• Journal of Korea Water Resources Association
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• v.40 no.2 s.175
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• pp.183-190
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• 2007

Soil layer in vegetation filter strip is one of the very important factor for reduction of non-point pollutants by physical, chemical and biological reactions of it through infiltration process. This study was carried out to prepare more effective vegetation filter strip through modification of soil layer for river water quality improvement. Therefore, the main aims of this study are to compare and evaluate normal (straighten type) and modified (step type) vegetation filter strip, which make artificially change the soil layer to improve infiltration ability, through bench scale experiments. In the results of this study, vegetation filter strip of step type is much more highly reduction effectiveness of pollutants in surface flow compared with normal vegetation filter strip. In case of below effluent, however, it appeared that the vegetation filter strip modified soil layer showed lower reduction effectiveness of pollutants than the general vegetation filter strip. This result was judged because effluent through the vegetation filter strip of step type passed bigger size of aggregate or sand than the vegetation filter strip of straighten type. If we compare it as a definition of pollutant load to estimate total amount of reduced pollutants by vegetation filter strip, reduced pollutants load by step type showed higher than those by straighten type because below effluent amount relied on total effluent amount was higher at step type (4%) than at straighten type (2%). In conclusion, the vegetation filter strip of step type to improve infiltration effect is much more reduction effectiveness of pollutants than vegetation filter strip of straighten type.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.472-472
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• 2004

Numerous studies on urban groundwater have been carried out in many other countries. Urban groundwater shows a unique hydrologic system because of complex urban characteristics such as road pavement, sewers and public water supply systems. These urban facilities may change the characteristics of groundwater recharge but contaminate its quality as well. There have been several researches on urban groundwater in Seoul. Seoul has been industrialized very rapidly so that the city has large population. The recent population in Seoul amounts to more than ten millions, corresponding to a very high density of about 17, 000 people/km$^2$. Therefore, many factors affect the groundwater quality and quantity in Seoul. Nowadays, groundwater in Seoul is being extracted for construction, industrial use, and drinking and so on. There are 15, 714 wells in Seoul and its annual usage is 41, 425, 977m$^3$(in 2001). Therefore, systematic studies are needed to properly manage and use the groundwater in Seoul. The purposes of this study in progress are to identify geochemical characteristics of groundwater in Seoul and to determine the extent of groundwater contamination and its relationship with urban characteristics. For this study, groundwater was sampled from more than 400 preexisting wells that were randomly selected throughout the Seoul area. For all samples, major cations together with Si, Al, Fe, Pb, Hg For 200 samples among them, TCE, PCE, BTEX were also analyzed by GC. Our study shows that groundwater types of Seoul are distributed broadly from Ca-HCO$_3$ type to Ca-Cl＋NO$_3$ type. The latter type indicates anthropogenic contamination. Among cations, Ca is generally high in most samples. In some samples, Na and K are dominant. The dominant anions change widely from HCO$_3$ to Cl＋NO$_3$. The anion composition is considered to effectively indicate the contribution of distinct anthropogenic sources. In addition, major ions are positively proportional to total dissolved solid (TDS) except K and NO$_3$. Thus, we consider that TDS may be used as an effective indicator of the extent of pollution. However, the increase of TDS may result from increased water-rock interaction. To determine the extent of groundwater contamination, it is needed to figure out the baseline water quality in Seoul. Furthermore, detailed geochemical studies are required to find out pollution sources and their corresponding hydrochemical parameters.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.90-95
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• 2010

The application of livestock manure to cropland is a practice that has been used for centuries. Agricultural crops can utilize nutrients from manure, and the producer can utilize land for disposal, although in a "sustainable system" the concept is manure utilization and not waste disposal. However, meeting regulatory criteria regarding microbial quality remains an expensive and time consuming process. The purpose of this study was to quantify the level of environmental impact of soil moisture and temperature on fecal coliform (Escherichia coli or E. coli) survival in upland soils for sound application of livestock manure. Samples were collected up to 30 days depending on the given conditions. The inactivation rate of E. coli increased linearly with increased temperature while the inactivation rate gradually decreased with decreased soil moisture level. The overall findings of this study showed that the temperature was the limited factor on E. coli survival in soils over soil moisture content. This study will provide useful and practical guidelines to applicators of soil in deciding appropriate handling and time frames for land application for sustainable agriculture.

• Economic and Environmental Geology
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• v.41 no.3
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• pp.327-334
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• 2008

Understanding the chemical characteristics of sediments and the nutrient diffusion from sediments to the water body is important in the management of surface water quality. Changes in chemical properties and nutrient concentration of a submerged soil were monitored for 6 months using a microcosm with the thickness of 30cm for upland soil and 15cm of water thickness above the soil. The soil color changed from yellowish red to grey and an oxygenated layer was formed on the soil surface after 5 week flooding. The redox potential and the pH of the pore water in the microcosm decreased during the flooding. The nitrate concentration of the surface water was continuously increased up to $8\;mg\;l^{-1}$ but its phosphate concentration decreased from $2\;mg\;l^{-1}$ to $0.1\;mg\;l^{-1}$ during flooding. However, the concentrations of $NH_4^+$, $PO_4^{3-}$, Fe and Mn in the pore water were increased by the flooding during this period. The increased $NO_3^-$ in the surface water was due to the migration of $NH_4^+$ formed in the soil column and the oxidation to $NO_3^-$ in the surface water. The increased phosphate concentration in the pore water was due to the reductive dissolution of Fe-oxide and Mn-oxide, which scavenged phosphate from the soil solution. The oxygenated layer played a role blocking the migration of phosphate from the pore water to the water body.

• Journal of Soil and Groundwater Environment
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• v.18 no.1
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• pp.123-128
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• 2013

Water quality and contamination of sediment is a growing concern in the Iksan stream of Korea. Heavy metal contamination and changes in the physicochemical properties of the stream were evaluated. Water and sediment samples were collected from six sites during the dry and rainy seasons; pH, DO, EC, ORP, turbidity, $PO_4$-P, $NO_3$-N and selected heavy metals (Cu, Pb, Ni, As, Zn, Cd, Hg) were measured. Results showed almost no change in pH between seasons. DO was highest at site 2 (~2.63 mg/L) in the dry season; EC (1,540 ms/m) was greatest at site 1 in both seasons. The ORP gradually increased from the dry to rainy season at most of the sites and was highest at site 5. Turbidity was highest at site 1 and gradually decreased from the dry to rainy season at all sites except site 3. $PO_4$-P ranged from a high of 1,193mg/L at site 1 to in the dry season to a low of ~1.2 mg/L at site 4. In contrast, $NO_3$-N was highest at site 3 in the rainy season (12,531 mg/L). Among the heavy metals measured, Cu and Zn concentrations were highest at all sediment sites. Cu and Zn are added to livestock feed to improve reproductive rates and can be carried to the stream with manure. Transport of sediment and heavy metals during the rainy season is the major source of stream contamination and it is important to continue monitoring and take necessary action in these areas.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.471-478
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• 2018

The purpose of this study was to investigate effects of reusable organic wastes, on soil organisms and chemical properties. Bone meal, de-oiled cake, and oyster shell were applied and abundances of soil organisms were measured at 3 and 15 months, after treatment in soil under sawleaf zelkova cultivation. Soil organisms are affected, by the quality of applied organic wastes. Abundance of microorganisms was higher in oyster shell treated soils than in untreated soils, suggesting that soil pH is a driving force, altering abundance and structure of the microbial community. Increase in abundance of bacterivorous nematodes was observed under treatment with bone meal and de-oiled cake, but there was slight change in abundance of fungivorous and herbivorous nematodes. Abundance of herbivorous nematode was positively correlated with plant growth, at 15 months after treatment. Response of microarthropods in the Collembola and Oribatida was not apparent. Abundances of primary consumers were not significantly correlated with microorganisms. This study suggested that organic waste influences soil organisms primarily by altering soil chemical properties and bottom-up effects may not occur in trophic reactions.

• Journal of the Korean GEO-environmental Society
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• v.14 no.10
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• pp.29-37
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• 2013

In this study, we constructed the test embankment with four kinds of sections(2 kinds of bottom ash; tire shred-bottom ash mixture, weathered soil) in field and had been monitoring the behaviour of the test embankment and change of ground water quality for 1 year. In the geotechnical aspects, there was no relative difference of deformation in 4 test materials section and we could not see the possibility of the strength-reduction of coal ash materials by freezing inside of the embankment. In addition, no settlement was observed in the test sections because the base soil of the test sections was rigid enough that no consolidation was occurred. In the examination of water quality, all of the heavy metals and negative ions were detected below the drinking water standards except for sulfate($SO_4^{2-}$). In the beginning of measurement, higher concentrations of sulfate from 4 test sections were detected than drinking water standard for 20 days after beginning of the test but the concentrations decreased below the drinking water standard after 50 days after the tests.

• Journal of Soil and Groundwater Environment
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• v.17 no.3
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• pp.39-48
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• 2012

Visual MODFLOW, a three dimensional groundwater flow model, was used to analyze effects of a weir construction in an alluvial stream on the nearby groundwater flow system. A hypothetical conceptual model was developed to investigate how the groundwater level and the water budget could change after a weir construction depending on the location of tributary streams. A site example, dealing with the Juksan weir installed in the Yeongsan River, was also demonstrated to predict the effects of the weir construction. Model results show that impacts of a weir construction on the groundwater flow system greatly vary depending on how far a tributary is located and whether it is located downstream or upstream from the weir. Therefore, consideration of the location of tributaries in planning the location of a weir could effectively minimize the impacts of a weir construction on the groundwater flow system. It is also demonstrated that model results are highly dependent upon how the model is dealing with small tributaries and agricultural drainage channels, which can be easily found nearby the main streams, acting as major water bodies for groundwater discharge. The model for the Juksan area shows that the weir construction will change the direction of groundwater flow in some areas, leading to changes of groundwater quality and interaction of the Yeongsan River to the aquifer from a gaining to a losing stream. The model also predicted the areas where rise of groundwater level caused by the Juksan weir could adversely affect plant growth, and thereby suggested installing new drainage channels as a countermeasure to drawdown the groundwater level.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.769-779
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• 2019

Chilli peppers are predominantly cultivated in open field systems under abiotic and biotic stress conditions. Abiotic and biotic factors have a considerable effect on plant performance, fruit quantity, and quality. Chilli peppers grow well in a tropical climate due to their adaptation to warm and humid regions with temperatures ranging from 18 to 30℃. Nowadays, chilli peppers are cultivated all around the world under different climatic conditions, and their production is gradually expanding. Expected climate changes will likely cause huge and complex ecological consequences; high temperature, heavy rainfall, and drought have adverse effects on the vegetative and generative development of all agricultural crops including chilli peppers. To gain better insight into the effect of climate change, the growth, photosynthetic traits, morphological and physiological characteristics, yield, and fruit parameters of chilli peppers need to be studied under simulated climate change conditions. Moreover, it is important to develop alternative agrotechnologies to maintain the sustainability of pepper production. There are many conceivable ideas and concepts to sustain crop production under the extreme conditions of future climate change scenarios. Therefore, this review provides an overview of the adverse impacts of climate change and discusses how to find the best solutions to obtain a stable chilli pepper yield.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1027-1034
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• 2011

In order to provide the basic information on the agricultural environment in Daegwallyeong Highland, the characters of weather, water, and soil quality were investigated. The meteorological characteristics was monitored by automatic weather system (AWS) at 17 sites. The quality of water for samples were collected monthly at 24 sites depending on landuse style. Soil samples were collected from a forest, grassland, and the major vegetable cultivation areas such as potato, carrot, Chinese cabbage, onion, head lettuce, and welsh onion field. The weather showed the mountain climate, and the average yearly temperature is $6.4^{\circ}C$, the average temperature in January is $-7.6^{\circ}C$ and the average temperature in July is $19.1^{\circ}C$, and the change of temperature on the districts of Daegwallyeong is severe. The yearly record of precipitation shows 1717.2 mm. The water quality of crop field was worse than forest or grassland in Daewallyeong highland. In 2005, annual T-N, T-P, SS distribution of Chinese cabbage field showed 7.4~11.3, 0.061~0.1, and $3.0{\sim}53.0mg\;L^{-1}$. The potato field showed 3.1~7.2, 0.019~0.056 and $0.5{\sim}3.0mg\;L^{-1}$, respectively. Being compared of water quality between potato field and chinese cabbage field, it showed that the water quality of Chinese cabbage field was worse than potato field. On farming, the soil of crop cultivation showed pH 5.6 to 6.8, $18.0{\sim}42.4g\;kg^{-1}$ of OM, $316{\sim}658mg\;kg^{-1}$ of Avail. $P_2O_5$. The content of cations showed $0.41{\sim}0.88cmol_c\;kg^{-1}$ of Exch. K, $3.73{\sim}7.07cmol_c\;kg^{-1}$ of Exch. Ca and $1.17{\sim}1.90cmol_c\;kg^{-1}$ of Exch. Mg.