• 생태와환경
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• 제43권2호
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• pp.199-211
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• 2010

The objectives for this study were to evaluate spatial and temporal characteristics of water quality, based on long-term water quality monitoring data during 1993~2008. We found that physico-chemical and ecological conditions in the Daecheong Reservoir (DR) were modified by the construction of upper dam (i.e., Yongdam Reservoir). total phosphorus (TP), Secchi depth (SD), and chlorophyll-a (CHL) in the DR showed significant longitudinal decreases along the headwater-to-the downlake, indicating a large spatial variation, and this gradient was more intensified during the high-flow season (monsoon). Nutrient-rich water containing high nitrogen and phosphorus in the monsoon season (July~August) passed through the reservoir as a density current in the metalimnetic depth, and also high suspended solids increased in the metalimnetic depth, especially during the monsoon. According to the deviation analysis of Trophic State Index (TSI), >50% of TSI (CHL)-TSI (SD) and TSI (CHL)-TSI (TP) values were negatives, so that inorganic suspended solids (non-votatile solids) influenced the underwater light regime against phytoplankton growth. Also, ratios of CHL:TP after the dam construction evidently increased, compared to the values before the upper dam constructions, indicating a greater yield of phytoplankton in the unit phosphorus. Overall data showed that ecological and functional changes in Daecheong Reservoir occurred after the construction of upper dam (Yongdam Reservoir).

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.81-84
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• 2007

Data for occurrence of hail over Korean Peninsula for the period 1961-2005 are obtained from the Korea Meteorological Administration (KMA). According to the average occurrences during each season in Korea Peninsular, hail days are almost distributed uniformly in the spring, fall and winter, except the summer and have averages of 5 days for each season. Analysis of regional occurrence of hail shows that inland of Korea Peninsular is vulnerable to hail in the spring and summer and the islands of Ullung, Baegryeong and Cheju and the coastal regions vulnerable in the fall and winter. It can be postulated that these seasonal patterns of hail is affected by the Monsoon effect.

• 한국항해학회지
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• 제11권1호
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• pp.107-144
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• 1987

In cold season, ice accretion on ship, drift ice, NW winter monsoon, developed extratropical cyclones and associated cold fronts, in warm season, tropical cyclones and dense sea fogs, are encountered very frequently in the North Pacific, especially in the northwest part of it. The two areas, namely, the northwest part of the North Pacific and Burmuda Triangle in the North Atlantic are generally known as most dangerous areas in the world because its high incidence of sea cascualities. In recent years, the small fisherboats operating in the northern seas were frequently sunk in a group as they encountered ice accretion or drift ice. And ocean going vessels were also sunk frequently due to strong winds and very high seas in winter monsoon or developed cyclones and cold fronts. The purpose of this paper is to analyze the real state of heavy weather conditions such as ice accretion on ship drift, ice, typhoons and sea fogs, and also to analyse the effect of these heavy weather phenomena on the vessels at sea, thus helping mariners operate in such heavy weather conditions.

• Environmental Engineering Research
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• 제14권1호
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• pp.13-18
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• 2009

In this study, specific pollutant releases during the Asian monsoon season were estimated and the information was applied to the non-point pollutant sources management from two forested watersheds of the Soyang Lake. The two watersheds are part of the 2,703 km2 Soyang Lake watershed in the northern region of the Han River. The outlets of the two watersheds were respectively analyzed for continuous water quality concentration and for discharge during various single rainfall events. Statistical power function methods are utilized to compare stream discharge and pollutant flux release during the study period. Based on the monitoring data during the study period, the specific load flux method using simulated discharge was conducted and validated in the two watersheds. The model predictions corresponded well with the measured and calculated pollutant releases. The modeling approach taken in this study was found to be applicable for the two forested watersheds.

• 한국지구과학회지
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• 제30권1호
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• pp.58-68
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• 2009

몬순 기간에 구름의 복사 강제력의 영향을 파악하기 위하여 1998년 4월부터 9월까지 International Satellite Cloud Climatology Project (ISCCP) 구름자료와 GEWEX Asian Monsoon Experiment (GAME) 재분석 자료를 입력 자료로 복사 모델을 수행하여 3차원의 장파 복사 플럭스를 구하였다. 구름에 의한 대기 복사 가열은 구름을 포함한 평균 대기와 맑은 대기에서의 복사 가열율의 차이를 이용하여 계산하였다 구름에 의한 복사 가열율이 아시아 몬순에 미치는 영향을 중점적으로 살펴보았다. 구름에 의한 복사 가열은 인도양에서 최대를 티벳 고원에서 최소를 나타내어, 남북으로 차등 가열의 경도를 나타내었다. 이러한 차등 가열이 대기 순환의 최대 원인임을 고려해볼 때, 인도양과 티벳 고원에서의 구름에 의한 차등 가열의 경도는 해들리 타입의 남북 몬순 순환을 강화시키고 있다. 또한 운정에서의 가열, 운저에서의 냉각의 형태로 나타나는 구름의 복사 가열 분포는, 대기의 불안정성을 높여서 몬순 순환을 증대시킬 수 있는 역할을 하고 있다.

• 한국물환경학회지
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• 제25권6호
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• pp.840-848
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• 2009

Spatial and temporal distributions of POC and DOC were surveyed in the North Han River system, Korea The proportion of algal cells was calculated in four reservoirs (Lakes Soyang, Paro, Chunchon, and Uiam). Monthly average DOC concentrations ranged from 1.5 to 2.3 mg C/L, and POC showed larger variation than DOC (range 0.3 to 1.9 mg C/L). The average proportion of POC in TOC was higher than those of typical natural lakes. Due to the influence of the Asian summer monsoon, the seasonal variation in POC concentration depended on heavy rain events occurring during the summer. POC concentrations increased during the summer monsoon season due to turbid storm runoff laden with debris, while DOC concentrations did not increase. The highest POC concentrations were observed in Lake Soyang in 2006 when a severe rain event occurred. In two deep stratified reservoirs (Lake Soyang and Paro) storm runoffs formed an intermediate turbidity layer with high POC and chlorophyll concentrations which is thought to originate from terrestrial debris and periphyton transported by inflowing streams. The proportion of algal cells in total POC was much lower than for most natural lakes, and it varied with season; low in the monsoon season and high in dry seasons with algal blooms. An analysis of POC concentration and chlorophyll a concentration showed that the ratio of POC/Chl.a varied from 24 to 80.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.197-200
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• 1994

The study was conducted in the Bangladesh Agricultural University campus, Mymensingh, from July 1988 to June 1990. Five grazing fields consisting of five different vegetations were selected for this study. The specimen were collected from this study. The specimen were collected from the grazing fields by dragging method. The results revealed that two species of ticks namely Boophilus microplus and Haemaphysalis bispinosa were collected from five different vegetation. The highest incidence of both B. microplus and H. bispinosa were recorded during winter season and lowest in Monsoon for the year of 1988-89 and 1989-90. These two species were significantly occurred in Winter followed by Monsoon and Autumn.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권7호
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• pp.12-17
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• 2013

Heavy metal contamination of soil and water from industrial sources remains a worldwide environmental concern. Concentrations of toxic metals were measured in soil from banks of the Han and Anyang rivers. Pre-monsoon samples contained the highest heavy metal concentrations (Cu > As > Pb > Cd > $Cr^{6+}$; up to 57.80, 38.23, 25.43, 2.21, 0.32 mg/kg, respectively), but concentrations decreased at all sites during the monsoon and post-monsoon seasons. Higher heavy metal concentrations in pre-monsoon samples may be attributed to dust pollution, especially from roads near the river. A gradual reduction in heavy metal concentrations during the rainy season may be due to washing out. The high concentration of metals could cause health problems, especially in residential areas.

• 한국수자원학회논문집
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• 제53권9호
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• pp.647-660
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• 2020

본 연구에서는 아시아 몬순특성을 고려한 전지구모형(General Circulation model, GCM) 선정방법을 개발하고 방법의 적정성을 평가하였다. 몬순기후와 연관된 12개의 기후변수를 선정하였으며, GCM의 과거 기후재현성을 기준으로 모의성능 평가 매트릭스 및 평가체계를 구성하였다. 19개 GCM으로부터 아시아 몬순지역 및 과거(1976 ~ 2005년) 몬순기간에 대한 12개 기후변수를 관측자료와 비교하여 GCM의 기후모의 성능을 평가하였다. GCM의 평가순위 및 강수량 모의성능을 고려하여 적정 5개 GCM (NorESM1-M, bcc-csm1-1-m, CNRM-CM5, CMCC-CMS, CanESM2)을 선정하였다. 과거 몬순계절 및 월 평균 기후에 대하여 선정된 GCM의 기후재현성을 검증하였다. 선정된 5개 GCM은 12개 기후변수에 대한 아시아 지역의 관측 기후특성을 잘 재현하였으며, 전체 GCM을 사용하는 경우에 비해 모의값과 관측값 간의 오차를 줄일 수 있는 것으로 확인되었다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1430-1432
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• 2003

Agricultural areas in the north region of Bangladesh suffer from water shortages during the dry season as well as dry spells in the monsoon period. The Teesta Barrage was constructed in 1990 to provide supplemental irrigation water during the monsoon period. After completion of the project high yielding variety of crops were introduced more in the project area. Due to this reason unforeseen needs of irrigation water during the dry season has emerged. This study reviews the current irrigation status and related constraints to a full development of the project and provides suggestions for future improvement of the project. Also suggested is to apply remote sensing technique for the management of the system as a whole. Use of remote sensing technique for the management of irrigation water resources is a new approach in Bangladesh. Application of such a powerful tool will provide better management options for large-scale irrigation projects in the country.