• Korean Journal of Ecology and Environment
• /
• v.39 no.1 s.115
• /
• pp.110-118
• /
• 2006

The Namyang Stream in Hwaong polder was planned for several water uses including recreation, where people can contact the water and consume some amount during the recreational activity. A human health risk was assessed from exposure to E. coli in the Namyang Stream, which receives partially treated wastewater from watershed. The QUAL2E model was applied to simulate stream water quality, and this model was calibrated and verified with field monitoring data. The calibration result showed a high correlation coefficient of greater than 0.9. The mean concentration of E. coli in the Namyang Stream from the QUAL2E output was in the range of 5,000 ${\sim}$ 8,000 MPN 100 mL^{-1}$, which exceeded national and international guidelines. The Beta-Poisson was used to estimate the microbial risk of pathogens ingestion and the Monte-Carlo analysis (10,000 trials) was used to estimate the risk characterization of uncertainty. The Microbial risk assessment showed that the risk ranged from 7.9 ${\times}\;10^{-6}\;to\;9.4\;{\times}10^{-6}$. Based on USEPA guidelines, the range of $10^{-6}\;to\;10^{-8}$ was considered reasonable levels of risk for communicable disease transmission from environmental exposure, and the risk above $10^{-4}$ was considered to be in the danger of infection. Therefore, water quality of the Namyang Stream might not be in the danger of infection although it exceeded national and international guidelines. However, it was in the range of communicable disease transmission, and thorough wastewater collection and treatment at the source is recommended to secure safe recreation water quality.

• Journal of Soil and Groundwater Environment
• /
• v.13 no.5
• /
• pp.57-73
• /
• 2008

Nitrate concentrations were measured up to 49 mg/L (as $NO_3$-N) and 22% of the samples exceeded drinking water standard in shallow and bedrock groundwater of the northern Nonsan area. Nitrate concentrations showed a significant difference among land use groups. To predict nitrate concentration in groundwater, multiple regression analysis was carried out using hydrogeologic parameters of soil media, topography and land use which were categorized as several groups, well depth and altitude, and field parameters of temperature, pH, DO and EC. Hydrogeologic parameters were quantified as area proportions of each category within circular buffers centering at wells. Regression was performed to all the combination of variables and the most relevant model was selected based on adjusted coefficient of determination (Adj. $R^2$). Regression using hydrogelogic parameters with varying buffer radii show highest Adj. $R^2$ at 50m and 300m for shallow and bedrock groundwater, respectively. Shallow groundwater has higher Adj. $R^2$ than bedrock groundwater indicating higher susceptibility to hydrogeologic properties of surface environment near the well. Land use and soil media was major explanatory variables for shallow and bedrock groundwater, respectively and residential area was a major variable in both shallow and bedrock groundwater. Regression involving hydrogeologic parameters and field parameters showed that EC, paddy and pH were major variables in shallow groundwater whereas DO, EC and natural area were in bedrock groundwater. Field parameters have much higher explanatory power over the hydrogeologic parameters suggesting field parameters which are routinely measured can provide important information on each well in assessment of nitrate contamination. The most relevant buffer radii can be applied to estimation of travel time of contaminants in surface environment to wells.

• Economic and Environmental Geology
• /
• v.28 no.2
• /
• pp.109-121
• /
• 1995

The hydrothermal vein type deposits which comprise the Kasihan, Jompong and Gempol mineralized areas are primarily copper and zinc deposits, but they are also associated with lead and/or gold mineralization. The deposits occur within the Tertiary sedimentary and volcanic rocks in the Southern Mountain zone of the eastern Java island, Indonesia. Mineralization can be separated into two or three distinct stages (pre-and/or post- ore mineralization stages and main ore mineralization stage) which took place mainly along pre-existing fault breccia zones. The main phase of mineralization (the main ore stage) can be usually classified into three substages (early, middle and late) according to ore mineral assemblages, paragenesis, textures and their chemical compositions. Ore mineralogy and paragenesis of the three areas in the district are different from each other. Pyrite, pyrrhotite (/arsenopyrite), iron-rich (up to 20.5 mole % FeS) sphalerite and (Cu-)Pb-Bi sulfosalts are characteristic of the deposits in the Kasihan (/Jompong) area. On the other hand, pyrite + hematite + magnetite + iron-poor (2.7 to 3.6 mole % FeS) sphalerite assemblage is restricted to the Gempol area. Fluid inclusion data suggest that fluids of the main ore stage evolved from initial high temperatures (near $350^{\circ}C$) to later lower temperatures (near $200^{\circ}C$) with salinities ranging from 0.8 to 10.1 equiv. wt. percent NaCl. Each area represents a separate hydrothermal system: the mineralization at Kasihan and Jompong were largely due to early fluid boiling coupled with later cooling and dilution, whereas the mineralization at Gempol was mainly resulted from cooling and dilution by an influx of cooler meteoric waters. Fluid inclusion evidence of boiling indicates that pressures of ${\geq}95$ to 255 bars (${\geq}95$ bars for the Gempol area: $\approx$ 120 to 170 bars for the Jompong area: $\approx$ 140 to 255 bars for the Kasihan area) during portions of main ore stage mineralization. Equilibrium thermodynamic interpretation indicates that the evolution trends of the temperature versus fS2 variation of ore stage fluids in the Pacitan district follow two fashions: ore fluids at Kasihan and Jompong changed from the pyrite-pyrrhotite sulfidation stage towards pyritehematite- magnetite state, whereas those at Gempol evolved nearly along pyrite-hematite-magnetite reaction curve with decreasing temperature. The sulfur isotope compositions of sulfide minerals are consistent with an igneous source of sulfur with a ${\delta}^{34}S_{{\Sigma}s}$ value of about 3.3 per mil. The oxygen and hydrogen isotopic compositions of the fluids in each area indicate a progressive shift from the dominance of highly exchanged meteoric water at early hydrothermal systems towards an un- or less-exchanged meteoric water at later hydrothermal systems.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.31 no.1
• /
• pp.38-47
• /
• 2013

This study was performed in order to preserve and protect the scenic sites and surrounding environment is located in the Urban Residential Area. After classifying the type of area surrounding parcels of Seongbuk-dong is located in Seongragwon, Satisfaction Survey, scenic sites designated areas for residents living near the analyzed. Research methods, Cadastral research, literature survey, field survey, and the survey was conducted. Cultural heritage awareness about the collected questionnaires of frequency analysis, and reliability analysis for cultural heritages around satisfaction, satisfaction analysis by parcel area, parcel area for the verification of specific differences regression analysis for the full-on relationship satisfaction, one-way ANOVA was conducted for each. Overall Cultural awareness analysis results, the residence is located close to the Seoul Seonjamdanji, Seongragwon, Simujang, Sanghoe Lee Tae-Joon's houses, Seoul Hanyang castle showed that cultural heritage were know unfulfilled cultural heritage. The purpose of cultural heritage visit was to break/walks. Preservation was usually level and there is no inconvenience caused as a cultural heritage. Regulatory intensity level was usually level and showed a positive reaction to the impact of cultural heritage in Seongbuk-dong image mostly. cultural heritage have a positive impact on the image of the town. but access to cultural heritage is not easy and doesn't affect the life is expected. Overall satisfaction for cultural heritages in the surrounding space, the larger the size of the lot, and higher satisfaction. Seongbuk-dong most of the residents satisfaction was higher. Small lots of residents showed low satisfaction for safety when walking at night, heritage value rise, private ownership of heritage use, harmony with surrounding environment, Building exterior, non-physical uniqueness like culture art mental. It can be interpreted that small lots of residential environment quality is low compared to the large lots, influx of residents in other regions due to the redevelopment of one of Seongbuk-dong, private ownership of heritage use. And generally lower satisfaction on the harmonization of the facility(street lights, signs, etc.). Therefore cultural heritage signs for facility expansion, cultural educational programs, will be needed to maintain the uniqueness village when scenic sites in the city center around the area of management strategy.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.14 no.1
• /
• pp.40-50
• /
• 2011

We study the characteristic and total flux of non-point pollutants such as total suspended solids (TSS), chemical oxygen demand (COD), dissolved nutrients, total phosphorus (TP) and total nitrogen (TN) in the storm water runoff from urban streams and sewer outlets of Banweol Industrial Complex around Shihwa Lake. The concentrations of non-point pollutants were generally increased with increasing of the duration and intensity of rainfall. Mean TSS concentration of Ansan stream was higher than that of sewer outlets but mean concentrations of COD, TP and TN were approximately 2~5 times higher of sewer outlet than of urban stream. TSS showed statistically positive relationships with COD and TP but it had negative correlation with dissolved nutrients. There was a significant correlation between total flux of non-point pollutants in the storm water runoff and total basin area of each sewer outlet, showing that the highest runoff flux was observed at 3rd sewer outlet which represents the largest basin area from Banweol industrial complex. Total runoff fluxes for TSS, COD, TP and TN in this study were 187,536 kg, 17,118 kg, 922 kg, 13,519 kg, respectively. Given the basin area of sewer outlet in Banweol industrial complex which corresponds only 3% from total catchment area around Shihwa Lake, enormous amount of non-point pollutants will be entered into Shihwa Lake without any treatment. It is necessary to manage and reduce of various non-point sources and pollutants because the runoff of nonpoint pollutants during storm events should be deteriorating the water quality of Shihwa Lake. Our results provides useful informations on the development of best managements practices (BMPs) for effective implementation of total pollution loads management system of Shihwa Lake.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.12 no.3
• /
• pp.95-111
• /
• 2004

This research sought to determine the status of the installation and operation of composting facilities of domestic public resource-making facilities and come up with corresponding improvement measures. The composting facilities were the most extensively installed of related facilities with over a 0.5 ton treated volume per day. The monthly and yearly carry-in volume of food waste were found to stand at 1,101.7 tons per day and 930.9 tons per day, thus falling short of the average planned volume of 1,270.9 tons. Many composting facilities, which were installed in areas for which factory registration were not approved, did not get approvals. Composting facilities underwent operation stoppage mainly due to faulty fermentation and crushing equipment. Mainly metals contained in food waste caused faults to the crushing equipment, thus requiring a facility designing against faults and corrosion. The initial water content was found to stand at 50-60%, thus complying with the requirement. However, since the composting food waste had an appropriate mixture of sawdust, food waste, and returned compost, it should meet the initial conditions. For fermentation facilities, the duration time for fermentation was 15 days, and post-fermentation tanks required 21 days of duration time, thus establishing the minimum criteria. However, some facilities did not meet the requirements, taking more time in decomposition, thus suggesting a need to determine the duration time according to facilities. In composting food waste, microorganism-based thermal oxidizer-operated fermentation tanks should be used to ensure an economic operation. On the contrary, 14 out of 25 survey targets heated fermentation tanks in any form. These thermal facilities contain the growth of bacteria, lowering chemical reaction in composting; thus composting facilities should be basically designed to use microorganism-based thermal oxidizers in drying water. An average daily volume of food waste and supplementary materials that was injected in producing compost was 22.8 tons. This volume produced 7.3 tons of compost per day, decreasing 68%. Properties of produced compost were analyzed by its color, absence or presence of remaining decomposition heat, and smell, to assess the quality. As a result, the composting process was not properly installed nor operated in about 50% of composting facilities. Compost should be produced to be soil-friendly.

• Korean journal of applied entomology
• /
• v.48 no.2
• /
• pp.123-158
• /
• 2009

An attempt was made to stimulate future research by providing exemplary information, which would integrate published knowledge to solve specific pest problem caused by resistance. This review was directed to find a way for delaying resistance development with consideration of chemical(s) nature, of mixture, rotation, or mosaics, and of insecticide(s) compatible with the biological agents in integrated pest management (IPM). The application frequency, related to the resistance development, was influenced by insecticide activity from potentiation, residual period, and the vulnerability to resistance development of chemical, with secondary pest. Chemical affected feeding, locomotion, flight, mating, and predator avoidance. Insecticides with negative cross-resistance by the difference of target sites and mode of action would be adapted to mixture, rotation and mosaic. Mixtures for delaying resistance depend on each component killing very high percentage of the insects, considering allele dominance, cross-resistance, and immigration and fitness disadvantage. Potential disadvantages associated with mixtures include disruption of biological control, resistance in secondary pests, selecting very resistant population, and extending cross-resistance range. The rotation would use insecticides in high and low doses, or with different metabolic mechanisms. Mosaic apply insecticides to the different sectors of a grid for highly mobile insects, spray unrelated insecticides to sedentary aphids in different areas, or mix plots of insecticide-treated and untreated rows. On the evolution of pest resistance, selectivity and resistance of parasitoids and predator decreased the number of generations in which pesticide treatment is required and they could be complementary to refuges from pesticides To enhance the viability of parasitoids, the terms on the insecticides selectivity and factors affecting to the selectivity in field were examined. For establishment of resistant parasitoid, migration, survivorship, refuge, alternative pesticides were considered. To use parasitoids under the pressure of pesticides, resistant or tolerant parasitoids were tested, collected, and/or selected. A parasitoid parasitized more successfully in the susceptible host than the resistant. Factors affecting to selective toxicity of predator are mixing mineral oil, application method, insecticide contaminated prey, trait of individual insecticide, sub-lethal doses, and the developmental stage of predators. To improve the predator/prey ratio in field, application time, method, and formulation of pesticide, reducing dose rate, using mulches and weeds, multicropping and managing of surroundings are suggested. Plant resistance, predator activity, selective insect growth regulator, and alternative prey positively contributed to the increase of the ratio. Using selective insecticides or insecticide resistant predator controlled its phytophagous prey mites, kept them below an economic level, increased yield, and reduced the spray number and fruits damaged.

• 한국해양학회지
• /
• v.21 no.1
• /
• pp.13-24
• /
• 1986

The daily net primary production by phytoplankton in the southeastern sea of Korea in October 1985 ranged from 0.7 to 2.7 gCm$\^$-2/ d$\^$-1/ and averaged to be 1.3 gCm$\^$-2/ d$\^$-1/. Surface total chlorophyll ranged from 0.97 to 3.59mg chlm$\^$-3/. Primary production by nano-phytoplankton(〈20$\mu\textrm{m}$) ranged from 43 to 97% in the surface layer. Optimum light intensity(Iopt)was around 300 to 700${\mu}$Es$\^$-1/m$\^$-1/. Surface primary production from 9:00 to 15:00 h was evidently inhibited by strong light intensity beyond the Iopt. Phytoplankton near the base of euphotic zone(30-40m) showed extremely low Iopt suggesting adaptation to a low light environment. Since Iopt represents the history of light experience of phytoplankton at a given depth, the extent of variation in I of phytoplankton at different depth seems to be related to the in tensity of turbulence mixing in the surface mixed layer. From the present study, ammonium excretion by macrozooplankton (〉350$\mu\textrm{m}$) contributes from 3 to 19% of daily total nitrogen requirement by phytoplandton in this area. Calculation of upward flux of nitrate to the surface mixed layer from the lower layer, based on the simple diffusion model, approximates 3% of nitrogen requirement by phytoplankton. However, large portion of nitrogen requirement by phytoplankton remains unexplained in this area. In upwelling area near the coast, adjective flux might be the major source for the nitrogen requirement by phytoplankton. This study suggests that the major nitrogen source for the phytoplankton growth might come from the pelagic regeneration by nano-and micro-sized heterotrophic plandkon. Enhancement of primary production during the passage of the warm Tsushima Current is discussed in relation with nutrient dynamics and hydrlgraphic processes in this area.

• Korean Journal of Ecology and Environment
• /
• v.37 no.4 s.109
• /
• pp.436-447
• /
• 2004

Wetland plants have evolved specialized adaptations to survive in the low-oxygen conditions associated with prolonged flooding. The development of internal gas space by means of aerenchyma is crucial for wetland plants to transport $O_2$ from the atmosphere into the roots and rhizome. The formation of tissue with high porosity depends on the species and environmental condition, which can control the depth of root penetration and the duration of root tolerance in the flooded sediments. The oxygen in the internal gas space of plants can be delivered from the atmosphere to the root and rhizome by both passive molecular diffusion and convective throughflow. The release of $O_2$ from the roots supplies oxygen demand for root respiration, microbial respiration, and chemical oxidation processes and stimulates aerobic decomposition of organic matter. Another essential mechanism of wetland plants is downward water movement across the root zone induced by water uptake. Natural and constructed wetlands sediments have low hydraulic conductivity due to the relatively fine particle sizes in the litter layer and, therefore, negligible water movement. Under such condition, the water uptake by wetland plants creates a water potential difference in the rhizosphere which acts as a driving force to draw water and dissolved solutes into the sediments. A large number of anatomical, morphological and physiological studies have been conducted to investigate the specialized adaptations of wetland plants that enable them to tolerate water saturated environment and to support their biochemical activities. Despite this, there is little knowledge regarding how the combined effects of wetland plants influence the biogeochemistry of wetland sediments. A further investigation of how the Presence of plants and their growth cycle affects the biogeochemistry of sediments will be of particular importance to understand the role of wetland in the ecological environment.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.12 no.1
• /
• pp.35-46
• /
• 2009

In order to investigate spatial and temporal distributional characteristics of major water qualities in the Saemangeum area during the Saemangeum dike construction, salinity, COD, dissolved nutrients(DIN, Silicate) and heavy metals were analyzed from the surface water collected in April, May, August and November 2002. The overall value of Salinity, COD, DIN, and silicate in surface waters were in the range of $13.08{\sim}31.96\;psu$, $0.12{\sim}3.43\;mg/L$, $0.001{\sim}2.638\;mg/L$, and $0.010{\sim}3.181\;mg/L$, respectively. The COD and DIN in each survey showed the highest concentration at the mouth of Mangyeong river estuary(St. 1) where freshwater flow into the Saemangeum area. The concentrations of nutrients were high in the inner part of the Saemangeum dike with low-salinity, and low nutrients in the outer part of the dike with high-salinity, which strongly indicated that concentrations were adjusted by physical mixing. The ranges of dissolved metals and acid-soluble Hg in surface seawater were $0.006{\sim}0.115{\mu}g/L$ for Co, $0.26{\sim}0.114{\mu}g/L$ for Ni, $0.14{\sim}0.93{\mu}g/L$ for Cu, $0.04{\sim}0.53{\mu}g/L$ for Zn, $0.010{\sim}0.043{\mu}g/L$ for Cd, $0.010{\sim}0.795{\mu}g/L$ for Pb, and $0.25{\sim}4.16{\mu}g/L$ for Hg. The highest concentrations of some metals except for Cd were found at the estuary(Sts. 1 or 3). In most cases, a decreasing order of metal concentrations towards open sea(low-salinity$\rightarrow$high-salinity) was observed and showed positive relationship with DIN and silicate caused by land base pollutants input. On the other hand, due to Cd desorption from suspended solids in saline water, dissolved Cd concentrations were high in high-salinity area and low in low-salinity. In November, Co, Zn, Cu and Pb were relatively high in the northern area of the outer-side of Saemangeum, which was only influenced by the Geum river discharge. The concentrations of most dissolved metals of this study were lower than those of the past data in this area, but higher than those in Lena river estuary under the pristine environment.