• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.179-191
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• 2019

Heavy metals in stream water and sediments around industrial complex were studied in order to assess the contamination and to identify the potential source of metals. High variability has been observed for both dissolved and particulate phases in stream water with coefficient of variation (CV) ranging from 1.3 to 2.8. The highest metal concentrations in both phases were observed in Gunja for Ni and Cu, in Jungwang for Zn and Pb and in Shiheung for Cd, respectively. These results indicate that the different metal sources could be existing. The concentrations of the heavy metals in sediments decreased in the order of Cu>Zn>Pb>Cr>Ni>As>Cd>Hg, with mean of 2,549, 1,742, 808, 539, 163, 17.1, 5.8, $0.07mg\;kg^{-1}$, respectively. Mean of metal concentrations(except for As) in sediments showed the highest values at Shiheung stream comparing with other streams. In sediments, the percent exceedance of class II grade that metal may potentially harmful impact on benthic organism for Cr, Ni, Cu, Zn, Cd, Pb was about 57%, 62%, 84%, 60%, 68%, 81% for all stream sediments, respectively. Sediments were classified as heavily to extremely polluted for Cu and Cd, heavily polluted for Zn and Pb, based on the calculation of Igeo value. About 59% and 35% of sediments were in the categories of "poor" and "very poor" pollution status for heavy metals. Given the high metal concentrations, industrial wastes and effluents, having high concentrations of most metals originated from the manufacture and use of metal products in this region, might be discharged into the stream through sewer outlet. The streams receive significant amounts of industrial waste from the industrial facilities which is characterized by light industrial complexes of approximately 17,000 facilities. Thus, the transport of metal loads through streams is an important pathway for metal pollution in Shihwa Lake.

• Korean Journal of Environment and Ecology
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• v.31 no.1
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• pp.112-118
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• 2017

The purpose of this study is to clarify the characteristics of the soundscape in a natural park and an urban park. The study sites were a natural park (Chiaksan Nationalpark) and an urban park (Rose Park) in Wonju City, Gangwon Province. Soundscape recording was conducted using Digital Recorder from April 2015 to January 2016. The analysis period was 8 days per season, with a total of 64 days (2 places). Analysis items were soundscape's daily cycle, soundscape type, and seasonal variation. According to the result of the daily cycle analysis of the soundscape, the natural park was dominated by the biophony in accordance with the cycle of the sun, and the airplane sound was observed in the daytime. Meanwhile, anthrophony was consistently produced in the urban park 24 hours a day. As a result of the detailed type analysis of the soundscape, the sources of biophony were classified into wild birds, mammals, insects and amphibians, and the sources of geophony were classified into rain and wind. The anthrophony was mostly airplane sound. In the urban park, wild birds appeared to most influence the biophonic sounds while rain and the wind were the most frequent sounds that contribute to geophony. The most influential components of anthrophony in the urban park were in the order of automobiles, people, music, construction, cleaning, and airplane sound. As a result of the seasonal difference analysis of the soundscape, it was statistically significant that the natural park shows higher biophony in spring, summer, and autumn compared to the urban park. Anthrophony in the urban park appeared to be higher than the natural park in all seasons. The significance of this study is that it is the first study to identify the characteristics of the soundscape of a natural park and an urban park emanating from different landscapes in South Korea.

• Korean Journal of Environment and Ecology
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• v.22 no.4
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• pp.427-434
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• 2008

The studies of seven individuals of Asiatic black bears were carried out with radio telemetry from October 2004 to December 2006 in Jirisan National Park. They were attached radio-transmitter and calculated by the 95%MCP and fixed kernel method(95%, 50%). As a result, Mean annual home ranges for female and male asiatic black bears were 71.66$km^2$ and 90.20$km^2$. The seasonal home ranges were calculated 19.81$km^2$ for females and 33.47$km^2$ for males in spring, 30.48$km^2$ for females and 20.26$km^2$ for males in summer, 22.63$km^2$ for females and 23.23$km^2$ for males in autumn and 0.22$km^2$ for females and 0.78$km^2$ for males in winter(F=4.193, P<0.05). The degree of home range overlapped 38%, 12.5% among females, 22.4% among males. Mean elevation of seven bears was 744$\pm$236m in spring, 682$\pm$253m in summer, 937$\pm$218m in fall and 975$\pm$137m in winter(F=8.526, P<0.001). It is assumed that home range sizes and location were closely correlated to environmental characteristics of the habitats and the seasonal variation of home-range was related to distribution of food sources.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.3
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• pp.75-88
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• 2016

In this study, we used the CLUE-s model to predict the future land-use change based on the urban growth scenario in South Korea. The land-use maps of six classes (water, urban, rice paddy, upland crop, forest, and grass) for the year 2008 were obtained from the Ministry of Environment (MOE), and the land-use data for 5-year intervals between 1980 and 2010 were obtained from the Water Resources Management Information System (WAMIS), South Korea. For predicting the future land-use change, the MOE environmental conservation value assessment map (ECVAM) was considered for identifying the development-restricted areas, and various driving factors as location characteristics were prepared for the model. The predicted results were verified by comparing them with the land-use statistics of urban areas in each province for the year 2008. The prediction error rates were 9.47% in Gyeonggi, 9.96% in Gangwon, 10.63% in Chungbuk, 7.53% in Chungnam, 9.48% in Jeonbuk, 6.92% in Jeonnam, 2.50% in Gyeongbuk, and 8.09% in Gyeongnam. The sources of error might come from the gaps between the development of political decisions in reality with spatio-temporal variation and the mathematical model for urban growth rate in CLUE-s model for future scenarios. Based on the land-use scenario in 2008, the land-use predictions for the year 2100 showed that the urban area increased by 28.24%, and the rice paddy, upland crop, and forest areas decreased by 8.27, 6.72, and 1.66%, respectively, in South Korea.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.329-337
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• 2013

This study was performed to evaluate the temporal and spatial variations of the water quality at stream flowing into the Suncheon bay in Suncheon city from October 2008 to August 2009 and to estimate the pollutant sources from the streams using multivariate analysis. Water qualities from Seo stream, Dong stream, Ok stream were evaluated as I grade(very good) that compared to the Water Quality Standard. But Haeryong stream and inlet site of Suncheon Bay in BOD were evaluated as a little bad and fair. Water quality at the stream flowing into the Suncheon Bay was could be explained up to 92.8% by three factors which were included in loading of nutrients, organic matter and total coliform group by the allochthonous matters(53.7%), Topographic Factors(25.0%), seasonal variation(14.2%). The concentrations of total nitrogen and phosphorus at sewage treatment plant and organic matters at Haeryong stream were higher than that of others, respectively. From principal component analysis and factor analysis, it could be suggested that it is very important to make an effort to reduce the nutrients and organic matters from sewage treatment plant and Haeryong stream to be in good conservation of the Suncheon bay.

• Journal of Marine Life Science
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• v.1 no.1
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• pp.1-7
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• 2016

In order to assess seasonal and geographical characteristics of pollutant Escherichia coli, we investigated its distribution in Nakdong River mouth and Busan coastal water from February 2013 to November 2015. The coastal area was divided into five different zones (I-V) based on the pollutant level and geographical characteristics. During the study periods, water temperature and salinity varied from 7.50 to 27.64℃ and 16.82 to 34.82 psu, respectively. The annual water temperature variation was characterized in temperate zone. The salinity was significantly (p<0.05) decreased in zone IV and zone III after heavy rain during summer season in 2014, resulting led to elevated E. coli biomass. The highest colony formation of E. coli was recorded at 6,000 cfu l^-1 during autumn at station 1 (zone I). On the other hands, during all seasons of 2015, E. coli abundances were kept to be low level in zone III. The E. coli was not significantly (p>0.05) correlated with water temperature. However, the salinity was significantly (r=-0.53, p<0.05) correlated with the E. coli, implying that salinity plays a crucial role in the proliferation of E. coli. Consequently, E. coli in western Busan coastal water might have been significantly promoted by pollutant sources from Nakdong Rive discharge during the spring and summer rainy seasons depending on annual rainfall variations. On the other hands, E. coli in station 1 (i.e., Suyeong Bay) was obviously high due to influences of discharge water from municipal wastewater treatment plant. However, there was no clear seasonality of E. coli.

• Journal of Korea Water Resources Association
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• v.47 no.9
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• pp.825-838
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• 2014

The stationary Markov chain model has been widely used as a daily rainfall simulation model. A main assumption of the stationary Markov model is that statistical characteristics do not change over time and do not have any trends. In other words, the stationary Markov chain model for daily rainfall simulation essentially can not incorporate any changes in mean or variance into the model. Here we develop a Non-stationary hidden Markov chain model (NHMM) based stochastic downscaling scheme for simulating the daily rainfall sequences, using general circulation models (GCMs) as inputs. It has been acknowledged that GCMs perform well with respect to annual and seasonal variation at large spatial scale and they stand as one of the primary sources for obtaining forecasts. The proposed model is applied to daily rainfall series at three stations in Nakdong watershed. The model showed a better performance in reproducing most of the statistics associated with daily and seasonal rainfall. In particular, the proposed model provided a significant improvement in reproducing the extremes. It was confirmed that the proposed model could be used as a downscaling model for the purpose of generating plausible daily rainfall scenarios if elaborate GCM forecasts can used as a predictor. Also, the proposed NHMM model can be applied to climate change studies if GCM based climate change scenarios are used as inputs.

• Economic and Environmental Geology
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• v.56 no.3
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• pp.331-341
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• 2023

When creating a soil contamination map using geostatistical techniques, there are various sources that can affect prediction errors. In this study, a grid-based soil contamination map was created from the sampling data of heavy metal concentrations in soil in abandoned mine areas using Ordinary Kriging. Five factors that were judged to affect the prediction error of the soil contamination map were selected, and the variation of the root mean squared error (RMSE) between the predicted value and the actual value was analyzed based on the Leave-one-out technique. Then, using a machine learning algorithm, derived the top three factors affecting the RMSE. As a result, it was analyzed that Variogram Model, Minimum Neighbors, and Anisotropy factors have the largest impact on RMSE in the Standard interpolation. For the variogram models, the Spherical model showed the lowest RMSE, while the Minimum Neighbors had the lowest value at 3 and then increased as the value increased. In the case of Anisotropy, it was found to be more appropriate not to consider anisotropy. In this study, through the combined use of geostatistics and machine learning, it was possible to create a highly reliable soil contamination map at the local scale, and to identify which factors have a significant impact when interpolating a small amount of soil heavy metal data.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.142-149
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• 2011

An isocratic high performance liquid chromatography (HPLC) method for routine analysis of deoxynivalenol in noodles was validated and estimated the measurement uncertainty. Noodles (dried noodle and ramyeon) were analyzed by HPLC-ultraviolet detection using immunoaffinity column for clean-up. The limits of detection (LOD) and quantification (LOQ) were 7.5 ${\mu}g$/kg and 18.8 ${\mu}g$/kg, respectively. The calibration curve showed a good linearity, with correlation coefficients $r^2$ of 0.9999 in the concentration range from 20 to 500 ${\mu}g$/kg. Recoveries and Repeatabilities expressed as coefficients of variation (CV) spiked with 200 and 500 ${\mu}g$/kg were $82{\pm}2.7%$ and $87{\pm}1.3%$% in dried noodle, and $97{\pm}1.6%$ and $91{\pm}12.0%$ in ramyeon, respectively. The uncertainty sources in measurement process were identified as sample weight, final volume, and sample concentration in extraction volume as well as components such as standard stock solution, working standard solution, 5 standard solutions, calibration curve, matrix, and instrument. Deoxynivalenol concentration and expanded uncertainty in two matrixes spiked with 200 ${\mu}g$/kg and 500 ${\mu}g$/kg were estimated to be $163.8{\pm}52.1$ and $435.2{\pm}91.6\;{\mu}g$/kg for dried noodle, and $194.3{\pm}33.0$ and $453.2{\pm}91.1\;{\mu}g$/kg for ramyeon using a coverage factor of two which gives a level of statistical confidence with approximately 95%. The most influential component among uncertainty sources was the recovery of matrix, followed by calibration curve.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.153-165
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• 2001

We evaluated the health condition of Pyong-Chang river, the tributary of Han- River, using the Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) during September 1999${\sim}$August 2000. The annual mean of IBI,　which was estimated using eleven metrics, was 49 (range: $45{\sim}51$) and the mean of QHEI, which was estimated using seven parameters, was 88 (range: $76{\sim}94$) during　the study. The river health, based on the IBI criteria of Karr (1981), ranged from "excellent" to "good" conditions, while based on the habitat criteria of Plafkin et al. (1989), it ranged from "pristine" (comparable to reference) to "supporting" conditions. Values of IBI showed slight differences between upstream and downstream sites and QHEI values varied weakly depending on characteristics of variables. Regression analyses showed that annual values of QHEI had no functional relations with stream order (p = 1.82; n = 8) but showed some decreases near slight point-sources. This result indicates that conditions of physical habitat did not change highly with increases of the stream order. According to analyses of feed guilds, relative abundance of insectivores, omnivores and carnivores was 85.1%, 3.5% 0.3%, respectively. Also, relative abundance of sensitive and tolerant species was 75% and 4.6%, respectively, while exotic and morphological anomalies were not found in the river. These outcomes indicate that health condition of fish, based on the trophic conditions of U.S. EPA (1993), was excellent in the river. Regression analyses of IBI values against the QHEI showed that the variation of habitat conditions accounted 57% for the variation of the Index of Biological Integrity (p<0.05; $R^2\;=\;0.57$; n = 7).Overall data of IBI and QHEI suggest that the river health in the present is in optimal conditions but may be degradated by acceleration of chemical inputs and physical-habitat disturbance.