• 농촌계획
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• 제24권4호
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• pp.99-119
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• 2018

Unit load factor, which is used for the quantification of non-point pollution in watersheds, has the limitation that it does not reflect spatial characteristics of soil, topography and temporal change due to the interannual or seasonal variability of precipitation. Therefore, we developed the method to estimate a watershed-scale non-point pollutant load using seasonal forecast data that forecast changes of precipitation up to 6 months from present time for watershed-scale water quality management. To establish a preemptive countermeasure against non-point pollution sources, it is possible to consider the unstructured management plan which is possible over several months timescale. Notably, it is possible to apply various management methods such as control of sowing and irrigation timing, control of irrigation through water management, and control of fertilizer through fertilization management. In this study, APEX-Paddy model, which can consider the farming method in field scale, was applied to evaluate the applicability of seasonal forecast data. It was confirmed that the rainfall amount during the growing season is an essential factor in the non-point pollution pollutant load. The APEX-Paddy model for quantifying non-point pollution according to various farming methods in paddy fields simulated similarly the annual variation tendency of TN and TP pollutant loads in rice paddies but showed a tendency to underestimate load quantitatively.

• 한국농공학회논문집
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• 제53권1호
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• pp.17-28
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• 2011

This study was performed to ascertain the possibility of securing inflows to reservoir with low ratio of watershed to paddy field areas by outside diversion weir. The case of Maengdong reservoir and Samryong diversion weir was selected. Most of inflows to Maengdong reservoir with watershed area of $7.06\;km^2$ and total storage capacity of $1,269{\times}10^4\;m^3$ are filled with intake water from outside Samryong diversion weir. Only using water storage data in Maengdong reservoir from 1991 to 2009, the range of water intake in Samryong diversion weir to Maengdong reservoir was optimized to 0.135~30 mm/d, from which water intake to Maengdong reservoir was $1,672.9{\times}10^4\;m^3$ (70.1 %) and downstream outflow to Weonnam reservoir was $714.4{\times}10^4\;m^3$ (29.9 %). The parameters of DAWAST model for reservoir inflow were determined to UMAX of 313.8 mm, LMAX 20.3 mm, FC 136.8 mm, CP 0.018, and CE 0.007. Inflows to Maengdong reservoir were $427.1{\times}10^4\;m^3$ (20.3 %) from inside watershed, and $1,672.9{\times}10^4\;m^3$ (79.7 %) from outside. Paddy irrigation water requirements were estimated to $1,549{\times}10^4\;m^3$ on annual average. Operation rule curve was drawn by using daily inflow and irrigation requirement data. By securing the amount of inflow to Maengdong reservoir to about 80 % from outside Samryong diversion weir, water supply capacity for irrigation of $1,549{\times}10^4\;m^3/yr$ was analyzed to be enough. Additional water supplies for instream flow were analyzed to $1,412\;m^3/d$ in normal reservoir operation, $36,000\;m^3/d$ in withdrawal limit operation by operation rule curve from October to March of non irrigation period.

• 한국환경복원기술학회지
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• 제8권1호
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• pp.73-78
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• 2005

본 연구는 실내에서의 관수주기, 토양처리, 배수층에 따른 생육과 생리적 반응을 살펴봄으로 써 실내에서 도깨비고비의 적정 생육환경을 밝히고자 수행하였다. 실험구의 관수주기는 2회/주와 7회/주로 하였으며 각 실험구의 세부처리로서 토양처리와 배수층처리는 배수층-피트모스 : 버미큘라이트 : 펄라이트=1 : 1 : 1(D-PVP), 피트모스 : 버미큘라이트 : 펄라이트=1 : 1 : 1(PVP), 배수층-부엽토 : 마사토=1 : 1(D-SL) 그리고 부엽토 : 마사토=1 : 1(SL)로 각각 처리하였으며 그 결과는 다음과 같다. 1. 실내환경에서 도깨비고비는 주 2회 관수처리보다 주 7회 관수처리에서 지상부의 생육은 촉진되었으나 낙엽수 증가로 인해 실내적응성은 감소될 뿐 아니라 황화되는 현상을 보였다. 2. 토양에 있어서는 마사토 : 부엽토=1 : 1처리가 피트모스 : 버미큘라이트 : 펄라이트=1 : 1 : 1처리보다 생육이 양호한 것으로 나타났으나 낙엽수의 증가로 인해 실내적응성은 감소하였다. 3. 배수층에 유 무에 따른 생육에 있어서는, 관수주기와 토양에 관계없이 배수층이 없을 경우 초장과 소엽장이 촉진되나, 실내적응성, 포자엽수, 신엽수는 배수층이 있을 때 더 높은 것으로 나타났다. 4. 생리적 변화에 있어 광합성률은 관수주기, 배수층, 토양처리에 따라 차이를 보였으며 주 2회 관수처리구에서는 배수층이 있는 피트모스 : 버미큘라이트 : 펄라이트=1 : 1 : 1처리에서 가장 높게, 주 7회 관수처리구에서는 배수층이 없는 마사토 : 부엽토=1 : 1처리에서 가장 낮은 것으로 나타났다.

• 한국토양비료학회지
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• 제19권1호
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• pp.14-20
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• 1986

무우, 배추, 고추 등(等)의 채소작물(作物)에 대(對)한 관수효과(灌水效果)를 구명(究明)하기 위(爲)하여 1979년(年)부터 1983년(年)까지 본량(本良) 사양토(砂壤土)에서 무관수(無灌水), 관수점(灌水點) -3.0bar, -1.0bar, -0.5bar, -0.2bar로 하였을때 토양수분(土壤水分)의 변화양상(變化樣相)과 이에따른 작물(作物)의 양(養) 수분(水分) 흡수(吸收), 증발산량(蒸發散量)과 물이용효율(利用效率) 및 생육양상(生育樣相)과 수량(收量) 등(等)을 조사(調査)한 결과(結果)는 다음과 같다. 1. 무관수시(無灌水時) 동일(同一)한 기상조건하(氣象條件下)에서 배추, 무우, 고추의 순(順)으로 한발(旱魃)을 받는 정도(程度)가 심(甚)하였다. 2. 토양수분함량(土壤水分含量)이 많을수록 봄채소에 있어 토양온도(土壤溫度)의 지나친 상승을 억제시켜 주었다. 3. 관수(灌水)에 의(依)해 토양수분(土壤水分)potential이 높을수록 엽수분함량(葉水分含量) 및 무기양분(無機養分)의 흡수량(吸收量)이 증가(增加)하였다. 4. 토양수분(土壤水分)potential이 높을수록 물소모량(消耗量)은 증가(增加)하였으며, 물소모량(消耗量)이 어느 정도(程度)까지 증가(增加)할수록 물이용효율(利用效率)도 증가(增加)하였으나 그 이상(以上)에서는 감소(減少)하는 경향이었다. 5. 토양수분(土壤水分)potential이 20~30cm 깊이에서 -1.7bar 이하(以下)로 유지될 때 봄배추의 생장량(生長量) 증가(增加)는 거의 없었다. 6. 작물별(作物別) 최대수량(最犬收量)을 나타낸 관수점(灌水點)은 배추 -0.2bar, 무우 -0.5bar, 고추 -0.2~0.5bar 이었으며, 관수(灌水)에 의(依)한 증수효과(增收效果)는 봄배추에서 가장 컸었다. 7. 적정관수(適正灌水) (-0.2~-0.5bar)에 의(依)해 증수(增收)는 물론 품질향상(品質向上)의 효과(效果)가 컸었다.

• 한국환경농학회지
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• 제37권3호
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• pp.197-206
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• 2018

BACKGROUND: The present study aimed to examine the crops capable of growing and adapting to the external environment and various stresses of reclaimed agriculture land for the development of high value-added agricultural utilization technology based on reclaimed land through standardization and empirical study of cultivation environment for cultivating crops. METHODS AND RESULTS: Two crops namely turnips and beets were selected for the salt tolerance test of soil environmental conditions on reclaimed land. Turnip and beet seedlings were planted on the soil collected at the 'Seokmun' reclaimed land. There are five treatments such as non-treatment, 1.0, 2.0 (control), 4.0 and $8.0dS{\cdot}m^{-1}$ of EC. The contents of betacyanin in beet roots was highest in control and decreased with increasing salt concentration. The GSL contents in the turnip roots waswere highest at EC 2.0 and decreased with increasing salt concentration, whereas those in turnip leaves waswere high both in the non-treated control and atthe EC 1.0-treatment. But, tThere was, however, no statistical differences among the treatments. CONCLUSION: The degree of salt tolerance of crops was examined, and the limit EC iswas expected to be $3.0{\sim}4.0dS{\cdot}m^{-1}$ as reported to date. If the soil improvement is performed and irrigation systems are used in the actual reclaimed land, the EC of supplied irrigation will be low, and desalination effecttreatment by the lower EC of the supplied irrigation on the soil will lead to more favorable soil condition of the rhizosphere and cultivation environment offor the crops than those in the port experiment. Therefore, monitoring the salinity, water content and ground water level will enable prediction of the rhizosphere environment, and setting up irrigation management and supplying irrigation will lead to crop cultivation results that are close to normal.

• 한국수자원학회논문집
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• 제46권2호
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• pp.183-193
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• 2013

수자원시스템의 설계공급량을 결정하기 위한 평가지표의 선택은 수자원기술자가 직면한 중요한 문제이다. 대부분 신뢰도, 회복도 그리고 취약도를 대상으로 평가하게 된다. 그러나 각 지표 간에는 중복성이 있고 회복도와 취약도는 용수공급 여건이 나빠져도 개선되는 증감현상이 나타날 수 있다. 실제 적용에서는 이와 같은 문제점을 인지하지 못하고 한번 계산된 추정치로 판단하는 경우가 대부분이다. 이런 현상에 대한 원인은 수자원시스템의 다양한 특성에 의해 나타나고 있는데 수문 및 수요의 계절적 변동성이 대표적이다. 본 연구에서는 우리나라 댐 설계시 일반적으로 적용하고 있는 신뢰도 지표에 추가하여 다기준 적용을 위한 회복도 및 취약도의 적용성을 분석하였다. 분석방법은 계절적 변동성이 큰 농업용수의 구성비율을 기준으로 7개댐을 선정하여 각 지표 간 상관성과 증감현상을 분석하였다. 분석 결과, 연중 일정량을 공급하는 용담댐은 일반적 추세를 보였으나 농업용수를 공급하는 충주, 안동 및 남강댐 등은 회복도와 취약도에서 증감현상이 뚜렷이 나타났다.

• 한국관개배수논문집
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• 제2권1호
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• pp.10-19
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• 1995

Non-point source pollution due to agricultural chemicals is one of the great concerns from the viewpoint of environmental protection. Scientists have been trying to develop best management practices in agriculture in order to decrease the oater pollution

• 원예과학기술지
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• 제33권6호
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• pp.845-853
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• 2015

The objective of this study was to predict the timing of nitrogen (N) demand through analyzing chlorophyll fluorescence (ChlF), soil-plant analysis development (SPAD), and normalized difference vegetation index (NDVI), which are positively correlated with foliar N concentration in star cluster (Pentas lanceolata). The plants were grown in potting soil under optimal conditions for 30 d, followed by weekly irrigation with five concentrations (0, 4, 8, 16, and 24 mM) of N for an additional 30 d. These five N application levels corresponded to leaf N concentrations of 2.62, 3.48, 4.00, 4.23, and 4.69%, respectively. We measured 13 morphological and physiological parameters, as well as the responses of these parameters to various N-fertilizer treatments. The general increases in Dickson's quality index (DQI), above-ground dry weight (DW), total DW, flowering rate, ${\Delta}F/Fm$', and qP in response to treatment with 0 to 8 mM N were similar to those of SPAD, NDVI, and Fv/Fm. Consistent and strong correlations ($R^2$= 0.60 to 0.85) were observed between leaf N concentration (%) and SPAD, NDVI, ${\Delta}F/Fm$', and above-ground DW. Validation of leaf S PAD, NDVI, and ${\Delta}F/Fm$' revealed that these vegetation indices are accurate predictors of leaf N concentration that can be used for non-destructive estimation of the proper timing for N-solution irrigation of P. lanceolata. Moreover, irrigation with 8 mM N-fertilizer i s recommended w hen leaf N concentration, SPAD, NVDI, and ${\Delta}F/Fm$' ratios are reduced from their saturation values of 4.00, 50.68, 0.64, and 0.137%, respectively.

• 한국농공학회논문집
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• 제49권2호
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• pp.99-108
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• 2007

The purpose of this study was to investigate characteristics of concentrations of pollutants such as TN (Total Nitrogen), TP (Total Phosphorus) and COD (Chemical Oxygen Demand) in outflow from a nonpoint source dominated watershed ($6.7km^2$). Regular flow measurement and water sampling were taken at five-day intervals during two years (February 2002 to January 2004) in the Ingyeong River, a tributary of the Han River. The mean concentrations of pollutants during rainy days were significantly (p<0.05) higher than those during dry days. For dry days, the flow-weighted mean concentration (0.06 mg/L) of TP during paddy irrigation periods were higher than that (0.02 mg/L) during non-irrigation periods. The seasonal mean concentration of TN was highest in spring likely due to nitrogen fertilization, but those of TP and COD were highest in summer due to particulate phosphorus and sediment-associated organic matter caused by increased discharge. The pollutant concentrations significantly increased with discharge, suggesting that the measures to reduce the increase in the concentrations during storms are needed to control nonpoint source pollution.

• 한국농공학회논문집
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• 제57권6호
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• pp.163-171
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• 2015

This study aimed to establish a field observation system for monitoring tempo-spatially precise changes of groundwater level and to analyze the impact of rainfall and irrigation practices on groundwater changes in paddy regions. The monitoring system comprising of all nine groundwater observation wells and four ponding depth sensors was installed in a part of paddy regions benefited from Gosam reservoir, Ansung-si. The result of grundwater level change during the irrigation period in 2002 was averagely 0.51 m higher than that during the non-irrigation period. In particular between March before puddling and June after transplanting, there was maximum 1.23 m rise in groundwater level. On the other hand, concerning the change in ponding depth, groundwater level changed similarly, and hourly rainfall was revealed to have better correlation with 24-hour delayed hourly groundwater level than with the corresponding groundwater level. Eventually, this study could be referenced for further studies to set up a more comprehensive and sustainable monitoring system of groundwater conditions.