• Korean Journal of Soil Science and Fertilizer
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• v.50 no.5
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• pp.345-356
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• 2017

We investigated 52 livestock farming complexes in Gyeong-Gi and Incheon provinces based on low, medium, and high livestock density and groundwater quality. The objective of this study was to evaluate a relationship between nitrate N concentration in groundwater and animal factors, such as livestock density and animal species. 2,200 groundwater samples for 3 years from 2012 to 2014 at Gyeong-Gi and Incheon provinces were collected and analyzed for pH, EC, DO, ORP, temperature, major anions and cations, such as $NO_3-N$, ${HCO_3}^-$, ${PO_4}^-$, ${SO_4}^{2-}$, $Cl^-$, $NH_4-N$, $K^+$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$, T-N, and TOC. Average concentration of total N for generated load density was $23,973g\;day^{-1}\;km^{-2}$ for cattle, $51,551g\;day^{-1}\;km^{-2}$ for pig, and $52,100g\;day^{-1}\;km^{-2}$ for poultry. For animal feeding species, average ratio for generated load over discharge load was 16.1% for cattle, 7.8% for pig, and 7.1% for poultry. Therefore, cattle feeding region is highly vulnerable for water pollution compared to pig and poultry feeding areas. The concentrations of chloride, nitrate, and total N in the groundwater samples were higher at high animal farming regions than other regions. The average concentration of nitrate, and chloride in groundwater samples was $5.0mg\;L^{-1}$, $16.6mg\;L^{-1}$ for low livestock density, $6.9mg\;L^{-1}$, $17.7mg\;L^{-1}$ for medium livestock density and $7.6mg\;L^{-1}$, $22.7mg\;L^{-1}$ for high livestock density and total nitrogen (T-N) was $7.7mg\;L^{-1}$ for low livestock density, $9.4mg\;L^{-1}$ for medium livestock density, $10.7mg\;L^{-1}$ for high livestock density. In conclusion, based on this research, for managing groundwater quality near livestock farming regions, $Ca-(Cl+NO_3)$ group from the Piper diagram is more efficient than using 19 factors for water quality standard.

• Korean Journal of Ecology and Environment
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• v.48 no.2
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• pp.77-85
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• 2015

Siniperca scherzeri is major target species for restocking and restoration project as it is one of the economic species in South Korea. In this study, to investigate their ecological characteristics movement pattern and habitat characteristic of S. scherzeri were analyzed using radio telemetry. Three specimens released during spawning season, moved more than 10 km toward upstream from the release site. Whereas the remains released after spawning season, settled within 400 m of their release site except two specimens (Ss 11, 3.2 km; Ss, 15, 1.4 km). One of possible reason of upstream movement during spawning season is reproduction. The conditions of their settlement area is similar with reference conditions of their spawning ground. S. scherzeri were mainly detected near the edge of the water, and it may related with the facts that rocks are mainly located at the edge of the water and S. scherzeri prefers rocks for their shelter. AMD (Accumulated movement distance) positively related with body weight and condition factor K, but no significant relationship was identified with gender and total length. Daily movement boundary of S. scherzeri was $214.94m^2{\sim}3,257.19m^2$, and their movement was restricted near the edge of the water. The results of this study could be useful to restocking and restoration.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.343-352
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• 1998

The relationship between summer hypoxia in bottom water layer and benthic community structure was discussed at forty sampling stations in semi-enclosed Youngsan River estuarine bay, Korea. The oxygen deficient layer less than $2.0 mg/\ell$ was widely developed in the inner estuarine stations in summer due to the summer stratification. A total of 141 species was occurred, with a mean density of $1,923 ind./m^2$ and biomass of $79.44\;g/m^2$ in summer season. The species number was significantly increased with the increment of the bottom dissolved oxygen, whereas density and biomass were partially correlated within the low oxygen level of $2.0\;mg/\ell$. These results imply that benthic community structures are affected by bottom oxygen depletion in summer. Cluster analysis showed that the benthic community could be classified into three station groups. These station groups from the species composition coincided with the groups based on the environmental factors. This fact suggests that the overall spatial distribution of macrozoobenthos in Youngsan River estuarine bay in summer should be controlled by the summer hypoxia and clay content of the area. Group-I was located the innermost estunrine bay from Mokpo Harbour to near the dike, where summer hypoxia was developed and one bivalve Theora fragilis, two polychaetes, Tharyx sp. and Lumbrineris longifolia were dominated. Group-II, the central transitory area of the estuarine bay between two another stational groups, where two bivalves Theora fragilis, Raetellops pulchella and a polychaete Tharyx sp. predominated with relatively low density compared to that of Group-I. Group-III, the mouth part of the estunrine bay exposed to the open sea, where a polychaetes Poecilochaetus johnsoni and a bivalve Yoldia Johanni predominated.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.1
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• pp.47-53
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• 2011

From 12 to 16 July 2006, 4 days' torrential rainfall in Deoksan-ri, Inje-up, Inje-gun, Gangwon-do caused massive landslide and debris flow. Huge losses of both life and property, including two people buried to death in submerged houses, resulted from this disaster. As the affected region is mostly mountainous, it was difficult to approach the region and to estimate the exact extent of damage. But using aerial photographs, we can define the region and assess the damage quickly and accurately. In this study the debris flow region in inje, Gangwon-do was analyzed using aerial photographs. This region was divided into three sections - beginning section, flow section and sedimentation section. Informations for each section were extracted by digitizing the shot images with visual reading. Topographic, forest physiognomic and soil characteristics and debris flow occurrences of this region were analyzed by overlaying topographic map, forest type map and soil map using GIS. Comprehensive analysis shows that landslide begins at slope of about $36^{\circ}$, flows down at $26^{\circ}$ slope, and at $21^{\circ}$ slope it stops flowing and deposits. Among forest physiognomic factors, species of trees showd significant relationship with debris flow. And among soil factors, effective soil depth, soil erosion class, and parent materials showed meaningful relationship with debris flow.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.322-326
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• 2016

The distribution of floodplain vegetation is mainly affected by hydrological and hydraulic processes. In this study, we investigated changes in the vegetation distribution due to flood discharge alteration, and the relationship between the vegetation types and the flood frequency during the last ten-year period in the Cheongmi-cheon Stream. Flood discharge of the Cheongmi-cheon Stream tended to decrease from 2006 to 2016. It has greatly decreased to less than $160m^3/s$ since 2013. This resulted in the settlement of Phragmites japonica to the wide sand bar at the Cheongmi-cheon Stream, even though it had sparse vegetation before 2013. The sand bar was fully covered with P. japonica in 2016. Vegetation communities in the floodplain were classified by dominant species, i.e. the annual-hygrophytic, the perennial hygrophytic and the mesophytic communities. Analysis of the relationship between the vegetation communities and the flood frequency shows the annual hygrophytes, perennial hygrophytes and the mesophytes communities distributed in the range of under 1 year, 1-10 year and over 7 year flood inundation area, respectively. In conclusion, distribution of the floodplain vegetation is closely related with the flood discharge and frequency in the Cheongmi-cheon Stream.

• Journal of Environmental Impact Assessment
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• v.29 no.3
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• pp.230-238
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• 2020

This study inferred the ecology of habitat use of the wild boars (Sus scrofa) in Yeongwol Hanbando wetland through DNA analysis using non-invasive samples of hairs. From November 2018 to May 2019, hair samples were collected from rubbing trees and hairtraps within the Hanbando wetland (2.772 ㎢). We extracted DNA from the hair samples and conducted PCR to verify the species and identify sex of the individuals. In addition we analysed 6 microsatellite markers to identify individuals and genetic relationship among the pairs of individuals. A total of 16 boar hairs were sampled, which turned out to be from 10 individual (7 females and 3 males) boars. We found that 9 pairs, out of 45 possible pairs, were most likely to be relatives. The result from kinship data and the location of the sampled hairs suggest that wild boars in this area live as family groups that consist of a mother and her offspring, which is consistent with known habits of wild boars. It is needed to include more samples and microsatellite markers for better precise estimation of kinship among the boar individuals.

• Analytical Science and Technology
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• v.29 no.1
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• pp.19-28
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• 2016

The objective of this study was to determine the acidification of precipitation in the Jeju area. Precipitation samples were collected from the Jeju area from 2009-2014, and the major ionic species were analyzed. In the regression analysis, through a comparison of ion balance, electric conductivity, and acid fraction, the correlation coefficients showed a good linear relationship within the range of 0.927~0.983. The volume-weighted means of the pH and electric conductivity were 4.9 and 22.7 µS/cm, respectively. The ionic strength of precipitation was 0.27±0.38 mM, indicating about 35.9 % of total precipitation within the pure precipitation criteria. The volume-weighted mean concentrations (ìeq/L) of the ionic species in the precipitation were in the order of Na⁺ > Cl⁻ > nss-SO₄²⁻ > NO₃⁻ > NH₄⁺ > Mg²⁺ > H⁺ > nss-Ca²⁺ > PO₄³⁻ > K⁺ > HCOO⁻ > CH₃COO⁻ > NO₂⁻ > F⁻ > HCO₃⁻ > CH₃SO₃⁻ . The acidification contributions by sulfuric and nitric acids were 54.5 % and 36.5 %, respectively. Meanwhile the acidification contributions by formic and acetic acids were 4.8 % and 4.2 %, respectively. Thus, it was found that the acidification of the precipitation in the Jeju area was mainly due to the inorganic acids. The neutralization factors by NH₃ and CaCO₃ were also 33 % and 20 %, respectively.

• Korean Journal of Remote Sensing
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• v.33 no.5_1
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• pp.571-585
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• 2017

The number of spaceborne optical sensors including red-edge band has been increasing since red-edge band is known to be effective to enhance the information content on biophysical characteristics of vegetation. Considering that the Agriculture and Forestry Satellite is planning to carry an imaging sensor having red-edge band, we tried to analyze the current status and potential of red-edge band. As a case study, we analyzed the effect of using red-edge band and tried to find the optimum band width and wavelength region of the red-edge band to estimate leaf area index (LAI) of very dense tree canopy. Field spectral measurements were conducted from April to October over two tree species (white oak and pitch pine) having high LAI. Using the spectral measurement data, total 355 red-edge bands reflectance were simulated by varying five band width (10 nm, 20 nm, 30 nm, 40 nm, 50 nm) and 71 central wavelength. Two red-edge based spectral indices(NDRE, CIRE) were derived using the simulated red-edge band and compared with the LAI of two tree species. Both NDRE and CIRE showed higher correlation coefficients with the LAI than NDVI. This would be an alternative to overcome the limitation of the NDVI saturation problem that NDVI has not been effective to estimate LAI over very dense canopy situation. There was no significant difference among five band widths of red-edge band in relation to LAI. The highest correlation coefficients were obtained at the red-edge band of center wavelength near the 720 nm for the white oak and 710 nm for the pitch pine. To select the optimum band width and wavelength region of the red-edge band, further studies are necessary to examine the relationship with other biophysical variables, such as chlorophyll, nitrogen, water content, and biomass.

• Journal of Korean Society of Forest Science
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• v.81 no.3
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• pp.214-223
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• 1992

To investigate the structure of the plant community of Mt. Jookyup area in Kwangnung forest, thirty-seven plots were set up by the clumped sampling method. The classification by TWINSPAN and two kinds of multivariate ordination(RA, DCA) were applied to the study area in order to classify them into several groups based on woody plants and environmental variables. The classification have been successfully overlayed on an ordination of the same data using DCA. The plots can be classified into five groups by TWINSPAN and DCA. The successional trends of tree species by both techniques seem to be expected two ways in the canopy layer. The first is from Pinus densiflora to Carpinus laxiflora and the second is from Pinus densiflora through Quercus mongolica to Carpinus laxiflora. In the understory layer, it was expected that Rhododendron mucronulatum ${\rightarrow}$Lindera obtusiloba, Symplocos chinensis for. pilosa, Viburunum erasum, Styrax obassia${\rightarrow}$Euonymus sachalinensis, Sorbus alnifolia. As the result of the analysis for the relationship between the stand scores of DCA and environmental variables, they had a tendency to increase significantly from the P. densiflora community to Quercus spp. community that was soil pH, total nitrogen, available phosphate and exchangeable potassium, sodium, calcium and magnesium.

• Ocean and Polar Research
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• v.38 no.3
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• pp.195-207
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• 2016

Because the high latitude region in the North Pacific is characterized by high primary production in the surface water enriched with nutrients, it is important to understand the variation of surface water productivity and associated nutrient variability in terms of global carbon cycle. Surface water productivity change or its related nutrient utilization rate during the Northern Hemisphere Glaciation (NHG; ca. 2.73 Ma) has been reported, but little is known about such circumstances under gradual climate cooling since the NHG. Bulk nitrogen isotope (${\delta}^{15}N_{bulk}$) of sedimentary organic matter has been used for the reconstruction of nutrient utilization rate in the surface water. However, sedimentary organic matter experiences diagenesis incessantly during sinking through the water column and after burial within the sediments. Thus, in this study we examine the degree of nitrate utilization rate during the early Pleistocene (2.4-1.25 Ma) since the NHG, using the diatom-bound nitrogen isotope (${\delta}^{15}N_{db}$), which is known to be little influenced by diagenesis, from Site U1343 in the Bering slope area. ${\delta}^{15}N_{db}$ values range from ~0.5 to 5.5‰, which is lower than ${\delta}^{15}N_{bulk}$ values, but they vary with larger amplitude. Variation patterns between ${\delta}^{15}N_{db}$ values and biogenic opal concentration are generally consistent, which indicates that the nitrate utilization rate is closely related to opal productivity change in the surface water. A positive correlation between opal productivity and nitrate utilization rate was observed, which is different from the other high latitude regions in the North Pacific. The main reason for this contrasting relationship is that the primary production in the surface water at Site U1343 is influenced mostly by the degree of sea ice formation. Still, although concerns about diagenetic alteration have been avoided by using ${\delta}^{15}N_{db}$, the effects of the preservation state of biogenic opal and the species-dependent isotopic fractionation on ${\delta}^{15}N_{db}$ should be assessed in the future studies.