• 한국습지학회지
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• 제19권4호
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• pp.491-500
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• 2017

하천수량은 하천의 수질, 생태환경보전에 있어 가장 근원적이고 기본적인 사항으로 매우 중요한 요소이다. 본 연구의 목적은 경기도 도심하천의 불투수면적률에 따른 하천수량 변화 원인 및 영향을 분석하여, 경기도 도심하천의 하천수량 확보 방안 및 하천관리 정책에 반영할 있는 자료를 제시하는 것이다. 이를 위해 안양천유역, 탄천유역, 오산천유역을 표본 도심하천으로 선정하고, 불투수면적률(%ISA)에 따른 하천수량 및 수질의 변화와 직 간접적인 하천수 확보방안을 검토하였다. 그 결과를 정리하면 다음과 같다. 안양천유역, 탄천유역, 오산천유역의 불투수면적률은 2014년을 기준으로 약 10년전 보다 각각 5.32%, 6.32%, 7.22% 증가하였으며, 전반적으로 불투수면적률이 증가할수록 유출계수는 증가하는 경향을 보였다. 하천 재이용수량은 탄천유역에서 하천수 확보에 긍정적 효과가 나타났지만 안양천유역과 오산천유역은 하천수 확보 효과가 미흡하였다. 그러나 하천 재이용수량으로 인해 각 하천 수질등급이 개선되는 것으로 나타났다.

• International Journal of Quality Innovation
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• 제9권1호
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• pp.22-40
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• 2008

Unnatural working postures usually cause musculoskeletal problems for workers in work field, especially in traditional industry. Many analysis and survey methodologies have been developed to identify unnatural postures and disorder risks in workplaces. The Ovako Working Posture Analyzing System (OWAS) and Nordic Musculoskeletal Questionnaire (NMQ) are the representative methods and applied widely. This study applied the both tools to investigate the work field of a manufacturing factory of the water heater's case. We divided the manufacturing process into nine workshops, took the pictures of working motions by DV camera and analyzed the postures on OWAS. From the OW AS results, we could identify the risks level of musculoskeletal symptoms as four Action Categories (AC). And from the comparison of OWAS and NMQ results, we could provide the suggestions to improve the working methods and environment. From the results of OWAS, we found that the operators' head/neck and back were above AC3 in some workshops. If the situation continued in long period, the operators might have the risk to get musculoskeletal symptoms. From the investigation of NMQ, we also found that the percentage of aches on neck, shoulders and lower back were higher than other parts of body. The correlation between aches and jobs was more than 75%. So we provided some suggestions to improve: work rotation and adjustment of work surface/height to fit in with Ergonomics. Then the risks of musculoskeletal symptoms would be reduced.

• 상하수도학회지
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• 제29권1호
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• pp.23-31
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• 2015

Aquifer storage transfer and recovery (ASTR) is a type of managed aquifer recharge which entails injecting water into a storage well and recovering it from a different well. It has effects of natural purification when injected water passes through aquifer medium, and can be a good way of supplying water especially in a region with poor surface water quality. This study is about an on-going effort to introduce ASTR as a solution to source water problems in coastal areas. A pilot study is being conducted in the delta of the Nakdong River. A proactive management system is incorporated to ensure the water qulity in the process of drinking water process. The system is based on the Hazard Analysis and Critical Control Point (HACCP) which is a tool originated from the food industry in order to assess hazards and establish control systems for the safety of food product. In this paper, we analyze hazardous events which can occur in the entire water supply system using ASTR as a first step to the incorporation of HACCP to drinking water production process.

• 동아시아식생활학회지
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• 제17권6호
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• pp.883-893
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• 2007

To optimize the preparation process for oven-roasted glutinous rice cake, an experiment was derived using a central mixing composite design to determine the optimal conditions. The addition of flour by soaking time as well as sucrose and water, were the independent variables, with the moisture content, color, sensory, and texture properties of the ovenroasted glutinous rice cakes selected as response variables. For the moisture content, color, sensory, and textural properties, we found significant effects for moisture, lightness, redness, hardness, and cohesiveness in the oven-roasted glutinous rice cakes, and water was one of the most influential factors. The optimal mixing conditions for the highest quality oven-roasted glutinous rice cake, in terms of sensory and textural properties, were 266.0 g of water, 25.4 g of sucrose, and 61.5 minutes of soaking time for the glutinous rice flour. The soaking time was in close to the median, whereas the water and sucrose values were slightly above the median.

• 에너지공학
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• 제26권1호
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• pp.68-75
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• 2017

Global warming affects water supply and water resources throughout the world. In many countries, climate change affects significantly on the fresh water resources. Vietnam is exposed mainly, to landslides and floods triggered by tropical storms and monsoon rains, although storm surge, whirlwind, river bank and coastal line erosion, hail rain. In addition to the prevalent drought, there are many major water challenges, including water availability, stress, scarcity and accessibility, because of poor resource management. Fast growth of urbanization, industrialization and population growth, agricultural activities and climate change cause heavy pressure on water quality. Both domestic and industrial wastewater, as well as storm water shares the same drainage. The common facilities for wastewater treatment are not available. Therefore, wastewater is treated only superficially and then discharged directly into rivers and lakes causing serious pollution of surface water environment. In this paper, we reported the severe water crisis and massive green algal blooms formation in Vietnam rivers and lakes. This is the biggest evidence of climate change variations in Vietnam.

• 한국물환경학회지
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• 제25권6호
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• pp.922-934
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• 2009

The transport of contaminants and spatial variation in a deep reservoir are certainly governed by the thermal structure of the reservoir. There has been continuous efforts to utilize three-dimensional (3D) hydrodynamic and water quality models for supporting reservoir management, but the efforts to validate the models performance using extensive field data were rare. The study was aimed to evaluate a 3D hydrodynamic model, ELCOM, in Daecheong Reservoir for simulating heat fluxes and stratification processes under hydrological years of 2001, 2006, 2008, and to assess the impact of internal wave on the reservoir mixing. The model showed satisfactory performance in simulating the water temperature profiles: the absolute mean errors at R3 (Hoenam) and R4 (Dam) sites were in the range of $1.38{\sim}1.682^{\circ}C$. The evaporative and sensible heat losses through the reservoir surface were maximum during August and January, respectively. The net heat flux ($H_n$) was positive from February to September, while the stratification formed from May and continued until September. Instant vertical mixing was observed in the reservoir during strong wind events at R4, and the model reasonably reproduced the mixing events. A digital low-pass filter and zero crossing method was used to evaluate the potential impact of wind-driven internal wave on the reservoir mixing. The results indicated that most of the wind events occurred in 2001, 2006, 2008 were not enough to develop persistent internal wave and effective mixing in the reservoir. ELCOM is a suitable 3D model for supporting water quality management of the deep and stratified reservoirs.

• Asian-Australasian Journal of Animal Sciences
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• 제12권2호
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• pp.220-225
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• 1999

The environmental conditions in smallholder dairy farms especially the effects of dairy wastes on waters and soil were the main objectives of this investigation. Forty-three dairy farms from an older dairy cooperative (Nongpho Dairy Cooperative, NP) were compared with four dairy fauns from relatively new dairy cooperative (Kamphaengsaen Dairy Cooperative, KS) for the quality parameters of water and soil samples during a 12-month period. Forty-three farms at NP were from three geographical areas and three levels farm crowdedness. The results from this study clearly showed that the waste waters from older dairy barns contained much higher levels of organic and inorganic substances which could create environmental pollution if not properly managed. The differences in waste water qualities due to areas and seasons were not significant, while waste water samples from crowded farms tended to contain higher averages of waste water parameters such as COD and BOD. Highly significant correlations between pairs of waste water parameters indicated that certain parameters can be used without the need for chemical analysis of some other parameters. The qualities of well water on dairy farms as well as water samples from public waterways nearby indicated some contamination of dairy wastes such as manure. Storage and sun-drying of dairy manure on bare soil surface could result in the contamination of underground water and nearby water sources. Some recommendations from this study if implemented can prevent environmental pollution in smallholder dairy farms.

• 한국환경과학회지
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• 제12권8호
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• pp.841-846
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• 2003

The ecosystem model was applied to estimate the regional distribution of the net production(or consumption) of phytoplankton and the net uptake(or regeneration) rate of nutrients in Masan Bay for scenario analysis to find a proper management plan. At the surface level, net production of phytoplankton is 200 mgC/㎡/day at the entrance of the bay, and 400∼1000 mgC/㎡/day at the center of the bay. The inner area of the bay showed more than 2000 mgC/㎡/day. All areas of the bottom level have a net consumption, with the center of the bottom level showing more than 600 mgC/㎡/day. For dissolved inorganic nitrogen, the results showed a net uptake rate of 100∼900 mg/㎡/day at the surface level. It showed that the net regeneration is above 50 mg/㎡/day at the bottom level. For dissolved inorganic phosphorus, the net uptake rate showed 10.0∼80.0 mg/㎡/day at the surface level, and the regeneration rate showed 0∼20.5 mg/㎡/day at the bottom level. Therefore, in order to control the water quality in Masan Bay, it is important to consider the re-supplement of nutrients regenerated in the water column.

• 한국농공학회논문집
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• 제47권1호
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• pp.93-102
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• 2005

A prototype surface flow constructed wetland was built in the upstream area of Sihwa reclaimed tidal lands to improve the water quality of Lake Sihwa by treating severely polluted stream water. In this study, we monitored hydrology, macrophyte (Phragmites communis Trin,) growth, and water quality in the Banwol and Donghwa wetlands to evaluate their performance during the initial period after the completion of wetland construction, The average removal efficiency($\%$) in each wetland was relatively low compared with the performance data from the North America Wetland Treatment System Database (NADB), which mainly includes urban sewage-treatment wetlands. However, the average removal rates per unit area ($g/m^{2}/day$) were 0.72, 0.72 and 0.51 (BOD), 2,04, 2.46 and 0.70 (SS), 0.89, 0.43 and 1.09 (TN) and 0.02, 0.02 and 0.02 (TP) in the Banwol and Donghwa wetlands and NADB, respectively. The overall performance of the Banwol and Donghwa wetlands was within the expected range of the wetland system processes contributing the reduction of the pollutant load to Lake Sihwa during the initial period of wetland operation. Considering the low influent concentration, high hydraulic loading rate, and insufficient macrophyte growth since the wetland was constructed, better performance is expected if an improved operational scheme is adopted.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.374-374
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• 2023

Groundwater is the main source of water on which relies many countries in case of emergency, this is the case of Japan in 2011 after the great Sendai Earthquake. This important resource is found to be heavily influenced by human induced factors such as wetland area reduction. For groundwater sustainable management in perfect cohesion with wetland it is important to understand the relationship between both resources. Wetlands have a strong interaction with both groundwater and surface water, influencing catchment hydrology and water quality. Quantifying groundwater-wetland interactions can help better identify locations for wetlands restoration and/or protection. This study uses observation data from piezometers and wetland to study the qualitative and quantitative aspects of the correlation. Groundwater level, wetland area, chemical, organic and inorganic contaminants are the important parameters used. the results proved that few contaminants in the wetland are found in groundwater and in general the wetland quality does not affect that much groundwater quality. The strong linear relationship found between wetland water level and nearest groundwater level proved that, in term of quantity, groundwater and wetland are strongly correlated. While wetland becoming dry, groundwater level has dropped in the region about 0.52m. The area of wetland was found to be lightly correlated with groundwater level, proving that wetlands dry has contributed to groundwater level declining. This study has showed that whilst rainfall variability contributed to the decline and loss of wetlands, the impacts from landuse changes and groundwater extraction were likely to be significant contributors to the observed losses.