• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.218-224
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• 1998

The coefficients of variation obtained from three typical vegetation indices of eight levels of multi-spatial resolution images in urban areas were employed to identify the optimum spatial resolution in terms of maintaining information quality. These multi-spatial resolution images were prepared by degrading 1 meter simulated, 16 meter ADEOS/AVNIR, and 30 meter Landsat-TM images. Normalized Difference Vegetation Index (NDVI), Perpendicular Vegetation Index (PVI) and Soil Adjusted Ratio Vegetation Index (SARVI) were applied to reduce data redundancy and compare the characteristics of multi-spatial resolution image of vegetation indices. The threshold point on the curve of the coefficient of variation was defined as the optimum resolution level for the analysis with multi-spatial resolution image sets. Also, the results from the image segmentation approach of region growing to extract man-made features were compared with these multi-spatial resolution image sets.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.232-236
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• 2000

Multi-regression statistical analyses were applied for the water quality data of shallow alluvial ground water (n = 47) collected from the Youngdeok area, in order to quantitatively generalize the natural (non-anthropogenic) causes of regional water quality variation. Seven samples having the high contamination index ( $C_{a}$ > 3) reflect the striong effects by anthropogenic activity. Most of the alluvial groundwaters have acquired their quality primarily due to the dissolution of carbonate minerals. The results of multi-regression analysis show that chlorine is mainly derived from seawater effect. Sulfur isotopic compositions of dissolved sulfur and the S $O_4$/Cl ratio also enable us to discriminate the samples (n = 18) which are affected by atmospheric input of marine aerosol (sea-spray) and also by mixing between freshwater and seawater. Hydrogen and oxygen isotope data of the samples collected lie close to the local meteoric water line obtained from nearby Pohang city but has lower slope (5.45) on the $\delta$D-$^{18}$ O plot, indicating that alluvial groundwater was recharged from infiltrated meteoric water which has undergone some degree of kinetic evaporation. The estimated initial isotopic composition of the recharged water ($\delta$D = -74.8$^{0}$ /$_{00}$, $\delta$$^{18}$ O = -10.8$^{[-1000]}$ /$_{[-1000]}$ ) suggests that the alluvial ground water recharge largely occurs during summer storm events.s.s.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.330-341
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• 2008

The purpose of this study was to investigate the vulnerability for groundwater contamination at the some cemeteries in Gyeonggi Province. Twenty-eight out of 43 cemeteries in Gyeonggi province were selected for this study. The DRASTIC model was applied to those cemeteries, and the reliance of the model was assessed using the water quality data of the target areas. The DRASTIC model was used for the assessment of the potential for groundwater contamination using hydrogeological factors. Seven factors including depth of water, net recharge, aquifer media, soil media, topography, impact of the vadose zone, hydraulic conductivity of the aquifer were assessed. The DRASTIC index of the study area ranged from 82 to 126 with an average value of $113.99(\pm11.48)$. The DRASTIC index was relatively greater in the northern Gyeonggi province than that in the southern area. The DRASTIC index was similar for the areas with the similar burial rate and burial density. This study demonstrated that burial rate and burial density should be considered along with the 7 basic factors for the evaluation of groundwater vulnerability of the cemeteries.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.781-790
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• 2019

Changes in the physical and chemical properties of soil materials during the nursing process have a great influence on the quality of containerized seedlings and on growth and survival after planting. In this study, the effect of biomaterials and their mixed ratios on the growth of Zelkova serrata seedlings in a containerized seedling production system was investigated. Mushroom sawdust, pine bark, and carbonized rice husk were used as biomaterials. The mixed ratios were 10% and 20% volume ratio of the growing medium volume, including the untreated controls. There was no significant difference in the height growth of the Zelkova serrata seedlings according to the biomaterials. The root collar diameter was the highest with the 20% carbonized rice husk and the lowest with the mushroom sawdust. The difference between the highest quality index and the lowest quality index was 30% in the order of the carbonized rice husk, pine bark, control, and mushroom sawdust, but there was no statistical significance. In this study, if the growing medium mixed with biomaterials does not reduce the seedling growth compared with the control, it is considered that the biomaterial can replace a part of the growing media. Therefore, the results show that some of the growing media can be replaced with carbonized rice husk or pine bark when producing Zelkova serrata seedlings.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.6
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• pp.53-63
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• 2012

The objectives of this study were to develop a linked watershed-waterbody modeling system and to assess the impacts of indirect wastewater reuse on irrigation water quality. The Osan stream watershed within Gyeonggi-do of South Korea was selected for this study. The linked modeling system was composed of the SWAT (Soil and water assessment tool) and QUALKO2 models. The SWAT model was calibrated and validated using the stream discharge and water quality data from 2010 to 2011. Runoff and non-point source pollutants from each subbasin and stream discharge from 1980 to 2009 were simulated by the SWAT model and applied to the QUALKO2 model. The QUALKO2 model was calibrated and validated under the conditions of low water and normal discharges, respectively. Finally, The 10-day irrigation water quality from April to September was simulated. The statistical measures of coefficient of determination ($R^2$), reliability index (RI), and efficiency index (EI) were used to evaluate the system performance. The $R^2$, RI and EI values ranged from 0.5 to 1.0, 1.03 to 1.92, and -35.03 to 0.95, respectively. The 10-day irrigation water quality showed the concentrations of BOD and coliform exceeded the water quality guidelines for wastewater reuse. The linked modeling system can be a useful tool to estimate non-point source pollutant loads in watershed and to control the water quality of effluent from a wastewater treatment plant and irrigation water in the downstream waterbody.

• Journal of Ecology and Environment
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• v.42 no.4
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• pp.163-173
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• 2018

Background: Deforestation and degradation are currently affecting the ecosystem services of forests. Among the ecosystem services affected by deforestation and degradation are the amount of soil organic carbon (SOC) and total nitrogen (TN) stored in forest soils which have greater impacts in global climate change. This study aimed at examining the amount of SOC and TN in the forest fragments which were separated from the continuous tracts of forests of Jibat and Chillimo through fragmentation processes over four decades. Methods: We have sampled soils from 15 forest fragments of Chillimo and Jibat in the central highlands of Ethiopia. The soil samples obtained in two separate soil depths (0-30 and 30-60 cm) were bulked, dried, and sieved for analysis. Results: Our results have shown that the two sites (Jibat and Chillimo forest fragments) differed in their SOC and TN contents. While the values for Jibat were found to be 29.89 Mg/ha of SOC and 2.84 Mg/ha for TN, it was 14. 06 Mg/ha of SOC and 1.40 Mg/ha for TN for Chillimo. When all forest fragment soil samples were bulked together, Jibat site had twice the value of SOC and TN than Chillimo. When disaggregated on the basis of each fragments, there existed differences in SOC (1.86 Mg/ha and 42.15 Mg/ha) and TN (0.24 Mg/ha and 4.23 Mg/ha) values. Among the forest fragments, fragment four ($F_4$) had the highest Relative Soil Improvement Index (RSII) value of 3826.82% and fragment fifteen ($F_{15}$) had the lowest RSII value (726.87%) which indicated that the former had a better quality of soil properties than the latter. Conclusion: SOC and TN differed across sampled fragments and sites. Variations in soil properties are the reflections of inherent soil parent material, aboveground vegetation, human interferences, and other physical factors. Such differences could be very important for identifying intervention measures for restoration and enhancing ecosystem services of those fragments.

• Journal of Korean Society of Forest Science
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• v.112 no.1
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• pp.23-31
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• 2023

Predicting forest productivity is essential to evaluate sustainable forest management or to enhance forest ecosystem services. Ordinary least squares (OLS) and partial least squares (PLS) regression models were used to develop predictive models for forest productivity (site index) from the site characteristics and soil profile, along with soil physical and chemical properties, of 112 Quercus mongolica stands. The adjusted coefficients of determination (adjusted R²) in the regression models were higher for the site characteristics and soil profile of B horizon (R²=0.32) and of A horizon (R²=0.29) than for the soil physical and chemical properties of B horizon (R²=0.21) and A horizon (R²=0.09). The PLS models (R²=0.20-0.32) were better predictors of site index than the OLS models (R²=0.09-0.31). These results suggest that the regression models for Q. mongolica can be applied to predict the forest productivity, but new variables may need to be developed to enhance the explanatory power of regression models.

• Journal of Biosystems Engineering
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• v.25 no.3
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• pp.195-202
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• 2000

This study was conducted to recognize a possibility that cone index can be used as a means of evaluating the tillage workability. Cone indexes were measured every 24 hours after rainfall at the experimental plots, and the rotary and plowing operations were conducted at the same time. The workability was evaluated on a basis of three categories of good, fair and poor depending on the quality of the performed works. Although the workability was affected by many factors such as soil type, moisture content ground slope and weather condition, the duration and amount of rainfall were of most influence. Results of the study showed that a good workability was resulted from the cone indexes greater than an average of 552 kPa for rotary operations and 671 kPa for plowing operations. Fair work was obtained with cone indexes greater than an average of 331 kPa for rotary operations and 459 kPa for plowing operations. The cone indexes less than an average of 171 kPa and 149 kPa resulted in poor workabilities for rotary and plowing operations, respectively. The experimental results may provide a general guideline for evaluating the tillage workability by cone index.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.54-61
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• 2014

This study was conducted to investigate the effect of Actinomyces sp. and Bacillus sp., United States granular microorganisms and Japan granular microorganisms on turfgrass growth and thatch decomposing of creeping bentgrass in golf course by measuring turf color index, chlorophyll index, thatch content of soil, root length, turf density and chemical properties and thatch content of soil. Fertilizer treatment was designed as follows; control(CF; compound fertilizer), microorganism medium(M; CF+M), microorganism medium and livestock manure fertilizer(M-L; CF+M+LMF), microorganism medium, livestock manure fertilizer and amino acid liquid fertilizer(M-L-A; MM+LMF+ALF), United States granular microorganisms(USGM; CF+USGM), Japan granular microorganisms(CF+JGM). Soil properties investigated after experiment was scarcely affected by applied fertilizers in root zone of creeping bentgrass. The turf color index and chlorophyll index of M, M-L, M-L-A, USGM, JGM treatment were higher than those of CF. The turfgrass root in M-L treatment was longer than others. The thatch content of soil in M treatment was longer than others. The thatch content of M was decreased than that of CF by 6.8%. These was suggested that application of M induced the development of quality and growth of creeping bentgrass by assisting turfgrass growth and thatch decomposing.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.521-528
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• 1999

As the size of our industry and population inclose, the byproducts such as municipal solid wastes, industrial wastes are in the increasing phase. The treatment of such things is rising as a social problem. Today, the final disposal of these wastes depends mostly on the landfill, and the sanitary landfill is required and designed for preventing soil and groundwater contamination. Clays have been used for a liner material of a sanitary landfill, however, the high quality clay is hard to come by and quite expensive as a lining material in our country. Using the waste lime produced abundantly every year from chemical processes was studied here, made from the proper mixing of the bentonite and the waste lime meets the regulations from the USEPA. The soil property index tests (sieve analysis, specific gravity test Atterberg limit test) were performed, and at last to confirm the sorption characteristics of the bentonite and the waste lime the sorption isotherm equilibrium test and the sorption isotherm were performed with Toluene and Ethylbenzene which are the main components of the leachate from the landfill.