• 한국수산과학회지
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• 제35권4호
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• pp.356-365
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• 2002

One of the most important factors that cause eutrophication is nutrient materials containing nitrogen and phosphorus which stem from excreation of terrestial sources and release from sediment. Therefore, to improve water quality, the reduction of these nutrients loads should be indispensible. At this study, the three-dimensional numerical hydrodynamic and ecosystem model, which was developed by Institute for Resources and Environment of Japan, were applied to analyze the processes affecting the eutrophication. The residual currents, which were obtained by integrating the simulated tidal currents over 1 tidal cycle, showed the presence of a typical counterclockwise eddies between Gyewha and Garyuk island. Density driven currents were generated westward at surface and eastward at the bottom in Saemankeum area where the fresh waters are flowing into, The ecosystem model was calibrated with the data surveyed in the field of the study area in annual average. The simulated results were fairly good coincided with the observed values within relative error of $30\%$. The simulations of DIN and DIP concentrations were performed using ecosystem model under the conditions of $40\~100\%$ pollution load reductions from pollution sources. In study area, concentration of DIN and DIP were reduced to $59\%$ and $28\%$ in case of the $80\%$ reduction of the input loads from fresh water respectively. But pollution loads from sediment had hardly affected DIN and DIP concentration, The $95\%$ input load abatement is necessary to meet the DIN and DIP concentration of second grade of ocean water quality criteria.

• 대한지역사회영양학회지
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• 제19권4호
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• pp.372-385
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• 2014

Objectives: The purpose of this study was to develop web-based self-nutrition management u-Health program for diabetic patients (DMDMG: Diabetes Mellitus Dietary Management Guide) for achieving systematic self-management of diet. Methods: The program consisted of five parts with different contents according to the results of needs assessment. Five major parts were 1) meal management part which contains calorie prescription, meals recording and dietary assessment, 2) prevention of disease part with information of diabetes and assessment of dietary behavior, 3) dietary behavior modification part with an education on dietary behavior modification plan and dietary behavior plan, 4) meal plan containing a training section for meal plan and self constructing part for meal planning by making tables, and 5) information about myself which composed with general and physical information. The system proposed in this study provides nutrients intake results right after input of diet intake, which is possible with simultaneous calculation of input data in the server with 3,495 food and 1,821 meal data base. The nutrients analysis program was evaluated with 26 diabetic patients with two-day 24 hr recall. Results: The differences of nutrients intakes between DMDMG and CANPRO 3.0 ranged from 13.5-16.5%, which was caused by the differences of databases of the two programs. The characteristics of DMDMG were; 1) it can provide an interactive tailored nutrition management, 2) it is a practical tool of diabetes nutritional management, 3) the program gives motivation for the dietary behavior modification. Conclusions: The effectiveness of whole program needs to be conducted, but the program was an innovative tool for self-management of nutrient intakes, diet behaviors, meal management and tailored nutrition education.

• 한국산림과학회지
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• 제110권4호
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• pp.569-576
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• 2021

This study developed an estimation model for litterfall input using the stand parameters (basal area, stand density, mean DBH, and carbon stocks of the aboveground tree biomass) collected from the Korean red pine (Pinus densiflora S. et Z.) stands of seven regions in Gyeongsangnam-do. The mean annual litterfall was 2,779 kg ha^-1 year^-1 for needles, 883 kg ha^-1 year^-1 for miscellaneous, 611 kg ha^-1 year^-1 for broadleaved, 513 kg ha^-1 year^-1 for branches, and 340 kg ha^-1 year^-1 for bark litter. The mean annual total litterfall was 5,051 kg ha^-1 year^-1. Litterfall components were significantly correlated with stand parameters, except for broadleaved litter. A stronger correlation was observed between the carbon stock of the aboveground tree biomass and all the litterfall components compared with the other stand variables. The allometric equations for all the litterfall components were significant (P < 0.05), with the stand parameters accounting for 5%-43% and 8%-42% of the variation in the needle litter and total litterfall, respectively. The results indicated that the annual litterfall inputs of the Korean red pine stands on a regional scale can be effectively estimated by allometric equations using the basal area and carbon stocks of the aboveground tree biomass.

• 한국토양비료학회지
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• 제38권3호
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• pp.164-171
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• 2005

벼농사가 주변 수계의 수질에 미치는 영향을 평가하기 위해 경기도 이천시 부발읍의 광역 논을 대상으로 2002년 5월부터 2003년까지 9월까지 벼 재배기간 동안 논에서 양분물질인 질소와 인의 유입 및 유출부하량을 조사하였다. 재배기간 동안 평균 시비량은 질소가 2002년에 $129.0kg\;ha^{-1}$ 그리고 2003년에 $145.1kg\;ha^{-1}$이었으며, 인은 각각 $56.5kg\;ha^{-1}$와 $55.1kg\;ha^{-1}$로서, 질소 시비량은 2003년에 약간 많았으나 인 시비량은 비슷하였다. 조사기간 동안 물 수지는 2002년에 강우량 888 mm, 관개수량 1,321 mm, 침투수량 1,028 mm, 지표유출량 677 mm, 증발산량은 342 mm이었고, 2003년에 강우량 1,115 mm, 관개수량 1,493 mm, 침투수량 1,147 mm, 지표유출량 865 mm, 증발산량은 276 mm 이었다. 강우량과 지표배출수량은 2002년과 2003년 모두 결정계수($r^2$)가 각각 0.92와 0.81로 선형적인 양의상관으로 나타나 재배기간 중 논에서의 배출수량은 강우량이 증가할수록 선형적으로 증가하였다. 강우, 관개수, 지표 배출수, 침투수 및 작물흡수량의 질소 부하량은 2002년에 각각 9.9, 41.6, 22.1, 5.5, $123.6kg\;ha^{-1}$이었으며, 2003년에는 각각 15.8, 55.4, 17.3, 7.5, $119.1kg\;ha^{-1}$이었다. 강우, 관개수, 지표 배출수, 침투수 및 작물흡수량의 인 부하량은 2002년에 각각 2.1, 13.0, 3.6, 1.8, $64.0kg\;ha^{-1}$이었으며, 2003년에는 각각 1.6, 15.0, 5.0, 1.2, $61.4kg\;ha^{-1}$이었다. 강우량 및 배출수량과 양분물질 배출 부하량과의 관계는 강우량 및 배출수량이 증가할수록 논에서의 양분물질 배출 부하량은 선형적으로 증가하였다. 또한, 재배시기별 질소와 인의 유입 부하량과 유출 부하량 차이는 전 생육기간동안 유입 부하량이 유출 부하량보다 많아 논은 양분물질을 흡수하는 기능을 가지고 있었다.

• 한국환경농학회지
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• 제9권2호
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• pp.133-141
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• 1990

호소(湖沼)의 수질관리 및 예측에 필요한 기초자료로서 농경지로부터의 오염부하량(汚染負荷量)을 제시할 목적으로 1989년 5월 8일부터 9월 30일까지 벼의 생육기간에 정남면 소재 29.3ha의 논에서 질소와 인을 조사 분석한 결과를 요약하면 다음과 같다, 1. 대상지구로 유입된 관개량은 715mm로서 강우량의 영향을 많이 받았다. 침투수량은 318mm로서 관개와 강우로 인한 담수유무(湛水有無)에 따라, 지표유출 수량은 1060mm로서 관개량과 강우량에 따라 월별로 큰 변화를 보였다. 2. 년간 살포된 비료의 양은 질소로서 180kg/ha, 인으로서 46kg/ha이었다. 조사기간동안 관개수에 의한 유입은 TKN이 15kg/ha, TP가 10kg/ha이었는데, 5, 6월에 특히 많은 유입을 보이는 것은 이 시기에 관개량이 많았고 저수지의 준설(浚渫)로인하여 관개수에 질소 및 인이 흡착된 토입자가 포함되어 그 농도가 높았기 때문으로 사료 된다. 3. 지표유출량은 조사기간 동안 TKN이 39kg/ha, TP가 9kg/ha로 나타났다. 침투유출량은 TKN이 7.5kg/ha, TP가 2kg/ha를 보였다. 두 값 모두 5, 6월에 큰 값을 보이는 이유는 관개수에 의한 유입과 시비로 인한 영향으로 판단된다. 4. 하천에서 유하거리(流下距離)에 따른 영양물질 변화는 WS1에서 TKN이 0.31mg/L/km(0.04g/km), TP가 0.01mg/L/km(0.004g/km)의 감소를 보였고 WS2는 TKN이 0.84mg/L/km(0.24g/km), TP가 0.11mg/L/km(0.10g/km)의 감소를 보였다. WS2가 WS1보다 유거연장(流距延長)이 짧지만 더 큰 감소를 나타낸 것은 사행이 더 심하고 하상기복이 커서 유속이 작기 때문인 것으로 사료된다. 5. 농경지로부터 하천이나 호수(湖沼)로 유입되는 오염물질(汚染物質)의 양(量)을 저감하기 위해서는 비료의 사용량을 제한하거나, 배수로(排水路)와 하천에 보 같은 구조물을 설치하여 유속을 줄이므로서 영양물질을 침전시키거나, 영양(營養)물질을 많이 소비하는 식물을 재배하여 자정작용의 기회를 확대시켜야 할 것으로 사료된다.

• 한국해양학회지
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• 제20권2호
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• pp.49-60
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• 1985

영일만의 식물플랑크돈의 분포와 수괴의 수리적 특성과의 상호관계에 관한 연 구가 1983년 12월부터 1984년 7월에 걸쳐 이루어졌다. 식물플랑크톤 현존량의 시간 적 변화는 수괴의 수직적 안정도와 영양염의 공급을 수반한 담수의 유입과 밀접한 관계를 보였다. 우점종의 시간적 동태는 일반적인 천이양상과 일치하였고, 특히 Skeletonema costatum은 매 조사시기마다 우점종으로 나타났다. 식물플랑크톤의 색소량과 개체수는 세포의 크기변화에 따른 차이는 있어도 전반적으로 좋은 상관관 계를 보였다. 다변량분석에 따른 조사해역의 구분은 수괴의 수리적 특성과 식물플 랑크톤의 분포양상과의 상호연관성을 잘 반영하고 있다.

• 상하수도학회지
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• 제26권6호
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• pp.815-823
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• 2012

Non-point source pollutants in down stream of Nakdong river were simulated by SWAT. GIS was utilized to make input data of SWAT such as landuse pattern and soil. Meteorological data of 2007 and 2009 were applied for the calibration and validation of runoff in SWAT. It was difficult to calibrate and validate the runoff and nutrient results since a study area was influenced by the tidal effects. Jindong site was selected to escape from the bias of runoff simulation in the coastal area. $R^2$ values of calibration and validation were 0.8 and 0.79. However, $R^2$ values of water qualities were very low level in comparison to runoff. These resulted from the concentration scale of water qualities such as BOD, T-N and T-P. Additionally, tidal influence could effected on the measurements of nutrients. The simulated annual averages and patterns of BOD, T-N and T-P in SWAT were similar to the measurement data. 80 ~ 96 % of nonpoint source pollutants at Nakbon M site were released from April to August of 2009. The ratio of T-N and T-P from nonpoint source were above 50 % during the rainy season.

• 한국환경농학회지
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• 제19권5호
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• pp.370-374
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• 2000

At this study, the monitoring network of water quality was established in the agricultural watershed an area 14,960 ha of the central southwest of Korea. Loads of nitrogen and phosphorus by agricultural land use were quantified bases on total amounts of stream flow. The land were used as a lowland paddy, an upland and a forest about 12.14 % (1,815 ha), 5.17 % (773 ha) and 80.31 % (12,015 ha) of the area, respectively. For six months, from May 1 to October 31, 1999, the total precipitation was 970 mm and the total amount of stream flow was $80,281,000\;m^3$. In the load of agricultural non-point sources relevant to land use, total-N was 138,413 kg, then ammonia-N 13,362 kg, nitrate-N 124,629 kg, and total-P 157 kg. The loss of nutrient which from application of chemical fertilizer were 38.0% in nitrogen and 0.1% in phosphorus to input chemical fertilizer in the watershed.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.918-921
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• 2006

The short-term variation of sea surface temperature before and after typhoons and increase of chlorophyll a concentration that accompany with the typhoons during summer in the East/Japan Sea were explored by satellite. Four typhoons (NAMTHEUN, MEGI, CHABA and SONGDA) and a typhoon (NABI) passed over the East/Japan Sea in 2004 and 2005, respectively. Decreasing of SST was observed in the every five typhoons, however the magnitude of SST decreasing were various from 1 to $5^{\circ}C$. Chlorophyll a increases were found after the typhoons (0.1-3 ${\mu}g$ $l^{-1})$ except NAMTHEUN, and the area was approximately included in SST decreasing area by the typhoons. It suggests that chlorophyll a increase was caused by nutrient input from subsurface layer by strong mixing. On the other hand, rarely chlorophyll a increase was observed in northern area of polar frontal zone, which is located in $38-41^{\circ}N$, than northern area, and chlorophyll a increase in coastal area was higher (more than 3 times) than offshore area. It might suggest that chlorophyll a increase in the East/Japan Sea is also related with the depth or nitracline depth that affects the amount of nutrients supply to the upper layer by typhoon mixing.

• 한국토양비료학회지
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• 제44권1호
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• pp.78-83
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• 2011

Phosphorus (P) which is required by all living plants and animals is an important input for economic crop and livestock production systems. Phosphorus containing compounds are essential for photosynthesis in plants, for energy transformations and for the activity of some hormones in both plants and animals. Loss of soil P to water can occur in particulate forms of P with eroded surface soil and in soluble forms in runoff, soil interflow, and deep leaching. The excessive losses of P from agricultural systems can degrade water quality of surface waters, resulting in accelerating eutrophication. Thus, P is often the limiting element and its control is of prime importance in reducing the accelerated eutrophication of surface waters. However, reserves of phosphate begin to run out, the impacts are likely be immense in terms of rising food prices, growing food insecurity. This paper reviews underappreciated resource as a key component of fertilizers and one of controversial pollutant in terms agronomy and environment.