;Oh, Kwang-Young
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.1
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    • pp.79-88
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    • 2007
  • We investigated the characteristics of temperature variations under different land covers (paddy field, upland, urban park, and urban residential area) during hot summer (July 15 to August 19, 2005). The temperatures were monitored using data loggers at one hour intervals in study sites. The mean temperature generally increased with the distance from edge of paddy fields, being $1.5^{\circ}C$ higher at a site 170-m far from paddy fields than at a paddy field area at 22 h. The mean daily temperatures in the study period followed the ordo. of paddy field $(26.6^{\circ}C)$ < upland $(27.0^{\circ}C)$ < park $(27.5^{\circ}C)$ < residential area $(28.0^{\circ}C)$. The paddy field area has shown remarkable cooling effects compared to the residential area: Mean duration of temperature below $25^{\circ}C$ in the paddy field area was longer (8.6 hrs) than in the residential area; The time to fall to below $25^{\circ}C$ in the paddy field area was sooner (22.4 hr) than in the residential area; Mean daily minimum temperature in the paddy field area was much lower $(2.4^{\circ}C)$ than in the residential area. More research is needed to better clarify the mechanism of cooling effect of a paddy field area by investigating heat balance of a paddy field.

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.

Analysis of Surface Urban Heat Island and Land Surface Temperature Using Deep Learning Based Local Climate Zone Classification: A Case Study of Suwon and Daegu, Korea (딥러닝 기반 Local Climate Zone 분류체계를 이용한 지표면온도와 도시열섬 분석: 수원시와 대구광역시를 대상으로)

  • Lee, Yeonsu;Lee, Siwoo;Im, Jungho;Yoo, Cheolhee
    • Korean Journal of Remote Sensing
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    • v.37 no.5_3
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    • pp.1447-1460
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    • 2021
  • Urbanization increases the amount of impervious surface and artificial heat emission, resulting in urban heat island (UHI) effect. Local climate zones (LCZ) are a classification scheme for urban areas considering urban land cover characteristics and the geometry and structure of buildings, which can be used for analyzing urban heat island effect in detail. This study aimed to examine the UHI effect by urban structure in Suwon and Daegu using the LCZ scheme. First, the LCZ maps were generated using Landsat 8 images and convolutional neural network (CNN) deep learning over the two cities. Then, Surface UHI (SUHI), which indicates the land surface temperature (LST) difference between urban and rural areas, was analyzed by LCZ class. The results showed that the overall accuracies of the CNN models for LCZ classification were relatively high 87.9% and 81.7% for Suwon and Daegu, respectively. In general, Daegu had higher LST for all LCZ classes than Suwon. For both cities, LST tended to increase with increasing building density with relatively low building height. For both cities, the intensity of SUHI was very high in summer regardless of LCZ classes and was also relatively high except for a few classes in spring and fall. In winter the SUHI intensity was low, resulting in negative values for many LCZ classes. This implies that UHI is very strong in summer, and some urban areas often are colder than rural areas in winter. The research findings demonstrated the applicability of the LCZ data for SUHI analysis and can provide a basis for establishing timely strategies to respond urban on-going climate change over urban areas.

Analysis of Meteorological and Radiation Characteristics using WISE Observation Data (WISE 관측자료를 이용한 기상 및 복사 특성 분석)

  • Lee, Hankyung;Jee, Joon-Bum;Min, Jae-Sik;Kim, Sangil;Chae, Jung-Hoon
    • Journal of the Korean earth science society
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    • v.39 no.1
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    • pp.89-102
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    • 2018
  • We analyzed the meteorological and radiation characteristics of Seoul metropolitan area using data from energy flux towers that were installed and operated by the Weather Information Service Engine (WISE). The meteorological and radiation variables included temperature, pressure, wind speed, wind direction, relative humidity, surface temperature, rainfall amount, upward and downward solar radiation, upward and downward longwave radiation, albedo and emissivity from 14 energy flux stations located in the Seoul metropolitan area from July 2016 to July 2017. According to the monthly data during the period, the albedo is low and emissivity is high at the Jungnang station in the urban and opposite at Bucheon station in the suburban area. For a station in natural state, the albedo was higher than urban stations because solar radiation reflects effectively. Relatively high temperatures were shown at stations located in urban area with low albedo and high emissivity, in general. However, temperature was high at Gajwa and Ttukseom stations, the albedo was relatively high due to the station environment surrounded by glass wall buildings and the Han river. In the station located in suburban area, both emissivity and temperature were low. Among these stations, Bucheon station had the highest emissivity values because the surface temperature was relatively lower than that of the suburban area. As a result, the albedo decreased and the emissivity increased at stations in urban areas. Additionally, Seoul metropolitan area had less than $100Wm^{-2}$ of net radiation, which implied that radiation energy could be absorbed in the atmosphere.

Analysis of Environmental Equity of Green Space Services in Seoul - The Case of Jung-gu, Seongdong-gu and Dongdaemun-gu - (서울지역 녹지서비스의 환경형평성 분석 - 중구, 성동구, 동대문구를 사례로 -)

  • Ko, Young Joo;Cho, Ki-Hwan;Kim, Woo-Chan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.2
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    • pp.100-116
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    • 2019
  • Urban green spaces, as a means to mitigate social problems and environmental risks, are getting more attention in evaluating urban environment. The inequity of green space distribution is becoming a major issue in urban planning and management. This study investigated the characteristics of green space in 3 districts (Jung-gu, Dongdaemun-gu, Seongdong-gu), that are composed of 46 administrative divisions in central Seoul, to analyze the environmental equity of urban green spaces. The correlations between the amount of green space, including the coverage of street trees, and the socioeconomic status of each administrative division were analyzed. To deduce the effects of plant coverage on the urban temperature regime, the relationship between the normalized difference of vegetation index (NDVI) and land surface temperature (LST) was analyzed. The research revealed that the mean NDVI of an administrative division was negatively correlated with the percentage of basic living recipients and disabled people. The LST of a division with low NDVI was higher due to the lack of green coverage. Such environmental inequities were closely related to residential building type, which was strongly affected by the economic status of residents. The LST of an apartment area was $2.0^{\circ}C$ lower than that of single-family houses and multi-housing areas. This is expected as the average NDVI of the apartment area was more than twice as high as the other environments considered in this study. The inequity can be exacerbated without urban planning which is deliberately designed to reduce it.