논지대 수계환경에서 농약의 노출위험도 분석

정상옥 ( Chung Sang-ok ),박기중 ( Park Ki-jung ) 한국농공학회 2007 한국농공학회 학술대회초록집 Vol.2007 No.-

Exposure risk assessment of pesticide molinate in rice paddy areas was performed to see the effects of various water and pesticide management scenarios and then best management practices were proposed to prevent adverse effects on populations. The results of the RICEWQ model simulation from the previous studies were analyzed. The pesticide risk for aquatic organisms is evaluated by the ratio of the predicted environmental concentration (PEC) and the predicted no-effect concentration (PNEC). To assess the exposure risk to the aquatic organisms, predicted molinate concentrations were grouped into four risk classes. The no risk concentration range is lower than 0.002 mg/L, the low is from 0.002 mg/L to 0.01 mg/L, the moderate is from 0.01 mg/L to 0.1 mg/L, and the high is above 0.1 mg/L. The critical values for each category were calculated from the toxicity endpoint value (median lethal concentration, LC50) divided by the assessment factor (AF). The results showed that the very shallow ponding depth in rice paddies showed lower pesticide exposure risk than the deep ponding depth, and the higher application rate showed greater exposure risk to the aquatic organisms. The results of this study can be used for the non-point source pollution control and environmental policy making regarding pesticides.

CCA를 통한 한국 호소 연구 방법론 탐색

정상옥 ( Sang Ok Chung ),전형주 ( Hyoung Joo Jeon ),홍관의 ( Kwan Eui Hong ),김종화 ( Jong Hwa Kim ),박영석 ( Young Seuk Park ) 한국환경생태학회 2006 한국환경생태학회지 Vol.20 No.4

부분적(部分的)인 멀칭이 토양수분(土壤水分)의 이동에 미치는 영향(影響)

정상옥 ( Chung Sang Ok ) 한국농공학회 1990 韓國農工學會誌 : 전원과 자원 Vol.32 No.2

Soil surface mulch cover in upland crop field affects soil heat and moisture movement significantly. The mulch cover decreases not only surface evaporation but also soil loss from surface runoff. A numerical model using alternating direction implicit(ADI) finite difference scheme is developed to study the effects of mulch cover on soil moisture flow. To study two-dimensional soil moisture flow with partial surface mulch, the change of soil water content is observed by tensiometers at an experimental plot with chopped corn crop residue mulch cover. The model is tested using the field data, then is used to predict soil surface energy partitioning and soil moisture movement. The model can analyze the effects of mulch cover on soil moisture flow satisfactorily. The mulch cover reduced water content variation underneath and the soil surface evaporation. The partial surface mulch cover induced horizontal water flow near the soil surface. The present model can be applied successfully in soil science and groundwater hydrology, and also can be extended to include crops.

용수절약형 논관개 기법

정상옥 ( Chung Sang Ok ),안태홍 ( Ahn Tae Hong ) 한국농공학회 2000 한국농공학회 학술대회초록집 Vol.2000 No.-

A field study was performed to investigate the effect of water saving irrigation method on water use efficiency and rice yield. The field plot was 40a (40 × 100m) in size and located at Buryangmyun, Kimjae city, Chonbuk province. Field measurements were made during the growing seasons, May to September of the year 1998 and 1990. Irrigation water volume, drainage water volume, rainfall and ponding depth were measured. Irrigation water management practice employed was such that to keep the ponding depth about 3 to 4cm by intermittent irrigation with drying the soil surface until hair cracks emerge before the next irrigation. The amounts of water volume irrigated and drained were measured by pipe flow meter and ponding depth was observed by using a partly buried 120mm diameter PVC pipe. The results showed that the irrigation water depths, the rainfalls, and the drainage depths were 379mm, 458mm, and 448mm in 1988, and 274mm, 819mm, and 736mm in 1990, respectively. The average yield was 590kg per 10a. The water saving irrigation method saved irrigation water by about 20% with higher yield compared with the traditional method.

논에서의 농약의 노출 위해성 평가

정상옥 ( Chung Sang-ok ),박기중 ( Park Ki-jung ) 한국농공학회 2006 한국농공학회 학술대회초록집 Vol.2006 No.-

In order to assess the environmental risk of pesticides, information is usually required on the likelihood of exposure of organisms to the constituents of pesticides, expressed as a predicted environmental concentrations and the likely effects of the constituents of pesticides on aquatic and terrestrial organisms, expressed as a predicted no-effect concentrations. The objectives of this study were; (1) to verify the pesticide fate model used in paddy fields; (2) to critically evaluate the applicability for the calibrated model; (3) to propose the best management practices (BMPs) for water and pesticide management methods. The RICEWQ model was successfully calibrated against field data in poinding depth for paddy field. The results of this study can be used as a basic information for assessing the environmental risk of pesticides.

논 관개용수 수온상승 방법의 검토

정상옥 ( Sang-ok Chung ) 한국농공학회 2011 한국농공학회 학술대회초록집 Vol.2011 No.-

다목적 댐 또는 용수전용 댐으로부터 농업용수를 공급할 때 표층수 취수를 하지 않는 경우 낮은 수온으로 인하여 하류 논에서 냉수피해를 입을 수 있다. 이에 대한 대책으로 수온상승 시설을 설치하거나 다른 대책을 세워야 한다. 본 고에서는 우리나리의 기존 온수시설인 소양강 댐 하류의 우두 온수지, 충주댐 하류의 용교 온수로 및 온수지, 주암조절지 댐 하류의 온수지 현황과 수온상승 효과를 소개하였다. 또한 용수전용 댐 (운문댐, 영천댐)은 농업용수는 물론 상수원수를 공급하기 때문에 수질 문제로 하층수를 취수하고 있으며 따라서 하류 농지에서 냉수피해를 입어 오고 있다. 운문댐 및 영천댐 하류의 냉수피해를 소개하고 이에 적정하게 대처할 수 있는 방안들을 소개하였다. 운문댐에서는 수심별 수온 측정 자료로부터 표수층의 깊이를 산정하여 표층수 취수나 온수지 대용의 보로 부터의 취수를 건의한 바 있다. 운문댐관리단에서는 수온 상승 방법으로 흙 수로를 콘크리트 수로로 개수하였다. 영천댐에서는 수심별 수온 측정 자료로부터 표수층의 깊이를 조사하고 댐 하류에 설치된 보의 상류지점과 농업용수 취수문 지점의 수심별 수온을 관측하여 수심별 수온분포를 조사하였다. 본 연구에서 검토한 결과 영천댐 하류의 온수대책으로는 댐 표층수 취수 (취수탑의 상부 취수공 취수 또는 취수 pontoon 이용)를 하는 방안을 제시하였으나 상수원수 취수와의 상충되는 문제를 해결하여야 할 것이다. 그 외에 보 상류 농업용수 취수문을 하층수를 취수하는 승강식 수문 (lift gate)이 아닌 표층으로부터 취수할 수 있는 전도식 수문 (flap gate)이나 드럼 수문 (drum gate)을 설치하는 것도 한 방법으로 제시하였다. 또한 취수구의 위치를 최대한 하류측인 보 가까이로 옮겨서 댐 방류수가 취수구까지 오는 사이에 약간의 수온상승을 기대할 수 있다. 그러나 이 두 가지 방법으로는 큰 효과는 얻기 어려울 것이다. 댐의 표층수 취수와 함께 가장 효과적인 방법인 온수지 건설은 적당한 부지 선정의 어려움과 경제성를 고려하면 채택하기 어려운 대안이다. 농민들의 자발적인 동참으로 효율적인 물관리를 통한 냉수피해 저감방안이 좋은 대안이라고 판단된다.

고해상도 기후예측자료를 이용한 우리나라 논 관개용수량 추정

정상옥 ( Chung Sang-ok ) 한국농공학회 2009 한국농공학회 학술대회초록집 Vol.2009 No.-

우리나라의 장래 기후변화가 논 용수량에 미치는 영향을 분석하였다. 기상연구소의 SRES A2 시나리오에 대한 가상자료와 기상관측소에서 관측한 기준년도 (1971-2000)에 대한 관측 자료를 이용하였다. 기상여구소가 전지구 기후모형인 ECHO-G 모형 출력값을 고해상도 (27 x 27 km)인 MM5 지역기후모형을 이용하여 역학적으로 상세화한 값을 이용하였다. 벼의 관개 요구량의 지역적 변동을 도시 하는 데는 GIS를 이용하였다. 공간적으로는 우리나라 벼 재배지역 전부를 포한하고 시간적으로는 30년간씩 평균한 2020s (2010-2039), 2050s (2040-2069) 및 2080s (2070-2099)에 대하여 분석하였다. 분석결과 벼 생육기간의 평균기온은 기준년도 보다 1.5℃ (2020s), 3.3℃ (2050s) 및 5.3℃ (2080s) 상승할 것으로 예측되었다. 벼생육기간의 평균 강우량은 0.1 % (2020s) 4.9 % (2050s) 및 19.3 % (2080s) 상승할 것으로 예측되었다. 작부체계와 영농방식이 변하지 않는다고 가정하면 논 관개요구량은 2.8 % (2020s) 4.9 % (2050s) 및 4.5% (2080s) 증가할 것으로 예측되었다. 벼 관개요구량의 공간적 및 시간적 변동이 큰 것으로 예측되었으며 이는 장차 농업용수 개발 및 관리계획에 반드시 고려되어야 할 것이다. 본 연구는 한 개의 전지구 기후모형과 한 개의 지역기후모형의 결과만 이용한 점, SRES A2 시나리오에 대하여만 분석한 점, 및 불확실성에 대한 분석을 수행하지 않은 점 등의 제약점이 있으며, 앞으로 다양한 시나리오에 대하여 다른 모형을 이용한 결과에 대한 분석도 이루어 져야 할 것이다.

France 하천 수질 평가법으로 이용하는 규조류 지수에 관한 소개

정상옥 ( Sang Ok Chung ) 한국하천호수학회 2004 생태와 환경 Vol.37 No.4

Since, in 1970, diatoms and diatom indices was first used in measuring quality of streams and rivers at the Seine Water Agency in France, five other water agencies began to show interests since 1990. In 1994, associated with CEMAGREF (Centre National du Machinisme Agricole du Genie Rural et des Eaux et des Forets : environmental science and expertise for the sustainable management of land and water), the six French Water Agencies (Seine, Rhone-Mediterranee-Corse, Artois-Picardie, Loire-Bretagne, Rhin-Meuse and Adour-Garonne) developed a practical diatom index, which is liable to be used routinely in the territorial streams and rivers of whole France, and which is liable to promote and facilitate its use in monitoring water networks. In 1995, the first version of a biological diatom index (IBD) was generated by them. Since then, the software update for IBD calculation and the user`s network have led to numerous practical applications in France. Furthermore, the Water Agencies have run applicable programs on the National Basin Network from 1996, and the initial data set of IBD was completed. Re-examination of the complete data set was done at the end of 1998, and the tests on different calculation options of the IBD led to a third version of this index in June, 2000 (AFNOR NF T 90-354).

물수지분석 기법에 의한 논에서의 회귀율 조사분석

정상옥 ( Chung Sang Ok ),손성호 ( Son Seung Ho ) 한국농공학회 2001 韓國農工學會誌 : 전원과 자원 Vol.43 No.2

A water balance analysis was performed for a paddy field neighboring the Dongchang stream, downstream of the Unmun reservoir, which is constructed for the urban water supply. Daily rainfall data were collected and irrigation water flow rate, drainage flow rate, evaportranspiration, infiltration, and piezometeric head were measured in the field. The flow rates were continuously observed by water level logger during the growing season. The evaportranspiration and the infiltration were measured by N-type depletion meter and cylindrical infiltrometer, respectively. PVC pipes with 12mm diameter were used for piezometric head measurement. Total Irrigation and drainage flows were 3,608mm and 1,170mm in 1999, and 3,971mm and 1,548mm in 2000, respectively. The mean and range of the daily infiltration rate were 4.4mm/d and 3.4mm/d to 5.5mm/d in 1999 and 5.1mm/d and 4.1mm/d to 6.5mm/d in 2000, respectively. The net ground water flow including the change of soil water storage was 2,855mm in 1999 and 2,540mm in 2000. The evapotranspiration was 458.3mm in 1999 and 553.5mm in 2000. The range of daily evapotranspiration rate was from 1.6 to 8.7mm/d. The return flow ratio was about 32% in 1999 and 39% in 2000 and three year average was 35% including previous study in 1997. The amount of irrigation water was much higher than design standards or references in this study, This was caused by the inadequate water management practice in the area where water was oversupplied on farmers’ request rather than following sound water management principles.

농업용(農業用) 저수지(貯水池) 수문조작(水門操作) 모형(模型) 개발(開發)

정상옥 ( Chung Sang Ok ) 한국농공학회 1992 韓國農工學會誌 : 전원과 자원 Vol.34 No.2

A model using a linear programming technique was developed to operate gates for the optimum management of small or medium size agricultural reservoirs. To predict the inflow into the reservoirs the WASHMO model, which was a single event hydrology model, was modified and used. To test the applicability, the developed model was applied to two reser-voirs located in Kyungpook province. The results showed that the model could be used for the optimum gate operation of the agricultural reservoirs.