• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.1
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• pp.18-27
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• 2009

The purpose of this study is to understand the scale of temperature change following large-scale urban developments in paddy fields to present possible measures to preserve suburban area paddy fields and to lower the scale of temperature increase after developing paddy fields in urban areas. The study was conducted in Bupyeong and Bucheon of Incheon Metropolitan City. The satellite image($1989{\sim}2000$) before and after the development of old paddy fields were used to analyze the land surface temperature changes according to the land use types. Building coverage, green coverage, non-permeable pavement coverage, and floor area ratio(FAR) were selected as the factors that influence urban temperature changes and the temperature estimation model was constructed by using correlation and regression analyses. The before and after satellite images of Bupyeong and Bucheon were classified into forests, greens and plantations, paddy fields, unused lands, and urban areas. The results indicate that most of the paddy fields that existed in the center of Bupyeong and Bucheon were converted into unused lands which were undergoing construction to become new urban areas. The difference between the surface temperatures of May 17th, 1989 and May 7th, 2000 was analyzed to reveal that most land converted from paddy fields to unused lands or urban areas saw an increase in surface temperature. Han River was used as a comparison to analyze the average surface temperature changes($1989{\sim}2000$) in former paddy fields. The scale of temperature changes were: $+1.6697^{\circ}C$ in urban parks; $+2.5503^{\circ}C$ in residential zones; $+2.9479^{\circ}C$ on public lands, $+3.0385^{\circ}C$ in commercial zones, and $+3.1803^{\circ}C$ in educational zones. The correlation between building coverage, green coverage, non-permeable pavement coverage, or floor area ratio(FAR) and surface temperature increases was also analyzed. The green coverage to temperature increases, but building coverage, non-permeable pavement coverage, and floor area ratio(FAR) had no statistically significant temperature increases. The factors that influence urban temperature changes were set up as independent variables and the surface temperature changes as dependent variables to construct a surface temperature change model for the land use types of former paddy fields. As a result of regression analysis, green coverage was selected as the most significant independent variable. According to regression analysis, if farmland is converted into an urban area, a temperature increase of $+3.889^{\circ}C$ is anticipated with 0% green coverage. The temperature saw a decrease of $-0.43^{\circ}C$ with every 10% increase of green coverage.

• Korean Journal of Remote Sensing
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• v.35 no.6_4
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• pp.1403-1415
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• 2019

Urban population growth and consequent rapid urbanization involve some thermal environmental problems in the cities. Monitoring of thermal environments in urban areas such as hot spot analysis is required for effective actions to resolve these problems. This study selected 14 dongs and surrounding administrative districts of Sejong city as study areas and analyzed the characteristics of changes in surface temperature due to the urban expansion in the summer from 2013 to 2018. In the study, the surface temperature distributions in the study areas were plotted using surface temperature values from Landsat 8 and NDVI (Normalized Difference Vegetation Index) and NDBI (Normalized Difference Built-up Index) based on KOMPSAT 2/3 data, and the patterns of surface temperature changes with urban expansion were discussed using the estimated NDVI and NDBI. In particular, the distinct urbanization in the study areas were selected for case studies, and the cause of the changes in the hot spots in the regions was analyzed using high-resolution KOMPSAT images. This study results present that hot spots appeared in urbanized regions within the study areas, and it was plotted that the lower the NDVI values and the higher the NDBI values indicate the temperature values are high. The land surface temperature and satellite-based products were used to divide the study areas into continuously urbanized regions and rapidly urbanized regions and to identify the different characteristics depending on land covers. In the regions with distinct surface temperature changes by urbanization, the analysis using high-resolution KOMPSAT images as presented in this study could provide effective information for urban planning and policy utilization in the future.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.1
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• pp.16-27
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• 2022

Due to climate change, temperature is rising worldwide. Since rapid growth has been achieved focused on cities, South Korea is experiencing serious environmental problems such as heat island and air pollution in urban areas. To solve this problem, the central and each local government are actively promoting tree planting campaigns. This study quantitatively calculated changes in green areas and vegetation of Gumi by the tree planting campaign, and analyzed the temperature changes accordingly. For the target area, the green area, vegetation index, and ground temperature were calculated for 4 different time periods using the given Landsat satellite images. As a result of the study, the green area of was increased by 7.24km² and 4.93km² for two regions, respectively. Accordingly, the vegetation index increased by 0.14 to 0.16, and the temperature decreased by 0.8 to 1.2℃. The Tree planting campaign not only plays a role in lowering the temperature of the city but also does various roles such as air purification, carbon absorption, and providing green rest areas to citizens. Therefore the campaign should be carried out continuously.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.4
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• pp.39-44
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• 2009

To analysis the LST distribution of Jeju island, remote sensing techniques using Landsat TM band 6 data were used. In this study, we made the LST distribution map based on the NASA. The study areas are the Jeju and Seogwipo cities of the Jeju Island. And we analyzed the correlation between the LST and NDVI which was calculated from the Landsat TM band 3 and ban 4. From the result, we found that the coefficients of the correlation were -0.77 and -0.74 on the Jeju and the Seogwipo cities, respectively. Finally, from the correlation between the land cover and LST, we also found that an inverse relationship between the LST and NDVI was exist.

• Journal of the Korean Geotechnical Society
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• v.29 no.8
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• pp.75-84
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• 2013

Soil freezing is a phenomenon arising due to temperature difference between atmosphere and ground, and physical properties of soils vary upon the phase change of soil void from liquid to solid (ice). A heat-transfer mechanism for this case can be explained by the conduction in soil layers and the convection on ground surface. Accordingly, the evaluation of proper thermal properties of soils and the convective condition of ground surface is an important task for understanding freezing phenomenon. To describe convection on ground surface, simplified coefficient methods can be applied to deal with various conditions, such as atmospheric temperature, surface vegetation conditions, and soil constituents. In this study, two methods such as n-factor and convection coefficient for the convective ground surface boundary were applied within a commercial numerical program (TEMP/W) for modeling soil freezing phenomenon. Furthermore, the numerical results were compared to laboratory testing results. In the series of the comparison results, the convection coefficient is more appropriate than n-factor method to model the convective boundary condition.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.1013-1022
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• 2010

In this paper, we propose a C-band radiometer for remote sensing of land surface temperature and present its experiment results using asphalt as target. Total power type is selected for high sensitivity and low power consumption, super-heterodyne type is selected for stable high gain. A radiometer designed at 5.1 GHz to have operating bandwidth of 110 MHz has system gain of 59 dB, noise figure of 2.7 dB and receiving sensitivity of 0.45 K. We have measured surface temperature on asphalt by using implemented system and thermometer. Analysis data of each measurement results show that a radiometer operates linearly with output voltage variation rate of 6 $mV/^{\circ}C$. As a result, we verified validity of a developed C-band radiometer for remote sensing of land surface temperature.

• Journal of the Korean Geotechnical Society
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• v.38 no.3
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• pp.17-26
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• 2022

Domestic district heating system needs safety management guidelines using the change of surface temperature to detect damages to buried heat pipes. This paper performed numerical analyses on the temperature change of ground surface due to the burial and leakage of heat pipes. Temperature difference between the ground surface above the buried heat pipes and the surrounding surface rises to a crescendo between 3 am and 8 am. It is more significant in winter rather than in summer. Low groundwater level magnifies the temperature increase of the ground surface by the heat pipe, which is smaller in the asphalt pavement than in the bare soil. Without leakage of the buried heat pipe, the temperature increment on the ground surface by the heat pipe is within 3.0℃ in the bare soil and 3.5℃ in the asphalt pavement. Leakage of the supply heat pipe in the bare soil increases the temperature on the ground surface gradually in the summer but rapidly in the winter. Asphalt pavement shows a lower increment and increasing rate of the temperature on the ground surface due to pipe leakage than bare soil surface. And leakage on both sides of the supply pipe takes 1-2 days for the temperature difference from the surrounding soil surface to reach 10℃.

• Journal of Wetlands Research
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• v.19 no.1
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• pp.122-131
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• 2017

Remotely sensed satellite data is easier to collect and better to represent local phenomenon than a site data. So they can contribute to the activation and development of many research. However, it is necessary to improve spatial resolution suitable for application in the area of complex topography such as the Korean Peninsula. In this study, finer resolution Land Surface Temperature (LST) was downscaled from 4 km to 500 m by combining GOCI with MI data of Communication, Ocean and Meteorological Satellite (COMS). It was then statistically analyzed with LST data observed from the ASOS sites to validate its applicability. As a result, it was found that the errors decreased and correlation increased at the most validation sites, also the spatial distribution analysis showed a similar tendency but it expressed the complicated terrain better. This study suggests possibility of expanding the application range of COMS by producing finer resolution data available in various studies.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.53-53
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• 2023

본 연구에서는 토양의 동결-융해 상태 구분을 위해 영상레이더(Synthetic Aperture Radar) 자료를 활용해 지표상태인자(Surface State Factor, SSF)를 산정하고, 관측 토양수분 자료 및 지표면 온도(Land Surface Temperature, LST) 자료와의 비교를 통해 SSF의 정확도를 분석하였다. SSF 산정은 용담댐 유역을 포함한 인근 40×50 km²의 영역(N35°35'~36°00', E127°20'~127°45')에 대한 9개의 토양수분 관측지점(계북, 천천, 상전, 안천, 부귀, 주천, 장수읍, 진안읍, 무주읍)을 대상으로 연구를 수행하였으며, 이를 위해 2015년부터 2019년까지의 해당 지점의 토양수분 관측자료와 Sentinel-1A Interferometric Wide swath (IW) 모드의 Ground Range Detected (GRD) product를 구축하여 활용하였다. SSF 자료의 정확도 분석을 위한 토양수분 관측지점에 대한 LST 자료는 인근 7개 기상관측소 지점(전주, 금산, 임실, 남원, 장수, 함양군, 거창)의 관측자료로부터 역거리가중법을 통해 산정하였다. Receiver Operating Characteristic (ROC) 분석을 통한 겨울철(12-2월)의 SSF 산정 정확도를 평가한 결과, 지표면 온도 자료와의 평균 정확도는 0.75(0.48-0.87)로 나타났다. 그러나, 지표면 온도가 0℃ 이상일 때 SSF가 동결 상태로 나타나는 오차가 관측되었으며, 이는 여름철 후방산란계수의 평균값과 겨울철 후방산란계수의 평균값을 통해 산정하는 SSF 산정 수식의 특성 때문으로 이 값의 조정을 통해 오차를 개선할 수 있음을 보였다.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.553-554
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• 2009

This paper introduces the new measuring method for the water level and the scour. The method measures temperature between water and ground by temperature sensors. It analyzes the change of temperature. It estimates the water level and the ground level, and calculates the scour. If the temperature sensors installed until the top of the pier, it can measure the water level.