• 한국토양비료학회지
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• 제45권1호
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• pp.112-117
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• 2012

The Revised Universal Soil Loss Equation (RUSLE) is a revision of the Universal Soil Loss Equation (USLE). However, changes for each factor of the USLE have been made in RUSLE which can be used to compute soil loss on areas only where significant overland flow occurs. RUSLE which requires standardized methods to satisfy new data requirements estimates soil movement at a particular site by utilizing the same factorial approach employed by the USLE. The rainfall erosivity in the RUSLE expressed through the R-factor to quantify the effect of raindrop impact and to reflect the amount and rate of runoff likely is associated with the rain. Calculating the R-factor value in the RUSLE equation to predict the related soil loss may be possible to analyse the variability of rainfall erosivity with long time-series of concerned rainfall data. However, daily time step models cannot return proper estimates when run on other specific rainfall patters such as storm and daily cumulative precipitation. Therefore, it is desirable that cross-checking is carried out amongst different time-aggregations typical rainfall event may cause error in estimating the potential soil loss in definite conditions.

• 한국토양비료학회지
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• 제43권5호
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• pp.565-571
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• 2010

시설하우스 내 토양의 염류를 제거하기 위한 기존 관수제염의 문제점은 담수 시 염류가 심토층으로 이동하게 되며 심토층으로 이동된 염류는 시설하우스 내 모세관현상으로 다시 표토층으로 용출되어 순환을 하는 것이다. 이를 해결하기 위하여 기존의 관수제염법을 일부 수정한 방법을 개발하였다. 토양을 담수시킨 후 부유물질을 침전시키고 상등액의 일부를 외부로 빼줌으로써 토양 하부로 염류가 이동하지 않도록 하는 방법이다. 이 방법을 통해 심토층으로 염류가 확산이 되지 않았으며 모세관 현상에 의한 염류의 재집적을 방지 할 수 있을 것으로 판단된다. 또한 밖으로 유출되는 상등액에는 질소, 인, 칼리 등 비료성분을 포함하고 있어 비료로 재이용될 수 있을 것으로 판단된다. 소량의 MgO 투여와 30분 침전을 통해 담수의 탁도 성분을 초기 탁도의 95%이상을 침전 시킬 수 있었다. 담수 내에 암모니아와 인을 함유하고 그들의 농도가 줄어든 것으로 보아 일부 struvite 침전이 이루어졌으며 토양 내에서 천천히 용해되어 작물이 이용할 수 있을 것으로 판단된다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.862-866
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• 2005

도시유역의 유출분석을 위하여 국내에서 많이 사용하고 있는 모형들로는 ILLUDAS, SWMM이 대표적이라고 할 수 있다. 그러나 국내의 대부분의 도시하천의 경우 합류식의 배수계통을 가지고 있어, 홍수시에 하수관거용량을 초과하는 우수량은 하천을 통해 배수가 되고 있다. 이러한 배수계통을 갖는 하천에 대하여 대상유역의 배수관망 자료 부족과 Modeling의 어려움으로 인해 도시유출모형이 아닌 HEC-HMS모형과 같은 유역추적법을 통해 유출분석이 이루어지고 있다. 또한 기존 논문에서 제시한 도시유출모형에 하도추적을 결합한 강우-유출 모의는 정확성 결여 및 번거로운 단점이 있다. 따라서 본 논문에서는 보다 안정적인 해석 모형인 MIKE SWMM 모형을 사용하여 과거 침수자료와 DEM 자료 및 수치 배수관망 자료를 통한 유역 및 배수관망 자료를 구축하고 유역에 대해서는 Runoff Block을 사용하고, 하수관거와 본류에 대해서는 Dynamic 방정식을 이용한 Extran Block을 적용하여 유출분석을 실시하고 그 결과를 기존의 방법들과 비교하여 각각의 장단점 및 적용성을 밝히고 개선방향등을 제시하고자 하였다.

• 한국약용작물학회지
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• 제7권3호
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• pp.162-166
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• 1999

1998년 $6{\sim}9$월의 강수량이 1,042mm, 강수일수가 60일이나 되어 배수조건이 나쁜 포장의 밭작물에 습해가 심하게 발생되었던 안동지역에서 습해정도에 따른 식방풍과 지황의 생육특성 및 수량을 농가포장에서 조사하였다. 식방풍은 습해가 심할수륵 지상부보다 지하부의 생육장해가 더 심하였으며, 주근의 신장생장이 비대생장보다 현저하게 억제되었다. 습해 정도별로 ha당 생근수량은 정상생육에 비하여 $21{\sim}80%$ 감소되었다. 지황은 습해 정도별로 고사주율이 52%였으며, 습해에 의하여 근경의 형성 및 발육이 장해를 받아 습해가 심할수록 주당 근경수와 근경의 직경이 크게 감소되었다. 따라서 습해가 심할수록 상품성이 높은 근경의 수량이 현저하게 감소되었으며, 습해 정도별로 ha당 근경의 생체수량은 정상생육에 비하여 $19{\sim}83%$감소되었다.

• Journal of Nutrition and Health
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• 제18권1호
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• pp.29-35
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• 1985

This study was designed to evaluate the effects of tocopherol supplementation on serum $HDL_{2}$ and $HDL_{3}$ subfraction and lipoprotein pattern of young rabbits fed the different levels of dietary polyunsaturated fatty acids. White male rabbits with an average bo요 weight of 90kg were assigned into 4 groups : LP( Low PUFA) ; HP( High PUFA) ; LPT( Tocopheror added to LP), HPT(Tocopherol added to HP) by feeding safflower oil or coconut oil at loft( w/w )in addition to thew diet with or without tocopherol for 4 weeks. HDL-Chol and HDL subfractions were determined by polyanionic precipitation method, and the relative amount of lipoprotein by electrophoresis. Serum total cholesterol and TG wer slightly lowered in the group of high PUFA diet and its effect was more in the case of tocopherol supplemented. HDL-Chol level was reduced in the high PUFA diet with or without tocopherol, but overall, HDL-Chol level was not influenced by tocopherol addition and also no significant change in lipoprotein pattern when tocopherol added to the HP diet. $HDL_{2}$ level was increased in HPT group but not in LPT group when tocopherol was added to each HP and LP group, respectively. $HDL_{3}$ levels of both LP and HP groups were reduced with tocopherol supplement, but the reduction was less in the high PUFA groups so that $HDL_{2}$ : $HDL_{3}$ ratio of HP was rather close to that of LP, but it was increased when tocopherol supplemented to the HP diet. Therefore, high PUFA diet could improve the anti atherogenic factor when tocopherol supplemented.

• 한국농공학회지
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• 제18권3호
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• pp.4184-4194
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• 1976

Located in the southwestern part of Korea, the Yong San Gang river flows generally northeast to southwest, and because of the specific location, topography and climate, the basin area is subject to recurrent drought and flood damages. To eliminate the cause of such damages and ensure an increase in the farm income by means of effective irrigation supply and increased cropping intensity, efforts are being made to speed up implementation of an integrated agricultural development project which would include construction. of an estuary dam and irrigation facilities as well as land development and tidal reclarnation. In formulating a basin development project plan, it is necessary to study a series of long-term runoff data. The catchment area at the proposed estuary damsite is 3,471$\textrm{km}^2$ with the total length of the river channel up to this point reaching 138km. An analysis of runoff in this area was carried out. Rainfall was estimated by the Thiessen Network based on records available from 15 of the rainfall observation stations within the area. Out of the 15 stations, Kwang Ju and Mok Po stations were keeping long-term precipitation records exceeding some 60 years while the others were in possession of only 5-10 years records. The long-term records kept by those stations located in the center of the basin were used as base records and records kept by the remaining stations were supplemented using the coefficient of correlation between the records kept by the base stations and the remainder. The analyses indicate that the average annual rainfall measured at Kwang Ju during 1940-1972 (33 years) amounts to 1,262mm and the areal rainfall amounts to 1,236mm. For the purpose of runoff analysis, 7 observatories, were set up in the middle and lower reaches of the river and periodic measurements made by these stations permitted analysis of water levels and river flows. In particular, the long-term data available from Na Ju station significantly contributed to the analysis. The analysis, made by 4-stage Tank method, shows that the average annual runoff during 1940-1972 amounts to 2,189 million ㎥ at the runoff rate of 51%. As for the amount of monthly runoff, the maximum is 484.2 million ㎥ in July while the minimum is 48.3 million ㎥ in January.

• 한국수산과학회지
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• 제27권3호
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• pp.314-325
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• 1994

Characteristics of climate in the eastern coastal regions of Korean Peninsula were studied using the meteorological and coastal sea surface temperature (SST) data which were compiled from 1961 to 1990. In the winter half year (from October to March), air temperature (AT) and precipitation of the eastern coastal regions were considerably higher than those of the western and inland regions, but relative humidity was $8{\sim}15\%$ lower. AT of coastal regions was closely related to the variation of coastal SST. These characteristics were more noticeable in the eastern coastal areas and in lower latitude regions. Quantitatively, the $1.0^{\circ}C$ variation of coastal SST may have resulted in the $1.0^{\circ}C{\sim}1.5^{\circ}C$ variation for AT in coastal regions. In the same way as temperature, vapor pressure in coastal regions was also influenced by coastal SST. Relative humidity change corresponding to the $1.0^{\circ}C$ variation of coastal SST was $3.7\%{\sim}6.5\%$. Net heat exchange amounts were positive (sea surface gaining energy) in all coastal regions. Sea surface gained net heat from March to September, and lost it from October to February. Variation of AT in coastal regions was also related to the sensible and latent heat exchanges. Sensible and latent heat amount corresponding to the $1.0^{\circ}C$ variation of AT were $10Wm^{-2}$ at Kangnung, and $8Wm^{-2}$ at Pohang and $13Wm^{-2}$ at Pusan.

• 한국환경과학회지
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• 제20권10호
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• pp.1243-1263
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• 2011

This study was carried out to determine marine environments and phytoplankton community in Deukryang Bay during the period of summer in 1987-2010. Water temperature, salinity, pH and dissolved oxygen were shown in much yearly fluctuations. In August, water temperatures in surface and on bottom were the highest, compared with average surface (24.54$^{\circ}C$) and bottom (22.90$^{\circ}C$) water temperature for 18 years in Deukryang Bay. The main reason is assumed to longer duration of sunshine during the period of August. Although the amount of the rainfall in August was the highest, significant impact of marine environment did not show. Most of dissolved inorganic nitrogen and phosphate in Deukryang were lower concentration during summer and N:P ratio also showed below 18 in Redfield. In particular, extreme increasing of N:P ratio in August was occurred by intensive precipitation. Distribution of phytoplankton community was a consistent occurrence for 18 years. The genus of Chaetoceros, Cosinodisucs and Skeletonema were regarded as the represent diatom, whereas the highest occurrence of genus among dinofagellates was Ceratium. It is thought that the relationship between phytoplankton and nutrient has a strong positive signal, although nutrients persist a little concentration and much fluctuations in marine environments were observed. High availability in phytoplankton is contributed to consistently provide the food organism of shellfish. Consequently, recent decreasing production of shellfish and seed are probably associated with higher temperature during the period of summer. However, higher temperature is also occurred ago and after 2000. On the basis of geography, Deukryang Bay had a small mouth and long channel, which is attributed to decreasing genetic diversity. It is assumed that higher temperature and lower genetic diversity have a extreme impact of larvae and shellfish for reproduction in Deukryang. It is necessary to persistently monitor based on water quality and phytoplankton community.

• 대기
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• 제26권4호
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• pp.577-598
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• 2016

Observational and numerical studies have been carried out to understand the cause and development processes of the heavy rainfall over the middle Korean Peninsula during 0300 LST-1500 LST 29 June 2011 (LST = UTC + 0900). The heavy rainfall event occurred as the synoptic-scale ridge extended from Western Pacific Subtropical High (WPSH) was maintained over East Asia. Observational analysis indicates that the heavy rainfall is mainly due to scattered convective systems, formed over the Yellow Sea, traveling northeastward across the middle peninsula without further organization into larger systems during 0300 LST-0800 LST, and mesoscale convective systems (MCSs) over the Yellow Sea, transformed into a squall line, traveling eastward during 0800 LST-1500 LST. Organization of convective systems into MCSs can be found over the area of mesoscale trough and convergence zone in the northern end of the low-level jet (LLJ) after 0600 LST. Both observational and numerical investigations indicate that a strong LLJ extended from the East China Sea to the Yellow Sea plays an essential role for the occurrence of heavy rainfall. The strong LLJ develops in between the WPSH and a pressure trough over eastern China. Numerical experiments indicate that the land-sea contrast of solar heating of surface and latent heating due to convective developments are the major factors for the development of the pressure trough in eastern China. Numerical study has also revealed that the mountainous terrain including the mountain complex in the northern Korean Peninsula contributes to the increase of rainfall amount in the middle part of the peninsula.

• 대기
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• 제26권4호
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• pp.495-508
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• 2016

In order to determine the prediction possibility of heavy rainfall, a variety of analyses was conducted by using three-dimensional data obtained from Korea Local Analysis and Prediction System (KLAPS) re-analysis data. Strong moisture convergence occurring around the time of the heavy rainfall is consistent with the results of previous studies on such continuous production. Heavy rainfall occurred in the cloud system with a thick convective clouds. The moisture convergence, temperature and potential temperature advection showed increase into the heavy rainfall occurrence area. The distribution of integrated liquid water content tended to decrease as rainfall increased and was characterized by accelerated convective instability along with increased buoyant energy. In addition, changes were noted in the various characteristics of instability indices such as K-index (KI), Showalter Stability Index (SSI), and lifted index (LI). The meteorological variables used in the analysis showed clear increases or decreases according to the changes in rainfall amount. These rapid changes as well as the meteorological variables changes are attributed to the surrounding and meteorological conditions. Thus, we verified that heavy rainfall can be predicted according to such increase, decrease, or changes. This study focused on quantitative values and change characteristics of diagnostic variables calculated by using numerical models rather than by focusing on synoptic analysis at the time of the heavy rainfall occurrence, thereby utilizing them as prognostic variables in the study of the predictability of heavy rainfall. These results can contribute to the identification of production and development mechanisms of heavy rainfall and can be used in applied research for prediction of such precipitation. In the analysis of various case studies of heavy rainfall in the future, our study result can be utilized to show the development of the prediction of severe weather.