• 한국환경과학회지
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• 제23권2호
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• pp.261-274
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• 2014

This work investigates the relationship between the sea breeze circulation and ozone concentrations during cold water events in the southeastern coastal area of the Korean Peninsula, where coastal upwelling frequently occur. This analysis was performed based on the classification of two categories, such as cold water and non-cold water events, over the period of 2000-2009. The low air temperature ($0.5^{\circ}C$), low SST ($5^{\circ}C$) and the wind direction(southerly) are the features of the cold water events in the Southeastern coastal area. Moreover, ozone concentrations in the cases of the sea breeze circulation and cold water events were significantly lower (below 30 ppb) than those (70~100 ppb) in the non-clod water events, because of the low air temperature ($10{\sim}20^{\circ}C$) and high wind speed (3~5 m/s) around the southeastern coastal area.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2004년도 추계학술발표회
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• pp.123-127
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• 2004

It is known that cold water appears and fog frequently forms in the southwest coastal waters of Korea in summer. The authors investigate the time and place. of cold water existence, and also whether the cold water affects the occurrence of fog formation. As a result, cold water begins to appear around Daeheugsando at the early summer. It gets colder with times and cold water area moves toward southwest of Jindo in mid-summer, then disappears in this area around mid-Oct. Fog mostly forms in April through August and most frequently occurs at Chukdo(Jindo) where sea surface temperature shows lower than that at the adjacent area. Accordingly it is taken that the cold water is considerably contributed to form the dense and frequent fog around Jindo area.

• 한국물환경학회지
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• 제24권3호
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• pp.333-339
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• 2008

This study was carried out to assay the relationships between empirical factors and water quality in 23 agricultural reservoirs. Based on the trophic state index (TSI) deviation analysis, phosphorus in type II and III was the primary limiting factor on algal growth. BOD, COD, TP and chl.a concentration in type III reservoirs showed higher concentration than those of other types, while SS and TN concentration was no noticeable difference among three types. Characteristics of type III reservoirs showed large reservoir surface and drainage area, large surface area to volume (SAV) ratio, small drainage area to reservoir area (DA/RA) ratio, relatively old age, large paddy field and upland field to drainage area ratio (Mean 17.4%) and high generation and discharge loads compared to other types of reservoirs. In type I and II reservoirs, trends of BOD, TN, TP concentration in water column, were similar to those of the discharge load of pollutants. Although type II reservoirs generally showed low phosphorus discharge loads compared to type I reservoirs, TP and chl.a concentration in water column was greater than that of type I. Characteristics of type II reservoirs showed relatively large SAV ratio and old age compared to type I reservoirs and was similar to those of type III including eutrophic reservoirs.

• 해양환경안전학회지
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• 제18권1호
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• pp.15-24
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• 2012

동해연안의 수질특성 및 상태를 파악하기 위하여 2004년부터 2010년까지의 국가해양환경측정망 조사결과를 이용하여 수질인자의 거동을 분석하였다. 본 연구에서는 통계적 방법을 이용한 수질인자간의 상관관계 및 주성분 분석을 통하여 해역별 수질환경 특성을 파악하였으며, OECD의 부영양화 기준과 부영양도, 그리고 유기오염도 지수의 산정으로 해역별 오염상태를 평가하였다. 수질인자간의 주성분 분석에서 동해연안은 클로로필 a와 염분이 주요인자로 설명되는 2개의 요인으로 구분되었다. 해역별로는 죽변을 경계로 남부와 중부로 분류되었으며, 동해 중부 해역에서는 죽변, 그리고 남부해역에서는 감포연안이 별도로 분류되었다. 동해연안의 영양상태는 Oligotrophic~Mesotrophic 수준으로 구분되었으며, 부영양화도는 1 이하로 평가되었다. 유기오염지수는 동해연안 전 해역에서 양호한 수질상태로서 평가되었다.

• 수산경영론집
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• 제42권3호
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• pp.79-93
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• 2011

Water temperature of Oliver flounder farm affects Oliver flounder growth and mortality rate. In laboratory experimental tanks, optimal water temperature was $22.5^{\circ}C$($21{\sim}24^{\circ}C$) and cultivatable water temperature was $12{\sim}28^{\circ}C$. The purpose of this study is to identify applicable and useful water temperature of Oliver flounder farm in case of actual farming. The data applied in the analysis was collected from Jeju island. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows : First, growth rate on the Oliver flounder culture farms was related to mean of water temperature, variation of water temperature and low water temperature. Second, survival rate on the Oliver flounder culture farms was related to mean of water temperature. In case of including Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, survival rate strongly related to mean of water temperature, variation of water temperature, cultivating capability and stocking density. Third, production weight per $m^2$ of water surface area was strongly related to mean of water temperature, low water temperature and cultivating capability. Growth rate and survival rate was analyzed into mediate variable character.

• 한국농공학회논문집
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• 제48권2호
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• pp.13-23
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• 2006

In Korea, upland irrigation generally depends on the ground water or natural rainfall since irrigation water supplied from dams is mainly used for paddy irrigation, and only limited amount of irrigation water is supplied to the upland area. For the stable security of upland irrigation water, storage level of irrigation dams was simulated by the periods. A year was divided into 4 periods considering the irrigation characteristics. Through the periodical management of storage level, water utilization efficiency in irrigation dams could be enhanced and it makes available to secure extra available water from existing dams without new development of water resources. Two study areas, Seongju and Donghwa dam, were selected for this study. Runoff from the watersheds was simulated by the modified tank model and the irrigation water to upland crops was calculated by the Penman-Monteith method. The analyzed results showed that relatively sufficient extra available water could be secured for the main upland crops in Seongju area. In case of Donghwa area, water supply to non-irrigated upland was possible in normal years but extra water was necessary in drought years such as 1998 and 2001.

• 한국환경보건학회지
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• 제23권3호
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• pp.56-65
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• 1997

Chemical analysis, statistical analysis and geochemical study were carried out to investigate the influence of the geology on the chemical characferistics of the mineral water in Taegu area. A simple comparision between the chemical components of the mineral water and their bedrocks indicates that the bedrock types in the catchmerit area control the chemical characteristics of the surface water. However more objective evidences for the mineral water-bedrock relationship come from the statistical analyses(cluster analysis and factor analysis). The results of the statistical analyses suggest that the bedrock type factor explains the data variation seven times as much as pollution does, which evidently indicates that the bedrock in the study area mainly control the mineral water chemistries. The results of comparision of the statistical analyses results with the mineral weathering reactions and mineral stability diagrams can be summarized as follows: 1. Plagioclase weathering to kaolinite provides SiO$_2$ , Ca$^{2+}$ and Na$^+$, and muscovite weathering to kaolinite provides K$^+$, and amphibole and mica minerals weathering to kaolinite provides F to the mineral water. Most of Ca$^{2+}$ and Mg$^{2+}$ in the mineral water are the products of carbonate mineral dissolution. SO$_4^{2-}$ may be the byproduct of sulfide oxidation. 2. The weatering of silicate mineral produces Ca-rich smectite and kaolinite, but Ca-rich smectite is unstable and will be transformed to more stable kaolinite because of the continuous dilution of the mineral water by precipitation. By Hashimoto's Mineral Balance Index, S-10 and S-12 mineral spring water were evaluated tasty and healthy water, S-9 and S-11 mineral spring water were evaluated tasty water and S-7, S-8 and S-13 mineral spring water were evaluated healthy water.

• 한국지리정보학회지
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• 제15권1호
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• pp.172-183
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• 2012

2011년 태국 짜오프라야 강 유역에서 발생한 홍수에 의해 많은 피해가 발생했다. 본 연구에서는 홍수범람시 시공간적 침수상황이 파악 가능한 Terra MODIS 영상을 이용하여 태국 짜오프라야 강 유역의 홍수에 의한 침수지역을 추정하였다. 2011년 7월 29일에서 2012년 1월 9일까지의 500m 해상도인 MODIS product MOD09 8일 합성 영상을 수집하고 식생지수(EVI), 지표수분지수(LSWI)와 DVEL지수(식생지수와 지표수분지수의 차이)를 이용하여 홍수범람 지역과 수역관련 지역의 탐지 기법을 제시하였다. 본 연구의 결과는 홍수 범람지역의 자료를 정보화하고 그 결과를 정량적으로 제시하는 방법으로 활용될 수 있으며, MODIS 자료의 이용은 시공간적 하천 홍수범람지역 탐지의 가능성을 알 수 있었다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.1-7
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• 1998

To investigate the water balance in a paddy rice field with the pumping station for irrigation water supply, flow measurements and analysis on various components of water balance were carried out. The investigated area is 103.7 ha, and the irrigation water was supplied for 102 days during the total irrigation period starting from June 1. It was found that the consumption rate was increased as the growing stage was progressed. The variation of evapotranspiration rate was shown same tendency as the consumption rate, while no apparent tendency was found in infiltration rate upon different growing stages. And the ground water input to the area was predominant during the early stage of growing period, while ground water output from the study area was predominant at the end of the growing stage. The range of return flow rate, the ratio of total outflow to total inflow in every decad, was 57.6 to 85.7%. These values are slightly higher than reported values from the other investigation projects.

• 환경위생공학
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• 제13권3호
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• pp.128-132
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• 1998

In this study, water quality characteristics of lakes in the Seosan area are analyzed. Components water quality were analysed at 10 sampled points in each lakes, and the results were evaluated for seasonal variation. It was found that water quality was over II~III class. Most of lakes in the Seosan area which implies that are suitable as the maintenance water. The concenturation of T-N, T-P was observed IV~V class during all seasons. Particularly, T-N concenturation peaks in spring, while was lowered in other seasons. In the lake, high concenturation of T-N, T-P bring about Eutrophication when algae was growth causing various physico-chemical changes in the water. It is suggested that the water quality management strategies need to be applied for each lake.