• Journal of Environmental Science International
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• v.3 no.1
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• pp.31-38
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• 1994

The diffusion of the pollutants released into atmosphere is dependent on its chemical reaction, topography and micrometeorological characteristics. The purpose of the study is to investigate how much micrometeorological characteristics such as stability, wind speed and mixing height affect the diffusion of the air pollutants. For this purpose, this paper let 1) the basic theory be K-theory, 2) eddy diffusivity and wind speed be dependent on mixing height and stability, and 3) Grout method be used for numeric calculation. The result was 1) the more unstable condition, the higher mixing height and the higher wind speed we, the lower pollutants concentration appears, 2) the most intensive effect on the distribution of the pollutant concentration is the atmospheric stability.

• ALGAE
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• v.18 no.2
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• pp.169-176
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• 2003

Algal growth potential test (AGPT) bioassay were conducted to evaluate the stream and reservoir water in the Okchon Stream Watershed during May to September 2002. The water quality of the stream water was clean in the upstream, deteriorating toward the downstream. In particular, SRP and $NH_4$ significantly increased due to treated wastewater. The average AGPT value of the Okchon Stream watershed was 22.4 mg dw ${\cdot}l^{-1}$, with the range of 0- 195.7 mg dw ${\cdot}l^{-1}$. AGPT value was the highest immediately after inflow of treated wastewater, averaging 91.3 mg dw${\cdot}l^{-1}$. AGPT was highly correlated with SRP, $NH_4$ and TIN factors, with P having the greatest effect on the growth of algae. Among N components, $NH_4$ was preferred to $NO_3$ for the growth of algae. Likewise, AGPT was closely linked to meteological and hydrological effects and development of natural phytoplankton. In survey stations, mesotrophic, eutrophic and hypertrophic conditions accounted for 43%, 21% and 36%, respectively. On the other hand, hypertrophic condition focused on the downstream reaches. AGPT was useful in determining not only the limiting nutrients but also the water fertility for the growth of algae. Based on the AGPT results, the management of point sources for water pollution in treated wastewater was important in the protection of aquatic environment in the stream and embayment.

• Journal of Korean Society of Rural Planning
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• v.8 no.1 s.15
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• pp.3-14
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• 2002

Changes of chemical properties by times of the reclaimed tidal land soils and soil surface water, underground infiltration water with precipitation-runoff on natural meteological condition in the unripened tidal reclaimed paddy fields were investigated. This study was carried out to use environment-friendly farm land in the reclaimed tidal lands. The soils used in this study were saline-alkaline soils with the high $Na^+$ and $Mg^{++}$ content. As the results of investigation outflow loading of nutriments through outflow water in the unripened tidal reclaimed paddy fields by precipitation during the survey period, nutriments equivalent to T-N $1{\sim}2\;kg\;10a^{ -1}$ and T-P $0.01{\sim}0.02\;kg\;10a^{-1}$ from in the unripened tidal lands were discharged. Besides, the results of comparison losses of cation through outflow water showed $Na^+>\;K^+>\;Mg^{++}\;>\;Ca^{++}$, and the highest appeared water discharge of $Na^+$. In case of saemangeum reclaimed tidal land soils water discharge of cations showed $Ca^{++}$ 1.3 kg $10a^{-1}$, $Mg^{++}$ 1.6 kg $10a^{-1}$, $Na^+$ 17.7 kg $10a^{-1}$, and $K^+$ 3.2 kg $10a^{-1}$ respectively. On the other hand, in case of koheung reclaimed tidal lands soils water discharge of cations showed $Ca^{++}$ 18.1 kg $10a^{-1}$, $Mg^{++}$ 31.2 kg $10a^{-1}$, $Na^+$ 320.8 kg $10a^{-1}$ and $K^+$ 51.2 kg $10a^{-1}$ respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.177-183
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• 2008

Sodium is known to reduce a plant growth and yields. However, the relationships between physiological response of seedling and salinity stress caused by growing media are not well understood yet. We conducted experiments to investigate change of some parameters including Na, EC, moisture content in media under different air temperature ($15^{\circ}C$, $25^{\circ}C$), and the response of fruit-vegetables such as cucumber, oriental melon on saline conditions originated from horticultural substrate. Volumetric moisture content of media at $15^{\circ}C$ was 70%, but at $25^{\circ}C$ was decreased by 45% within 22 hrs, showing below optimal matric potential, approximately. During reaction time, the increase of Na concentration was significantly greater in saline substrate than in control. The decrease rate of Na concentration according to supplying irrigation water was higher in saline substrate than in control. $CO_2$ assimilation rate and transpiration rate of Korea melon grown in low temperature were decreased with a Na/cation ratio in hydroponic solution. Water saturation deficit was also increased significantly at $15^{\circ}C$ as compare to $25^{\circ}C$. Saline stress during nursery stage induced a reduction of seedling quality, growth and cucumber yield. The results suggest that the relationship between uncontrolled Na uptake of seedling from saline substrate and meteological condition is responsible for saline stress.