• Ecology and Resilient Infrastructure
• /
• v.7 no.4
• /
• pp.227-237
• /
• 2020

Microclimatic data were measured, and the human thermal sensation was analyzed at 10 local climate zones based on the major land cover classification to investigate the thermal environment of urban areas during summer nighttime. From the results, the green infrastructure areas (GNIAs) showed an average air temperature of 1.6℃ and up to 2.4℃ lower air temperature than the gray infrastructure areas (GYIAs), and the GNIAs showed an average relative humidity of 9.0% and up to 15.0% higher relative humidity. The wind speed of the GNIAs and GYIAs had minimal difference and showed no significance at all locations, except for the forest location, which had the lowest wind speed owing to the influence of trees. The local winds and the surface roughness, which was determined based on the heights of buildings and trees, appeared to be the main factors that influenced wind speed. At the mean radiant temperature, the forest location showed the maximum value, owing to the influence of trees. Except at the forest location, the GNIAs showed an average decrease of 5.5℃ compared to GYIAs. The main factor that influenced the mean radiant temperature was the sky view factor. In the analysis of the human thermal sensation, the GNIAs showed a "neutral" thermal perception level that was neither hot nor cold, and the GYIAs showed a "slightly warm" level, which was a level higher than those of the GNIAs. The GNIAs showed a 3.2℃ decrease compared to the GYIAs, except at the highest forest location, which indicated a half-level improvement in the human thermal environment.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.50 no.2
• /
• pp.1-22
• /
• 2022

The modification effects of street trees on outdoor thermal comfort in summertime according to tree planting types and road direction were analyzed using a computer simulation program, ENVI-met. With trees, the air temperature and wind speed decreased, and the relative humidity increased. In the case of mean radiant temperature (T_mrt) and human thermal sensation, physiological equivalent temperature (PET) and universal thermal climate index (UTCI), there was a decrease during the daytime. The greatest change among the meteorological factors by trees happened in Tmrt, and PET and UTCI showed similar patterns with T_mrt·The most effective tree planting type on thermal comfort modification was low tree height, wide tree crown, high leaf area index, and narrow planting interval (LWDN). T_mrt, PET and UTCI showed a large difference depending on shadow patterns of buildings and trees according to solar altitude and azimuth angles, and building locations. When the building shade areas increased, the thermal modification effect by trees decreased. In particular, results on the east and west sidewalks showed a large deviation over time. When applying the LWDN, the northwest, west and southwest sidewalks showed a significant reduction of 8.6-12.3℃ PET and 4.2-4.5℃ UTCI at 10:00, and the northeast, east and southeast sidewalks showed 8.1-11.8℃ PET and 4.4-5.0℃ UTCI at 16:00. On the other hand, when the least effective type (high tree height, narrow tree crown, low leaf area index, and wide planting interval) was applied, the maximum reduction was up to 1.8℃ PET and 0.9℃ UTCI on the eastern sidewalks, and up to 3.0℃ PET and 0.9℃ UTCI on the western ones. In addition, the difference in modification effects on T_mrt, PET and UTCI between the tree planting types was not significant when the tree effects were reduced by the effects of buildings. These results can be used as basic data to make the most appropriate street tree planting model for thermal comfort improvement in urban areas in summer.

• Journal of Agricultural Extension & Community Development
• /
• v.7 no.1
• /
• pp.155-166
• /
• 2000

When the marcher visited Korea in fall 1994, he was shocked to see high rise apartment buildings around the capitol region including Seoul and Suwon, resulting from rising demand of housing because of urban migration followed by second and third industrial development. After 6 years in March 2000, the researcher witnessed more apartment buildings and vinyl house complexes, one of the evidences of continued economic progress in Korea. Korea had to receive the rescue finance from International Monetary Fund (IMF) because of financial crisis in 1997. However, the sign of recovery was seen in a year, and the growth rate of Gross Domestic Products (GDP) in 1999 recorded as high as 10.7 percent. During this period, the Korean government has been working on restructuring of banks, enterprises, labour and public sectors. The major directions of government were; localization, reducing administrative manpower, limiting agricultural budgets, privatization of public enterprises, integration of agricultural organization, and easing of various regulations. Thus, the power of central government shifted to local government resulting in a power increase for city mayors and county chiefs. Agricultural extension services was one of targets of government restructuring, transferred to local governments from central government. At the same time, the number of extension offices was reduced by 64 percent, extension personnel reduced by 24 percent, and extension budgets reduced. During the process of restructuring, the basic direction of extension services was set by central Rural Development Administration Personnel management, technology development and supports were transferred to provincial Rural Development Administrations, and operational responsibilities transferred to city/county governments. Agricultural extension services at the local levels changed the name to Agricultural Technology Extension Center, established under jurisdiction of city mayor or county chief. The function of technology development works were added, at the same time reducing the number of educators for agriculture and rural life. As a result of observations of rural areas and agricultural extension services at various levels, functional responsibilities of extension were not well recognized throughout the central, provincial, and local levels. Central agricultural extension services should be more concerned about effective rural development by monitoring provincial and local level extension activities more throughly. At county level extension services, it may be desirable to add a research function to reflect local agricultural technological needs. Sometimes, adding administrative tasks for extension educators may be helpful far farmers. However, tasks such as inspection and investigation should be avoided, since it may hinder the effectiveness of extension educational activities. It appeared that major contents of the agricultural extension service in Korea were focused on saving agricultural materials, developing new agricultural technology, enhancing agricultural export, increasing production and establishing market oriented farming. However these kinds of efforts may lead to non-sustainable agriculture. It would be better to put more emphasis on sustainable agriculture in the future. Agricultural extension methods in Korea may be better classified into two approaches or functions; consultation function for advanced farmers and technology transfer or educational function for small farmers. Advanced farmers were more interested in technology and management information, while small farmers were more concerned about information for farm management directions and timely diffusion of agricultural technology information. Agricultural extension service should put more emphasis on small farmer groups and active participation of farmers in these groups. Providing information and moderate advice in selecting alternatives should be the major activities for consultation for advanced farmers, while problem solving processes may be the major educational function for small farmers. Systems such as internet and e-mail should be utilized for functions of information exchange. These activities may not be an easy task for decreased numbers of extension educators along with increased administrative tasks. It may be difficult to practice a one-to-one approach However group guidance may improve the task to a certain degree.

• Korean Journal of Plant Resources
• /
• v.29 no.4
• /
• pp.495-503
• /
• 2016

In the present study, we investigated the plant growth characteristics and biological activity of four asparagus cultivars grown using two cultural methods and tested the possibility of domestic open field. The number of shoots, buds, roots, shoot and root fresh and dry weights, and total dry weight of the four asparagus cultivars grown in a plastic house were higher than those of the same cultivars grown in an open field. Of the cultivars grown in the open field, Jersey Giant had greater shoot number than the other cultivars. In plastic house cultivation, the number of buds in Jersey Supreme was greater than the other cultivars. The total flavonoid content of the Jersey Giant was greater than the other cultivars, but cultural method was unaffected. The total polyphenol contents in asparagus cultivars grown in the plastic house were higher than those of cultivars grown in the open field. The total polyphenol content of the Jersey Giant grown the plastic house was significantly higher than those of other cultivars. Antioxidant activity such as catalase (CAT) and peroxidase (POX) did not differ significantly with cultural methods and among the cultivars. Ascorbate peroxidase (APX) activity of asparagus cultivars grown in the open field was higher than that of cultivars grown in the greenhouse; the highest APX activity was detected in UC157. Thus, greenhouse cultivation is expected to improve plant growth characteristics and biological activities of asparagus cultivars; each cultural method should be considered when selecting a suitable cultivar for high yield and high bioactive compound content.

• Korean Journal of Environmental Agriculture
• /
• v.32 no.1
• /
• pp.24-34
• /
• 2013

BACKGROUND: This study was carried out to compare population size of mudfish (Misgurnus mizolepis) between the agricultural practices and to investigate the causes of its differences. We also provided basic information for sustainable use of mudfish population in paddy fields. METHODS AND RESULTS: Mudfish and benthic invertebrates which are diet of mudifish were investigated from 8 sites of organic and conventional rice paddy fields in South Korea. Total number of mudfish were 1,882 individuals in survey sites. Mudfish population were 2.4 times larger in organic paddy fields (1,333 individuals) than in conventional paddy fields (549 individuals). The population size of mudfish was larger in Mungyeong-si, Gyeongsangbuk-do and Anseong-si, Gyeonggi-do with relatively better environmental conditions than the other 5 sites including Suwon-si, Gyeonggi-do, Cheongyang-gun, Chungcheongnam-do, Gunsan-si, Jeollabuk-do, Gimje-si, Jeollabuk-do, Hwasun-gun, Jeollanam-do, Hamyang-gun, Gyeongsangnam-do. Benthic invertebrates collected from survey sites were 74 species, 68 genera, 46 families, 19 orders, 6 classes and 3 phyla. According to agricultural practices, benthic invertebrates were identified 66 species, 62 genera, 41 families, 17 orders, 6 classes and 3 phyla in organic paddy fields while there were 66 species, 60 genera, 42 families, 18 orders, 6 classes and 3 phyla in conventional paddy fields. Dominant invertebrates were Chironomidae sp., Branchiopoda sp., Ostracoda sp., and Copepoda sp. There were no differences in dominant species between organic and conventional paddy fields. Population size of mudfish tended to increase with the population size of Chironomidae sp., Branchiopoda sp., Ostracoda sp., and Copepoda sp. But, only population of Chironomidae sp. and Copepoda sp. statistically related to population size of mudfish. The number of individuals of mudfish (Misgurnus mizolepis) was higher at the low rate of urban area than any other surveyed region and was affected by appearance ratio of main preys such as Chironomidae sp. and Ostracoda sp. CONCLUSION(S): The population size of mudfish in rice paddy fields could be affected by environmental conditions and agricultural practices such as organic and conventional methods.

• Korean Journal of Environmental Agriculture
• /
• v.25 no.1
• /
• pp.77-84
• /
• 2006

This study was conducted to find a system for screening organic resources with 16 species, 62 samples which were selected to randomizing point from city, province and industrial areas in the whole country. Content of organic matters were $65.3%{\sim}98.0%$ in all samples so that they were largely over than 60%, raw material regulation of compost. Concentrations of total nitrogen and total phosphorus were $0.7{\sim}4.8%\;and\;0.8{\sim}5.0$, they could look for effect of the nitrogen and phosphorus supply as a raw material of compost. In case of 8 elements concentrations of heavy metal, they were too high to use as raw materials of compost which were over to regulation limit in Cu, Cr, Ni, and As from fiber industry, Ni from food company and leather industry, and the others are adapt to limit levels. HEM contents fro the highest to $113mg\;kg^{-1}$ from liber industry and PAHs content were the highest to $3,462ug\;kg^{-1}$ from paper-mill manufacture. Distribution of PAHs concentiations were naphthalene>phenanthrene>pyrene>fluoroanthene>acenaphthene. $Microtox{(R)}\;EC_{50}$ values for bioassay were pharmaceutical company>paper-mill manufacture>industrial area sewage sludge>fiber industry>urban sewage sludge>metropolitan sewage sludge. HEM between Zn, Cu, and Ni was significant at the 99% and between Cd was significant at the 95%, Microtox between Hg and BEM significant at the 95%.

• Journal of Korean Society of Forest Science
• /
• v.87 no.3
• /
• pp.404-414
• /
• 1998

The purpose of this study was to investigate the influence of air pollution using epiphytic lichens on forest trees around Ulsan and Onsan industrial complex from April to June, 1997. The distribution of lichens was investigated at 58 sampled sites. In this study, 16 kinds of epiphytic lichens were recorded, of them, Lepraria sp. having a tolerance to air pollution showed the highest frequency as 30.85%, and in order of Lecanora strobilina(26.18%) and Parmelia austrosinensis(13.42%) unknown to tolerance of air pollution. The number of lichens was gradually decreased around industrial complex, where so - called "lichen desert" was detected. As being distant from the industrial complex, the mean degrees of cover were increased. The degrees of cover in the investigated sites ranged from I to V. According to $SO_2$ concentration limiting lichen's growth, the pattern of distribution of Cladonia sp., Dirinaria applanata, Parmelia austrosinensis, Lepraia sp. and Lecanora strobilina were dissimilar by sensitivity to air pollution Especially Lepraria sp. and Lecanora strobilina were widely distributed to degree of cover from I to V, and as the both had a similar distribution pattern, it could be inferred that Lecanora strobilina had also a tolerance to air pollution. The IAP values ranging from 0 to 64.3 were arranged into six groups and the investigated area was delineated into six IAP zones to represent degree of air environment. It was a high IAP value as being distant from industrial complex. The mare IAP increased, the more number of kinds of lichens increased. It was confirmed that the number of species, coverage and IAP value of epiphytic lichens showed a tendency to decrease of urban area and industrial complex.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.44 no.4
• /
• pp.100-108
• /
• 2016

The climatic index for tourism(CIT) has recently been advanced, which includes complete human energy balance models such as physiological equivalent temperature(PET) and universal thermal climate index(UTCI). This study investigated human thermal sensation and comfort at Woljung-ri Beach, Jeju, Republic of Korea, in spring and summer 2015 for landscape planning and design in beach areas. Microclimatic data measurements and human thermal sensation/comfort surveys from ISO 10551 were conducted together. There were 869 adults that participated. As a result, perceptual and thermal preference that consider only physiological aspects had high coefficients of determination($r^2$) with PET in linear regression analyses: 92.8% and 87.6%, respectively. However, affective evaluation, personal acceptability and personal tolerance, which consider both physiological and psychological aspects, had low $r^2s$: 60.0%, 21.1% and 46.4%, respectively. However, the correlations between them and PET were all significant at the 0.01 level. The neutral PET range in perceptual for human thermal sensation was $25{\sim}27^{\circ}C$, but a PET range less or equal to 20% dissatisfaction, which was recommended by ASHRAE Standard 55, could not be achieved in perceptual. Only PET ranges in affective evaluation and personal tolerance affected by both aspects were qualified for the recommendation as $21{\sim}32^{\circ}C$ and $17{\sim}37^{\circ}C$, respectively. Therefore, the PET range of $21{\sim}32^{\circ}C$ is recommended to be used for the human thermal comfort zone of beach areas in landscape planning and design as well as tourism and recreational planning. PET heat stress level ranges on the beach were $2{\sim}5^{\circ}C$ higher than those in inland urban areas of the Republic of Korea. Also, they were similar to high results of tropical areas such as Taiwan and Nigeria, and higher than those of western and middle Europe and Tel Aviv, Israel.

• Journal of agriculture & life science
• /
• v.46 no.3
• /
• pp.1-10
• /
• 2012

This study was carried out to provide basal information on factors effected the decline of Pinus thunbergii by analysisof, the content of chlorophyll, and acid deposition through stepwise regression analysis. pH in throughfall at industrial area was 4.65 in the spring and 4.72 in the fall. On the contrary, pH at rural area was measured 5.32 in the spring and 5.34 in the fall. EC of rain fall at industrial area was $262.30{\mu}s$, However, there was $47.72{\mu}s$ at control area. Of anions, the concentration of ${NO_3}^-$ was $52.13mg/{\ell}$ at industrial area and $37.85mg/{\ell}$ at area. The concentration of ${SO_4}^{2-}$ was $57.89mg/{\ell}$ at industrial area and $36.21mg/{\ell}$ at area. Of the concentration of leaf chlorophyll in Pinus thunbergii, chlorophyll a was 0.2378 but control area was 0.4378. Also the content of chlorphyll b was 0.2097 and control area was 0.2345. The degree of decline of Pinus thunbergii forest was 2.97 at industrial area and 1.20 at area. We carried out a correlation analysis between the degree of decline and the concentration of ions, $SO_2$, and $NO_2$ in Pinus thunbergii forest. As a result, there was a negative correlation (r=-0.8672) between rain acids, and a positive correlation between $SO_2$ concentrations (r=0.8924) and between $NO_2$ concentrations (r=0.8428) in air. The correlations among acid depositions at level of 1% were pH (r=-0.8672), ${NO_3}^-$(r=0.6996), ${SO_4}^{2-}$(r=0.8497), $SO_2$ (r=0.8924), and $NO_2$ (r=0.8428).

• Journal of the Korean Institute of Landscape Architecture
• /
• v.50 no.1
• /
• pp.68-77
• /
• 2022

The human thermal environment in an apartment complex located in Seoul was quantitatively analyzed to devise methods to modify human heat-related stresses in landscape and urban planning. Microclimatic data (air temperature, relative humidity, wind speed, and short- and long-wave radiation) were collected at 6 locations [Apt-center, roof (cement), roof (grass), ground, playground, and a tree-lined road] in the late spring and summer, and the data were used to estimate the human thermal sensation, physiological equivalent temperature (PET) and universal thermal climate index (UTCI). As a result, the playground location had the highest thermal environment, and the roof (grass) location had the lowest. The mean difference between the two locations was 0.8-1.1℃ in air temperature, 1.8-4.0% in relative humidity, and 7.5-8.0℃ in mean radiant temperature. In open space locations, the wind speed was 0.4-0.5 ms-1 higher than others. Also, a wind tunnel effect happened at the Apt-center location during the afternoon. For the human thermal sensation, PET and UTCI, the mean differences between the playground and roof (grass) locations were: 5.2℃ (Max. 11.7℃) in late spring and 5.4℃ (Max. 18.1℃) in summer in PET; and 3.0℃ (Max. 6.1℃) in late spring and 2.6℃ (Max. 9.8℃) in summer in UTCI. The mean differences indicated a level change in PET and 1/2 level in UTCI, and the maximum differences showed greater changes, 2-3 levels in PET, and 1-1.5 levels in UTCI. Moreover, the roof (grass) location gave 4.6℃ PET reduction and a 2.5℃ UTCI reduction in late spring, and a 4.4℃ PET reduction and a 2.0℃ UTCI reduction in the summer when compared with the roof (cement) location, which results in a 2/3 level change in PET and a 1/3 level in UTCI. Green infrastructure locations [roof (grass), ground, and a tree-lined road] were not statistically significant in the reduction of PET and UTCI in thermal environment modifying effects. The implementation of green infrastructure, such as rooftop gardens, grass pavement, and street tree planting, should be adopted in landscape planning and be employed for human thermal environment modification.