• Journal of the Korean Regional Science Association
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• v.35 no.4
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• pp.61-73
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• 2019

Urban development and densification have led to the Urban Heat Island Effect, in which the temperature of urban space is higher than the surrounding areas, and the intensity is increasing with climate change. In addition, when the city's air temperature rises in summer, low-income, elderly population, and socially vulnerable people who have health problems lack the ability to cope with the elevated heat environment. Therefore, this study aimed to identify the urban heat island area of Seoul through Hotspot analysis, which is a spatial statistics technique, and explored physical environments, demographic and socioeconomic characteristics of urban heat island effect areas using logistic regression models. This study performed urban heat island hotspot analysis using the average air temperatures of the 423 administrative dongs in Seoul. Analysis results identified that the urban heat islands were concentrated in Jung-gu, Jongno-gu, Yongsan-gu, and Yeongdeungpo-gu. Logistic regression analysis results indicated that urban heat island areas of Seoul were affected by residential floor area ratio, commercial facility floor area ratio, overall floor area ratio, impervious surface ratio, and normalized difference vegetation index(NDVI). In addition, as a result of analyzing the vulnerable area of thermal environment considering the demographic and socioeconomic characteristics of the heat island area, urban heat island areas of Seoul were significantly associated with the proportion of low-income elderly living alone. The result of this study provided useful insights for urban thermal environmental design and policy development that could improve the thermal environment for the socially disadvantaged urban population.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.4
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• pp.131-142
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• 2017

This study aims to create a Local Climate Zone(LCZ) map of Seoul by using World Urban Database and Access Portal Tools(WUDAPT) protocol, and to analyze the characteristics of the Seoul LCZs. For this purpose, training samples of 17 LCZ types were collected by using Landsat images and Google Earth. LCZ Classification and Filtering were performed by SAGA GIS. An ArcGIS was used to analyze the characteristics of each LCZ type. The characteristics of the LCZ types were analyzed by focusing on building surface fraction ratio, impervious surface fraction ratio, pervious surface fraction ratio, building stories and air temperature. The results show that one filtering was found to be most appropriate. While Yangcheongu and Yeongdeungpogu with the higher annual and maximum mean air temperature than other areas have the higher rate of LCZ 3(compact low-rise) and LCZ 4(open high-rise), Jongnogu, Eunpyeonggu, Nowongu and Gwanakgu with the lower value have the higher rate of LCZ A(Dence trees). The values of building surface fraction ratio, impervious surface fraction ratio and building stories of each LCZ were included in the range of WUDAPT for most LCZs. However, the values of pervious surface fraction ratio were out of the range, in particular, in the LCZs 4~6 and 9~10. This study shows the usability and applicability of the WUDAPT methodology and its climate zone classification used in many countries as a basic data for the landscape planning and policy to improve the thermal environment in urban areas.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.77-83
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• 1983

Effects of rice straw application (particularly application method; surface placement and deep placement) on the biological nitrogen fixing activity of paddy fields and on the growth of rice plant have been investigated by the lysimeter experiment with Aragawa alluvial soil and Tochigi ando soil. 1. Nitrogen fixing activity of plow layer (0~1cm) was increased by the rice straw application, notably by the phototrophs, both deep placement and surface placement, between 1 and 2 months of initial growth stage of rice plant. 2. Surface placement method stimulated the nitrogen fixing activity more significantly them the deep placement method, and also showed good effects on the growth of rice plant. 3. The increased of effect on the nitrogen fixing activity of surface placed area was found to be originated from the applied rice straw and its neigh bouring area. 4. Nitrogen fixing activity of surface placed rice straw was rather promoted by the application of herbicides (2, 4, 6-arichlorophenyl ether) than the non-applicated plot.

• Korean Journal of Social Welfare
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• v.66 no.2
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• pp.51-74
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• 2014

This study aimed to examine a multiple mediator model in which stresses affect self-criticism. The self-criticism, in turn seemed to affect the feelings of loneliness, and this had an effect on over 65 years living alone. Furthermore, whether social support had any moderating effects in the pathway from the loneliness to suicidal ideation on our pass model were also investigated. Data were collected from 572 samples of persons 65 years of age and older living alone in Seoul. For the analyses of the mediating effects and moderating effects, structural equation modeling was used. The results were as follows. First, the pass model was identified to fit the observed data. This mean that self-criticism increased as stress rises, the increased levels of self-criticism increased loneliness, and the increased levels of loneliness increased the levels of suicidal ideation. Second, social support moderated the relation between loneliness and suicidal ideation on our model. These results suggested that interventions which deal with loneliness and suicidal ideation were needed, in order to reduce suicidal ideation caused by the stress. These imply, additionally, that when social workers try to reduce the suicidal ideation, they should consider the levels of social support at work as influences.

• Korean Journal of Environmental Biology
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• v.18 no.3
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• pp.337-345
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• 2000

The flora and vegetation of salt marsh region in Nonhyun-dong, Incheon were investigated from June 1999 to June 2000. The surveyed region includes the several abandoned salt farms and natural salt marshes developing along the intertidal zone at the stream of the Sorae Inlet, Yellow Sea and is going to be constructed a costal ecopark. In this survey 14 species of halophytes were collected in the region, among them Suaeda maritima is the most common one, Salicornia herbacea, Artemisia scoparnia and Aster tripolium are also observed popularly. The flora of the abandoned salt farms is very similar to that of the natural salt marshes. However, the bank areas between the abandoned salt farms and the natural salt marshes showed more richness of species diversity including 21 naturalized plants. The vegetations on the natural salt marshes are mainly composed of Suaeda maritima -Artemisia scoparnia and Suaeda maritima communities. On the other hand, various plant communities were investigated in the abandoned salt farms such as Suaeda maritima-Salicornia herbacea, Phragmites communis-Typha angustata, Suaeda asparagoides -Suaeda maritima and Phragmites communis communities. Based on the plant physiognomy and species diversity, the region can be divided into three types of area for conservation, that is, the area composed of well-developed vegetation, disturbed one by human activities and plant withering area. Futhermore, according to the construction of the costal ecopark in the region the conservation scheme for each area was discssed.

• Korean Journal of Weed Science
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• v.10 no.2
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• pp.99-102
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• 1990

Pearl millet (Pennisetum americanum (L.) Leeke) has been found as a promising new forage crop of higher quality and yield in Korea since 1985. The objective of the study was to select preemergence herbicides for weed control in growing pearl millet in order to reduce production cost and with increased yields. Propazine (Milogard 4L) was the best in controlling weeds without its phytotoxicity at the standard application rate, and with the highest survival rate of seedlings of peal millet "Suwon 1" hybrid. Sprayings with Atrazine and Simazine caused lower survival rate of peal millet and with their light phytotoxicity as compared with manual weeding and Propazine spraying. Alachlor killed pearl millet seedlings almost completely. Pendimethalin also was not good for weed control of peal millet due to its severe phytotoxicity and with very low survival rate of pearl millet seedlings.

• Journal of Environmental Impact Assessment
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• v.25 no.3
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• pp.222-232
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• 2016

Water Footprint is utilized to analyze direct and indirect water consumption for sustainable water resource management. This study aims to understand potential applicability of water footprint concept by analyzing the status of water consumption and related water policies in Seoul. We analyzed a direct gray water footprint and the blue water footprint in Seoul affected by the social and economic characteristics of the consumers in the city. In particular, in order to analyze the blue water footprint represented by both surface and underground water for the provision and consumption of products, we calculated the actual water consumptions of surface and underground water for 25 districts in Seoul. Our analysis in consideration of population and households indicates that Jung-gu has the highest blue water footprint followed by Jongro-gu, Gangnam-gu, Yongsan-gu, and Seocho-gu. Gray water footprint was calculated by estimating the amount of water for purifying wastewater to meet the water quality standard (above BOD 3.5ppm) for each district. As a result, Jung-gu has the highest gray water footprint, followed by Jongro-gu, Gangnam-gu, Yongsan-gu, Seocho-gu, and Youngdeungpo-gu. Our study suggests the potential value of using water footprint concept to complement the current limitations of water use management focusing on water supply control. We expect that our analysis will provide an important basis for considering water use management which is economically and socially more resilient and sustainable.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.2
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• pp.105-121
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• 2011

The operation of tidal power facility may induce severe changes of water quality in Shihwa Lake. Current water quality data are quite important to water quality management policy of Shihwa Lake. Thus, the water quality data of Shihwa Lake and its adjacent sea in 2010 were presented to characterize the temporal and spatial changes of water parameters such as pH, SS, DO, COD, dissolved nutrients, chlorophyll-a, TN and TP. Highest levels of water quality parameters were observed near the Shihwa and Banweol industrial complexes and the levels of water quality parameters were on a decreasing trend to those near the water gate. It suggests that the horizontal distributions of water quality levels are mainly controlled by the supply of fresh water from streams and the inflow of outer seawater by operation of water gate. Although the higher concentrations of TN and TP were observed in the location being affected by Sorae port, the levels of water quality parameters in outer sea of Shihwa Lake were lower than those in Lake. In summer season, hypoxic condition was well developed in bottom water by strong stratification and active decomposition of organic matter. Thus, the vertical distributions of dissolved nutrient, TN and TP concentrations showed the concentrations to be higher in bottom seawater than those in surface seawater whereas the vertical distributions of chlorophyll-a, COD and POC concentrations showed the concentrations to be higher in surface seawater than those in bottom water. Results of Pearson's correlation matrix for surface seawater demonstrated that salinity showed negatively good correlation with not only dissolved nutrients except for ammonium but chlorophyll-a, COD and POC This result indicates that the supply of dissolved nutrients through several streams might significantly affect phytoplankton bloom and increase of COD concentration in surface seawater.

• Korean journal of applied entomology
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• v.41 no.1
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• pp.27-32
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• 2002

Biological control of thrips with a predatory bug species, Orius sauteri Poppius, was evaluated in an eggplant greenhouse, To study the biological control strategy of thrips. three Plots were established: Orius sauteri released plot without pesticide treatment (NRT), pesticide treated plot (PAT), and natural enemy removed plot (RNT) The nymphs of O. sauteri were found on the upper side of leaves in NRT at 21 days after the first release of O. sauteri. The density of thrips were dropped and maintained at lower level in NRT than in RNT. Average damage index of NRT, PAT and RNT was 1.35, 1.21 and 2.90 and the percentage of damaged fruit ratio of those was 70.3, 68.6 and 99.0%, respectively. The damage index and percentage of damaged fruit in NRT were slightly higher than those of PAT, but much lower than in RNT. Taylor's band Iwao's $\beta$ were greater than 1 for both populations. indicating aggregated distribution. Spatial coincidence index of O. sauteri was high most of the time even at low densities of both populations. The refuge index for thrips decreased as O. sauteri density increased. Results of this study suggest that O. sauteri is a promising natural enemy for thrips control on eggplant.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.3
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• pp.119-136
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• 2012

The goal of this study is to apply the IPCC(Intergovernmental Panel on Climate Change) concept of vulnerability to climate change and verify the use of a combination of vulnerability index and fuzzy logic to flood vulnerability analysis and mapping in Seoul using GIS. In order to achieve this goal, this study identified indicators influencing floods based on literature review. We include indicators of exposure to climate(daily max rainfall, days of 80mm over), sensitivity(slope, geological, average DEM, impermeability layer, topography and drainage), and adaptive capacity(retarding basin and green-infra). Also, this research used fuzzy model for aggregating indicators, and utilized frequency ratio to decide fuzzy membership values. Results show that the number of days of precipitation above 80mm, the distance from river and impervious surface have comparatively strong influence on flood damage. Furthermore, when precipitation is over 269mm, areas with scare flood mitigation capacities, industrial land use, elevation of 16~20m, within 50m distance from rivers are quite vulnerable to floods. Yeongdeungpo-gu, Yongsan-gu, Mapo-gu include comparatively large vulnerable areas. This study improved previous flood vulnerability assessment methodology by adopting fuzzy model. Also, vulnerability map provides meaningful information for decision makers regarding priority areas for implementing flood mitigation policies.