Water Use Efficiency of Subsurface Drip Irrigation and Furrow Irrigation

송인홍,피터 월러,최연식,권순국,Song, In-Hong,Waller Peter. M.,Choi, C. Yeon-Sik,Kwun, Soon-Kuk The Korean Society of Agricultural Engineers 2007 한국농공학회논문집 Vol.49 No.2

The primary objective of this study was to compare water use efficiencies between subsurface drip irrigation and furrow irrigation. The uniformity of used drip lines was tested to determine if clogging would be a threat to the long-term success of a subsurface drip irrigation system. Three crops, cantaloupe, lettuce, and bell pepper, were grown in four plots for each irrigation system. Significantly less water was applied with subsurface drip irrigation than with furrow irrigation (29.5 % less for cantaloupe and 43.2 % less for bell poppet) in order to produce similar crop yields. Water use efficiencies with subsurface drip irrigation were significantly higher than those with furrow irrigation fur cantaloupe (P-value = 0.018) and bell pepper (P-value ${\leq}$ 0.001). Drip-irrigated lettuce, a shallow-rooted crop, had moderately higher water use efficiency during the first two seasons, while no difference was observed in the third season. After the experiment, the uniformity of the drip lines was 92.1 % on average and classified as good. The high values fur water use efficiency and uniformity indicate that subsurface drip irrigation can be a sustainable method for conserving irrigation water.

산림논복합 소유역에서의 비점부하 강우유출 특성 및 EMC 산정

송인홍,강문성,황순호,송정헌,Song, In-Hong,Kang, Moon-Seong,Hwang, Soon-Ho,Song, Jung-Hun 한국농공학회 2012 한국농공학회논문집 Vol.54 No.4

This study was aimed to characterize non-point source (NPS) pollutant runoff and estimate event mean concentrations (EMCs) from a small rural watershed located at the headwater area of the Gyeongan stream. The study watershed consists of the two major landuse, forest (72 %) and paddy field (28 %). The nine rainfall events ranging from 18.5 to 192.6 mm in amount were monitored in this study. Stream flow was measured at the watershed outlet using a water level gauge, while a number of water samples for each event were collected and analysed for water quality. Event pollutant loads varied greatly depending on rainfall events varying from 22.6 to 3,134.2 mg/L, 0.32 to 24.56 mg/L, 0.090 to 1.320 mg/L, and 2.3 to 149.8 mg/L for SS, TN, TP, and COD, correspondently. The respective mean EMCs were estimated by 104.2, 1.00, 0.168, and 7.9 mg/L. The Pearson correlation analysis showed that COD EMC was significantly correlated with those of SS, TN, and TP. Rainfall runoff ratio appeared to be negatively correlated with EMCs of SS, TP, and COD, although not statistically significant. The event loads from the largest rainfall was greater than the sum of those from the remaining eight events. The study results suggest that the appropriate management of intensified storm events are of greater importance in curbing NPS loads, while the estimated EMCs provide base data for the unit pollutant loads determination for the forest-paddy composite upstream watershed.

미처리하수지구 논에서의 수질 및 토양 특성 분석

송정헌,정한석,박지훈,송인홍,강문성,박승우,Song, Jung Hun,Jeong, Han Seok,Park, Ji Hoon,Song, In Hong,Kang, Moon Seong,Park, Seung Woo 한국농공학회 2014 한국농공학회논문집 Vol.56 No.6

The objectives of this study were to monitor and analyse water quality and soil property in paddy fields where untreated wastewater is irrigated. Three paddy fields where streamflow mixed with untreated wastewater has been irrigated (untreated wastewater district, UWD) were selected for monitoring, and five paddy fields in Yongin area (Yongin district, YID) where water from Idong agricultural reservoir (well-managed) has been irrigated were selected for comparative evaluation. Electronic conductivity (EC), suspended solids (SS), total nitrogen (T-N), total phosphorous (T-P), $NO_3-N$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$, total coliform (TC), fecal coliform (FC), and E. coli of the irrigation water in the UWD were significantly higher than those in the YID. Relatively high concentrations of EC, T-N, T-P, TC, FC, E. coli, copper (Cu), lead (Pb), zinc (Zn), and aluminium (Al) were shown in the irrigation water of the UWD especially during May to June. In general, the paddy soil in the UWD contained more Pb, Zn, and Cu than in the YID although the soil heavy metal contents in the UWD still meet the Korean soil contamination warning standards. No temporal trends in the heavy metal concentrations were found in paddy soils of the UWD. This study showed that the use of untreated wastewater to paddy fields has the possibility of negative impacts on water quality and soil, although long-term monitoring is needed to fully evaluate its effects.

농촌 소하천의 재폭기 계수 추정

송인홍 ( Song In Hong ),권순국 ( Kwun Soon Kuk ) 한국농공학회 2000 한국농공학회 학술대회초록집 Vol.2000 No.-

In this study, using modified tracer method(Constant Rate Injection, CRI method), reaeration rates were measured in the territories of Bokha stream. In case of Kwanri stream, reaeration rates of a diversion were measured simultaneously. Propane gas and Rhodamine-WT were used as gas and dye tracer, respectively. The experimental results show that reaeration rates of the stream were ranged from 6.16 to 24.52 1/day and those of a diversion in Kwanri stream were ranged from 28.39 to 123.61 1/day. It is resulted that mean velocity of stream is a dominant factor in reaeration process and diversion significantly influence on reareation process.

농촌 소하천에서의 재폭기 계수 추정

송인홍 ( Song In Hong ),권순국 ( Kwun Soon Kuk ) 한국농공학회 2001 韓國農工學會誌 : 전원과 자원 Vol.43 No.5

Reaeration phenomena, the physical process of absorption of oxygen from atmosphere, is one of the important parameters of dissolved oxygen simulation in streams. This study was aimed at predicting reaeration coefficients in rural small streams, examining the influence of drop structure on reaeration and the seasonal fluctuation of reaeration coefficients. Reaeration coefficients of five strams including four tributaries of Bokha watershed in Gyeonggi Ichon and Onyang stream in Chungnam Onyang were measured. Constant rte injection (CRI) method using propane and Rhodamine-WT as gas and dye tracer was adopted. Reaeration Coefficients ranged between 6.16 and 29.16 reciprocal day, higher than those in USGS database. Prediction equation. K₂ = CV^0.593, was regressed from the measured data at 95% confidence level, with an absolute error of 21.2% and a standard error of 4.0 reciprocal days. Reaeration coefficients of experimental reaches with drop structure showed percentile increases of 42.3 to 159.2 compared to those without it, an indication that drop structure plays and important role on stream reaeration. Taking into consideration the seasonal fluctuation of reaeration coefficients, the values measured during September and October were the highest. Mainly due to the removal of aquatic plants, by intensive rainfall during summer.

농촌유역 모형의 모의요소별 적용기법

송인홍 ( Song In-hong ),강문성 ( Gang Mun-seong ),김진택 ( Kim Jin-taek ) 한국농공학회 2012 韓國農工學會誌 : 전원과 자원 Vol.54 No.1

농촌지역의 유량ㆍ부하량관계식 산정

송인홍 ( Song In Hong ),박병흔 ( Park Byung Heun ),권순국 ( Kwun Sun Kuk ) 한국농공학회 1999 한국농공학회 학술대회초록집 Vol.1999 No.-

This study was initiated to collect background pollutant data for rural watersheds. The effluent/run-off pollutant load and run-off ratio of the study areas were calculated and the two types of regression equations, L=aㆍQ+b and L=c ㆍQ^d where L and Q are the pollutant load(L) and discharge(Q), were derived. We acquired that the correlation coefficients of (he two types of regression equations were over than 90% except for BOD. Therefore, L-Q equations would be a measure to predict water quality of rural watersheds.

Sentinel-2 위성영상을 이용한 하계 논벼와 동계작물 재배 필지 분류 및 정확도 평가

홍주표 ( Hong Joo-pyo ),장성주 ( Jang Seong-ju ),박진석 ( Park Jin-seok ),신형진 ( Shin Hyung-jin ),송인홍 ( Song In-hong ) 한국농공학회 2022 한국농공학회논문집 Vol.64 No.1

Up-to-date statistics of crop cultivation status is essential for farm land management planning and the advancement in remote sensing technology allows for rapid update of farming information. The objective of this study was to develop a classification model of rice paddy or winter crop fields based on NDWI, NDVI, and HSV indices using Sentinel-2 satellite images. The 18 locations in central Korea were selected as target areas and photographed once for each during summer and winter with a eBee drone to identify ground truth crop cultivation. The NDWI was used to classify summer paddy fields, while the NDVI and HSV were used and compared in identification of winter crop cultivation areas. The summer paddy field classification with the criteria of -0.195<NDWI<0.15 was 90.9% accurate on average when compared with ground truth. Model performance for the winter crop field classification was also excellent showing the accuracy greater than 98.2% on average for both models. However, cloud and greenhouses appeared to demonstrate optical similarity with paddy in the NDWI values, implying additional caution should be taken when removing cloud and greenhouse effects. Overall the developed methods for paddy and winter crop classification performed reasonably well at the irrigation district level and further studies are needed to investigate model performance at regional or national scales.

비종에 따른 논에서의 배출부하량 영향평가

장승우,강문성,송인홍,장정렬,이은정,박승우,Chang, Seung-Woo,Kang, Moon-Seong,Song, In-Hong,Jang, Jeong-Ryeol,Lee, Eun-Jeong,Park, Seung-Woo 한국농공학회 2011 한국농공학회논문집 Vol.53 No.6

The main objective of this study was to evaluate the effects of control-release fertilizer (CRF) on pollutant loadings from a small watershed. The Baran watershed, 386 ha in size, was selected as the study site, and the AGNPS (Agricultural Non-point Source Pollution) model was used to evaluate the effects of fertilizer types. Digital maps of digital elevation (DEM), slope distribution, channel, flow direction, landuse, soil, and curve number were extracted from the study watershed. Model parameters related to hydrology and water quality were calibrated and validated by comparing model predictions with the observed data collected for 2 years (1999 to 2000). Calibration and validation resulted in $R^2$ values of 0.75-0.91 for all the water quality parameters. All the paddy fields (21.2 %) of the study watershed were sprayed by either CRF or NPK (standard fertilizer). In CRF application, total nitrogen (TN) load was 4.9% less than NPK application, however total phosphorus (TP) load was 0.7 % more than NPK application. In CRF application, considering only paddy fields in the study area, TN load was 38.7 % less than NPK application. Using CRF in paddy fields could be one of the ways to reduce pollutant loadings from agricultural watersheds, however, in order to confirm it, more researches about effects of using CRF are necessary.

인공신경망 기법을 이용한 논에서의 지표 유출량 산정

안지현,강문성,송인홍,이경도,송정헌,장정렬,Ahn, Ji-Hyun,Kang, Moon-Seong,Song, In-Hong,Lee, Kyong-Do,Song, Jeong-Heon,Jang, Jeong-Ryeol 한국농공학회 2012 한국농공학회논문집 Vol.54 No.4

The objective of this study was to estimate surface runoff from rice paddy plots using an artificial neural network (ANN). A field experiment with three treatment levels was conducted in the NICS saemangum experimental field located in Iksan, Korea. The ANN model with the optimal network architectures, named Paddy1901 with 19 input nodes, 1 hidden layer with 16 neurons nodes, and 1 output node, was adopted to predict surface runoff from the plots. The model consisted of 7 parameters of precipitation, irrigation rate, ponding depth, average temperature, relative humidity, wind speed, and solar radiation on the daily basis. Daily runoff, as the target simulation value, was computed using a water balance equation. The field data collected in 2011 were used for training and validation of the model. The model was trained based on the error back propagation algorithm with sigmoid activation function. Simulation results for the independent training and testing data series showed that the model can perform well in simulating surface runoff from the study plots. The developed model has a main advantage that there is no requirement for any prior assumptions regarding the processes involved. ANN model thus can be a good tool to predict surface runoff from rice paddy fields.