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Water quality deterioration due to outdoor loading of livestock manure requires efficient management of outside manure piles (OMPs). This study was designed to investigate OMPs using unmanned aerial vehicles (UAVs) for efficient management of non-point source pollution in agricultural areas. A UAV was used to acquire image data, and the distribution and cover installation status of OMPs were identified through ortho-images, the volumes of OMP were calculated using digital surface model (DSM). UAV- and terrestrial laser scanning (TLS)-derived DSMs were compared for identifying the accuracy of calculated volumes. The average volume accuracy was 92.45%. From April to October, excluding July, the monthly average volumes of OMPs in the study site ranged from 64.89 m3 to 149.69 m3. Among the 28 OMPs investigated, 18 were located near streams or agricultural waterways. Establishing priority management areas among the OMP sites distributed in a basin is possible using spatial analysis, and it is expected that the application of UAV technology will contribute to the efficient management of OMPs and other non-point source pollutants.

Since outdoor compost piles (OCPs) contain large amounts of nitrogen and phosphorus, they act as a major pollutant that deteriorates water quality, such as eutrophication and green algae, when the OCPs enter the river during rainfall. In South Korea, OCPs are frequently used, but there is a limitation that a lot of manpower and budget are consumed to investigate the current situation, so it is necessary to efficiently investigate the OCPs. This study compared the accuracy of various machine learning techniques for the efficient detection and management of outdoor compost piles (OCPs), a non-point pollution source in agricultural areas in South Korea, using unmanned aerial vehicle (UAV) images. RGB, multispectral, and thermal infrared UAV images were taken in August and October 2019. Additionally, vegetation indices (NDVI, NDRE, ENDVI, and GNDVI) and surface temperature were also considered. Four machine learning techniques, including support vector machine (SVM), decision tree (DT), random forest (RF), and k-NN, were implemented, and the machine learning technique with the highest accuracy was identified by adjusting several variables. The accuracy of all machine learning techniques was very high, reaching values of up to 0.96. Particularly, the accuracy of the RF method with the number of estimators set to 10 was highest, reaching 0.989 in August and 0.987 in October. The proposed method allows for the prediction of OCP location and area over large regions, thereby foregoing the need for OCP field measurements. Therefore, our findings provide highly useful data for the improvement of OCP management strategies and water quality.

The accuracy of land surface temperatures (LSTs) acquired by an unmanned aerial vehicle (UAV) was verified by comparison with in-situ LSTs of various land cover materials at the Changwon National University Campus, Changwon City, South Korea. UAV imaging and in-situ measurements were performed on 31 July and 2 August 2019. During the in-situ measurements, LST was measured at 160 points using an infrared thermometer. The linear regression model between the UAV and in-situ measurements exhibited a very high correlation on both days, with R2 values greater than 0.7004. The root mean square error (RMSE), however, was 4.030 °C on 31 July and 5.446 °C on 2 August and it also varied depending on the land cover type. These results may depend on various factors, such as the field of view and performance of the TIR (Thermal infrared radiance) camera, as well as the weather and atmospheric conditions. Accurately diagnosing the thermal characteristics of urban areas based on the spatial elements can be used to accurately analyze the thermal characteristics of urban areas and to make effective policy decisions. Techniques for verifying and improving the accuracy of UAV TIR LST data for various land cover materials are required to enable precise investigation of the thermal characteristics of urban areas.

We analyzed the relationship between changes in land cover and the time-series trend of temperature using 40 years’ worth of data (1980–2019) from 38 weather stations in South Korea to establish mitigation strategies for the rising temperature and heat island effect in urban areas. Changes in temperature were estimated by analyzing the time-series trend slope using daily mean temperature data. Stations with a high trend slope showed a mean temperature rise of 2 °C over the study period, and those with a low trend slope had a mean temperature rise of 0.5 °C. In land cover change, each study site was classified into three categories: areas with heavy urbanization, areas with few land-cover changes, and decreased rural and forest areas. A correlation analysis between the land-cover change and temperature trend slope revealed a positive correlation between urban areas and the trend slope and a negative correlation between forest areas and the trend slope. The expansion of urban areas resulting from the development of forest areas was identified as the cause of the long-term increase in the urban temperature. These results will serve as useful data in the urban and environmental planning phase for mitigating urban heat island effects.

The purpose of this study is to analyze reasonable green area ratios for mitigating urban heat island considering various land use types. Land uses of 5 types such as single residential, multi residential, commercial area, public facility, and industrial area were considered. Green areas were extracted from the tree attribution of land cover. Effect of urban heat island was analysed by the surface temperature of ASTER thermal infrared radiance scanned daytime and nighttime. Mitigation effect of green area at daytime was higher than nighttime. Surface temperature of green area was low in single residential at daytime. But the difference of surface temperature by each land use type was small. The effect of surface temperature mitigation of green area was lower in industrial area. The results of reasonable green area ratios for mitigating urban heat island indicate that surface temperature was the lowest with green area ratio of 40~50% in single residential, multi residential, and commercial area at daytime. Surface temperature of nighttime was not changed much by green area ratios. Therefore, the results of this study will be suggested in urban development planning to construct effectively green area for mitigating urban heat island.

The aim was to identify microclimate characteristics in relation to ground cover in green areas and the reflectivity of building coating materials. Furthermore, microclimate modeling of temperatures was conducted using ENVI-met, to analyze the effects of improved thermal environments based on increased green areas and increased reflectivity of exterior coatings. The accuracy of ENVI-met was validated through comparisons with field temperature measurements. The RMSE deviation of the predicted and actual field temperature values was 3–6°C; however, the explanatory power was as high as 60%. ENVI-met was performed for commercial and single residential areas that have high densities of artificial cover materials, before and after changes related to development of green areas and to increase in the reflectivity of coating materials. The results indicated that both areas exhibited distinct temperature reductions due to the creation of green spaces. When the reflectivity of the coating material was increased, a temperature increase was observed in all land-use types. Therefore, in order to improve the thermal environment of complex urban areas, it is necessary to improve green-area development and to use high-reflectivity ground and building cover materials, while taking into account the spatial characteristics of land-use types and their surrounding areas.

Long-term monitoring was performed between December 2017 and November 2018 on cool roof–applied building (CR) and non-cool roof–applied building (NCR). The study was conducted in Changown city South Korea, which has a humid subtropical climate, to identify the temperature reduction effect on different building layers (rooftop surface, ceiling surface and air, and room air). With respect to the temperature reduction effect by layer according to the application of a cool roof (NCR−CR), the rooftop surface temperature showed an increasing temperature reduction effect with increase in air temperature. Ceiling surface and air temperatures showed similar temperature reduction effects in summer and winter, whereas room air temperature showed greater temperature reduction in the winter than in summer. This finding was contrary to the results for room air temperature in the winter reported in previous studies. In conclusion, the present study confirmed that applying cool roofs on buildings located in humid subtropical climates has more pronounced effects in terms of reduced indoor temperature (ceiling surface, ceiling air, and room air) in winter than in summer. The long-term measurement results produced in this study may be used as basic data for establishing criteria for cool roof performance and product selection in South Korea.

This research measures and compares on-site net radiation energy, air temperature, wind speed, and surface temperature considering various spatial characteristics with a focus on land use types in urban areas in Changwon, Southern Gyeongsangnam-do, to analyze the accuracy of an ENVI-met model, which is an analysis program of microclimate. The on-site measurement was performed for three days in a mobile measurement: two days during the daytime and one day during the nighttime. The analysis using the ENVI-met model was also performed in the same time zone as the on-site measurement. The results indicated that the ENVI-met model showed higher net radiation than the on-site measurement by approximately during the daytime whereas the latter showed higher net radiation energy by approximately during the nighttime. The temperature was found to be much higher by approximately in the on-site measurement during both the daytime and nighttime. The on-site measurement also showed higher surface temperature than the ENVI-met by approximately . In terms of the wind speed, there was a significant difference between the results of the ENVI-met model and on-site measurement. As for the correlation between the results of the ENVI-met model and on-site measurement, the temperature showed significantly high correlation whereas the correlations for the net radiation energy, surface temperature, and wind speed were very low. These results appear to be affected by excessive or under estimation of solar and terrestrial radiation and climatic conditions of the surrounding areas and characteristics of land cover. Hence, these factors should be considered when applying these findings in urban and environment planning for improving the microclimate in urban areas.

Spatiotemporal air and land surface temperature (LST) characteristics were analyzed based on urban spatial patterns for Changwon City, South Korea. Twelve ASTER (Advanced spaceborne thermal emission and reflection radiometer) Thermal infrared radiance (TIR) images during the daytime and nighttime from June to September, 2012&ndash, 2014 were used for LST analysis. Air temperature was measured at five meteorological stations. The landcover type, elevation, and location of the meteorological measurement stations were the spatial patterns. The differences among the mean LST for each landcover material were the maximum of 8 &deg, C and 1 &deg, C during the daytime and nighttime, respectively. The LST decreased with increasing built-up area ratio, most prominently in July, but less so with increasing forest area for the same area ratios. The changes of urban temperature according to the spatial pattern were found to be different in each period, and there were some differences from previous studies. This is because the thermal characteristics differ depending on the geographical location, climatic conditions, and building environment of the cities. Therefore, to mitigate the urban heat island continuously, it should be applied to urban planning considering the relationship between spatial patterns and urban temperature, and the urban environment should be considered rather than directly using the results of previous studies.

The purpose of this study is to analyze water cycle area ratio and spatial evaluation of water cycle in urban area of Changwon-si, Gyeongsangnam-do. Water cycle area ratio are analyzed by using spatial data of land-cover and land-use, and Hot spot analysis of GIS program was used for spatial evaluation of water cycle. The results are as below. Firstly, the high water cycle area ratio areas were forests, parks, and rivers, but urban areas covered asphalt and concrete were low under 40%. Public institutions and co-residential of urban areas were higher than others because of high area ratio of pervious land-cover. Spatial evaluation of water cycle was analyzed to vulnerable areas there are dense residential and commercial area. These areas are really occurring frequently flooding and immersion, therefore, is required water management facilities and improvement of land-cover from impervious to pervious. In the future, it will require additionally analysis of water cycle area ratio supplemented data of water management facility and ground water.

The purpose of this study is to evaluate air ventilation using wind patterns of MetPhoMod program at nighttime focused on Changwon-si, Gyeongsangnam-do. Evaluation indices of air ventilation are wind resistant and retention used by results of each wind speed and diversity. The results are as follows. Vulnerable areas of air ventilation are Bonglim-dong, Bansong-dong, Yongji-dong and so on. In high-rise apartment, commercial area and single residential area of Yongji-dong, Sangnam-dong and Sapa-dong, wind is stagnated by high buildings. Therefore, these areas should construct urban spaces to circulate the wind. And to inflow persistingly the fresh wind generated in a rural area, we think that the construction of wind corridor is suggested by development plan and policy wind corridor.

The purpose of this study is to investigate the characteristics of urban heat island considering urban space at nighttime. We used to analyze landuse and landcover data of 1:1,000 scale, DTM, and surface temperature extracted ASTER image satellite of nighttime. According to the analytical results, heat intensity in single-family residential is higher than that in industrial area, public facility area, and commercial area because the anthropogenic heat by energy consumption is released. Likewise, the temperature difference were big in the buildings of industrial area depending on operating hours. Meanwhile, green and river area had cooling impacts mitigating the urban heat island. Therefore, we have to mitigate heat intensity through constructing green space and waterfront area. As mentioned above, we think that the results of this study will be used as base data for effective spatial planning when formulating development planning to mitigate urban heat island at nighttime.

The objective of this paper is to analyze the GIS-based water cycle system: rainfall, evapotranspiration, surface run-off of Gyeongsanam-do for the effective rainwater management. The rainfall(1999~2008) analyzed by a spatial interpolation method, showed relatively higher amount in Hadong-gun, Sanchung-gun, and Sacheon-gun on 2011년 3월 11일 접수 Received on March 11, 2011 / 2011년 5월 2일 수정 Revised on May 2, 2011 / 2011년 5월 30일 심사완료 Accepted on May 30, 2011 1 창원대학교 환경공학과 Dept. of Environmental Engineering, Changwon National University 2 경상남도 보건환경연구원 Gyeongsangnam-do Provincial Institute of Health and Environment ※ 연락저자 E-mail : pureguy55@nate.com 경상남도의 효율적 빗물관리를 위한 GIS 기반 물순환 체계 분석 / 이택순.송봉근.한치복.박경훈 83 the southwest coast than in Changnyeong-gun, Miryang-si, and Changwon-si in the mideast inland. The evapotranspiration was calculated by the three independent variables: air temperature, landuse, and NDVI(normalized difference vegetation index). The analysis showed that Namhae-gun had the highest evapotranspiration of 93.71mm, and Jinhae-si and Changwon-si had the lowest values of 81.78mm and 84.37mm. The surface run-off was analysed by a run-off equation based on the SCS hydrologic soil classification and landuse. The amount of surface run-off showed that Hadong-gun had the highest value, of 90.40mm, and Geochang-gun had the lowest, of 46.69mm. The analysis results of the GIS-based water cycle system will be used to support the establishment of the effective rainwater management plan in Gyeongasngnam-do.

This study compared Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) surface temperature data within situmeasurements to validate the use of ASTER data for studying heat islands in urban settings with complex spatial characteristics. Eight sites in Changwon, Korea, were selected for analyses. Surface temperature data were extracted from the thermal infrared (TIR) band of ASTER on four dates during the summer and fall of 2012, and correspondingin situmeasurements of temperature were also collected. Comparisons showed that ASTER derived temperatures were generally 4.27°C lower than temperatures collected byin situmeasurements during the daytime, except on cloudy days. However, ASTER temperatures were higher by 2.23–2.69°C on two dates during the nighttime. Temperature differences between a city park and a paved area were insignificant. Differences between ASTER derived temperatures and onsite measurements are caused by a variety of factors including the application of emissivity values that do not consider the complex spatial characteristics of urban areas. Therefore, to improve the accuracy of surface temperatures extracted from infrared satellite imagery, we propose a revised model whereby temperature data is obtained from ASTER and emissivity values for various land covers are extracted based onin situmeasurements.