Bong-Ju Park

Polycyclic Aromatic Hydrocarbons in Soils and Crops After Irrigation of Wastewater Discharged from Domestic Sewage Treatment Plants

The effects of domestic wastewater application on the translocation and accumulation of polycyclic aromatic hydrocarbons (PAHs) in soil and crops (rice, lettuce, and barley) were investigated by Wagner’s pot experiment. In the soils and crops after domestic wastewater irrigation, high-molecular weight PAHs (5 to 6 ring) were not detected, but low-molecular weight PAHs (3 to 4 ring) were only detected at trace levels.

Comparison of Physicochemical Properties of Topsoil from Forest Development and Non-Development Area

Abstract This study was carried out to evaluate the physicochemical properties of topsoil from forest development area. The results of physicochemical properties of topsoil from forest development area shown on the average loamy sand~sandy clay loam in soil texture, 5.3~7.1 in pH, 0.02~0.18 dS/m in EC, 0.7~1.8% in OM, 0.03~0.11% in T-N, 11~15 cmol + /kg in CEC, 0.02~0.04 cmol + /kg in K + , 4.51~8.18 cmol + /kg in Ca 2+ , 0.93~2.77 cmol + /kg in Mg 2+ , 6~49 mg/kg in available phosphate. And the results of physicochemical properties of topsoil from forest non-development area shown on the average sandy loam~sandy clay loam in soil texture, 4.4~5.3 in pH, 0.03~0.05 dS/m in EC, 3.1~4.6% in OM, 0.13~0.23% in T-N, 14~18 cmol + /kg in CEC, 0.02~0.04 cmol + /kg in K + , 0.78~3.82 cmol + /kg in Ca 2+ , 0.29~1.31 cmol + /kg in Mg 2+ , 3~31 mg/kg in Av. P 2 O 5 . On the other hand, forest development area of topsoil sand content higher than 8~18% sand content than the forest non-development area. This trend is thought to be the absence of topsoil management development projects. Consequently, the results suggested a high potential of recycling of the topsoil from forest non-development area for planting soil. Therefore, in construction of the conservation and management of topsoil from forest non-development area is very important.

A Study on the Actual Condition of Topsoil Management at River Restoration Projects

This study aimed to research and analyze the real condition of topsoil management of river development field as a significant case among domestic development fields for topsoil preservation. Through survey with experts, we understood the real condition and problems of topsoil management during river development. In order to verify this, we analyzed the characteristics of soil before and after development focusing on the rivers recently completed as an ecological river restoration project, supervised by Ministry of Environment among domestic river improvement projects. The study results are like below. First, experts preferred collecting and reusing topsoil as the best method to maintain and improve soil for plant growth. Second, realistically collecting and reusing topsoil is not fully conducted due to economical issues and inconvenience in construction. In the soil condition, third, the contents of elements necessary for plant growth like organic matter and total nitrogen declined overall after development.

The Influence of Land Cover and Zoning on the Urban Heat Island in Cheongju

The present study observed temperature in order to identify factors affecting temperature by zoning and to measure the intensity of their impact on temperature. The empirical results of analyzing observed data are as follows. In order to make up for multicollinearity, a problem in multiple regression analysis, and to give more specific explanations, this study conducted factor analysis and obtained desirable data with adequacy and statistical significance. In the correlation matrix, factors decreasing temperature were planted areas, water surfaces and grasslands, and those increasing temperature were bare grounds, paved areas, and building area. According to land cover patterns, commercial areas had the highest temperature lowering effect. Through the rotated component matrix, we found that factors are grouped into those decreasing temperature, those increasing temperature, and those with low significance in increasing or decreasing temperature. In order to solve the problem of multicollinearity in multiple regression analysis, we performed factor analysis between the land use patterns and temperature and confirmed the usability of factor analysis as a new analysis method in urban heat island.

Physicochemical Properties of Topsoil Used for River Improvement and Non-Improvement Areas

This study was carried out to evaluate the physicochemical properties and perform a feasibility analysis of planting material composed of topsoil from river improvement and non-improvement areas. The results showed that the physicochemical properties of topsoil from river improvement areas were on the average sandy loam~loamy sand in soil texture, 5.6~6.8 in pH, 0.01~0.06 dS/m in EC, 0.9~2.1% in OM, 0.02~0.12% in T-N, 8~14 in CEC, 0.01~0.08 in Ex. , 2.55~11.11 in Ex. , 0.34~2.06 in Ex. , and 3~396 mg/kg in Av. . And non-improvement areas showed on average sandy clay loam~sand in soil texture, 5.7~6.7 in pH, 0.02~0.08 dS/m in EC, 0.9~4.4% in OM, 0.02~0.23% in T-N, 7~18 in CEC, 0.01~0.08 in Ex. , 3.81~12.67 in Ex. , 0.60~1.95 in Ex. , and 3~171 mg/kg in Av. . Meanwhile, the results of an applied valuation of topsoil- based planting were as follows. Ex. levels were low grade in all survey areas. OM was low grade in 12 improvement areas and 11 non-improvement areas. Av. levels were low grade in 10 improvement areas and 10 non-improvement areas. T-N was low grade in six improvement areas and four non-improvement areas. Ex. levels were low grade in two improvement areas.

Assessment of Temperature Reduction and Evapotranspiration of Green Roof Planted with Zoysia japonica

Abstract This was an experimental study to evaluate temperature reduction and evapotranspiration of extensive green roof. Three test cells with a dimension of 1.2(W)×1.2(D)×1.0(H) meters were built using 4-inch concrete blocks. Ten-centimeter concrete slab was installed on top of each cell. The first cell was control cell with no green roof installed. The second and third cells were covered with medium-leaf type Zoysiagrass ( Zoysia japonica ) above a layer of soil. Soil thickness on the second cell was 10cm and that on the third cell was 20cm. Air temperature, relative humidity and solar irradiance were measured using AWS (automatic weather system). Temperature on top surface and ceiling of the control cell and temperature on top surface, below soil and ceiling of green roof cells was measured. Evapotranspiration of the green roof cells were measured using weight changes. Compared with temperature difference on the control cell, temperature difference was greater on green roof cells. Between two green roof cells, the temperature difference was greater on the third cell with a thicker soil layer. Temperature differences below soil and on ceilings of green roof cells were found greater than those of the control cell. Between the green roof cells, there was no difference in the temperature reduction effects below soil and on ceilings based on substrate depth. In summary, green roof was found effective in temperature reduction due to evapotranspiration and shading effect.

Density and Species Composition of Soil Seed Bank in Rural Stream Topsoil

Purpose of this study was to evaluate germination characteristics of soil seed bank in rural stream topsoil using seedling emergence method in order to provide data for future ecological restoration of stream utilizing topsoil. There were 24 families, 52 genera, 61 taxa of soil seed bank flora found in topsoil from 6 rural streams. The most frequently found taxa were Compositae (12 taxa) followed by Gramineae (8 taxa), Caryophyllaceae (5 taxa), Cruciferae (4 taxa), Scrophulariaceae, Labiatae, Polygonaceae and Cyperaceae. Plant with the most number of germination was Stellaria aquatica followed by Erigeron annuus, Imperata cylindrica var. koenigii, Poa annua, Cyperus microiria and Veronica undulata. Naturalized plants found were Erigeron annuus, Rumex crispus, Oenothera odorata, Cerastium glomeratum, Bidens frondosa, Erigeron philadelphicus, etc.