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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of The Korean Society of Agricultural Engineers
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Journal DOI :
The Korean Society of Agricultural Engineers
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Volume & Issues
Volume 54, Issue 6 - Nov 2012
Volume 54, Issue 5 - Sep 2012
Volume 54, Issue 4 - Jul 2012
Volume 54, Issue 3 - May 2012
Volume 54, Issue 2 - Mar 2012
Volume 54, Issue 1 - Jan 2012
Selecting the target year
HSPF Modeling for Identifying Runoff Reduction Effect of Nonpoint Source Pollution by Rice Straw Mulching on Upland Crops
Jung, Chung-Gil ; Park, Jong-Yoon ; Lee, Hyung-Jin ; Choi, Joong-Dae ; Kim, Seong-Joon ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 1~8
DOI : 10.5389/KSAE.2012.54.4.001
This study is to assess the reduction of non-point source pollution loads for rice straw surface covering of upland crop cultivation at a watershed scale. For Byulmi-cheon watershed (
) located in the upstream of Gyeongancheon, the HSPF (Hydrological Simulation Program-Fortran), a physically based distributed hydrological model was applied. Before evaluation, the model was calibrated and validated using 9 rainfall events. The Nash-Sutcliffe model efficiency (NSE) for streamflow was 0.62~0.78 and the NSE for water quality (Sediment, T-N, and T-P) were 0.68, 0.60, and 0.58 respectively. From the field experiment of 16 rainfall events, the rice straw covering reduced surface runoff average 10 % compared to normal surface condition. By handling infiltration parameter (INFILT) in the model, the value of 16.0 mm/hr was found to reduce about 10 % reduction of surface runoff. For this condition, the reduction effect of Sediment, T-N, and T-P loads were 87.2, 28.5, and 85.1 % respectively. The rice straw surface covering was effective for removing surface runoff dependent loads such as Sediment and T-P.
Characteristics and EMCs of NPS Pollutants Runoff from a Forest-Paddy Composite Watershed
Song, In-Hong ; Kang, Moon-Seong ; Hwang, Soon-Ho ; Song, Jung-Hun ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 9~17
DOI : 10.5389/KSAE.2012.54.4.009
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.
A Plot Scale Experiment to Analysis the NPS Reduction by Silt Fence and Vegetated Ridge for Non-Irrigated Cropland
Kim, Sung-Jae ; Park, Tae-Yang ; Kim, Sung-Min ; Jang, Jeong-Ryeol ; Kim, Sang-Min ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 19~27
DOI : 10.5389/KSAE.2012.54.4.019
The objective of this study was to test the pollutant reduction effect by the silt fence and vegetated ridge through field monitoring. The experiment plots were established with two replication and three treatments. Each plot was designed with 5 m width, 22 m length, and 3 % slope. Flumes with the floating type stage gages were installed at the outlet of each plot to monitor the runoff. For a rainfall monitoring, tipping bucket rain gage was installed within the experiment site. Cultivated crops were spring daikon and autumn chinese cabbage. Analysis of variance (ANOVA) indicated that the water quality concentration from three experiment plots were not significantly different in 5 % of significant level. The monitoring results showed that the average pollution loads reduced by silt fence compared to control were SS 75.33 %, TN 40.87 %, TP 56.58 %, BOD 52.12 %, COD 36.07 %, TOC 34.99 %; by vegetated ridge compard to control were SS 65.27 %, TN 81.80 %, TP 54.26 %, BOD 67.09 %, COD 46.55 %, TOC 43.30 %. Analysis of Spearman`s rank correlation coefficient showed that BOD-SS and SS-Turbidity were highly related at the silt fence and vegetated ridge plots. In all plots, SS-Turbidity and TP-TN relations were relatively high. The monitoring results showed that the silt fence and vegetated ridge were effect method to reduce the pollutant loads from the field runoff. Long-term monitoring is required to obtain more quantitative reduction effect for diverse crops and to increase the reliability of results.
Discharge Uniformity and Performance Assessment of Drip Irrigation System
Nam, Won-Ho ; Choi, Jin-Yong ; Choi, Soon-Kun ; Hong, Eun-Mi ; Jeon, Sang-Ho ; Hur, Seung-Oh ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 29~38
DOI : 10.5389/KSAE.2012.54.4.029
Drip irrigation is a affordable irrigation under structured cultivation. Drip irrigation system with high uniformity can be achieved through effective design, maintenance and management of irrigation systems. Nevertheless the design guidelines have not been established for the drip irrigation system products in domestic and imported considering cultivation method and greenhouse environment in Korea. The objectives of this study were to evaluate the performance of drip irrigation system with uniformity through an experiment. The experiment was conducted to study with nine different types of emitters produced in domestic and imported. Hazen-Williams coefficients were also estimated for the drip emitter through hydraulic simulation for design use. It was found that approximately 91.5 % for 10 cm emitter spacing and 96.2 % for 30 cm emitter spacing of statistical uniformity were observed in respectively. Average emission uniformity was decreased as the reduction of emitter spacing. The results would be used in the drip irrigation system design and guideline construction.
Probability Analysis of Plane Strain Element using Boundary Element Method
Jeon, Jeong-Bae ; Yoon, Seong-Soo ; Park, Jin-Seon ; Lee, Hyeong-Ryeol ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 39~46
DOI : 10.5389/KSAE.2012.54.4.039
The objectives of this study is intended to analyze stresses using the boundary element method and probability analysis for agricultural structure. Loads and material properties are an important factor when analyzing the structure. Until now, designing structure, loads and material properties are applied deterministic value. However, load and material properties involve uncertainties due to those change probabilistic and deterministic methods could not consider uncertainties. To solve these problems, the reliability analysis based on probability properties scheme was developed. Reliability analysis is easy to approach to analysis frame structure, however it has limitation when solving plane stress strain problems a kind of agricultural structures. The BEM (Boundary Element Method) is able to analysis plane strain problems by boundary conditions. Thus, this study applied boundary element method to analysis plane strain problem, load and material properties as a probabilistic value to calculate the analytical model using Monte Carlo simulations were developed.
Evaluation of the Performance of One-way Drainage Filter by Field Test
Seo, Dong-Uk ; Kim, Hyeon-Tae ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 47~53
DOI : 10.5389/KSAE.2012.54.4.047
It is needed to install a one-way drainage filter to prevent a seepage from lake or river outside of embankment and to promote a drainage from a flood inside of embankment when dikes such as lake dike, river dike, etc are constructed. However, the results of research for one-way drainage filter are insufficient. Therefore, through the field test of one-way drainage filter, this study checked a function of one-way drainage filter with a test of performance. As a result of field test, water flow in dike was blocked in the interception direction of the section that one-way drainage filter was installed, but water passed to the flow allowance direction of the section. Therefore we confirmed the function of one-way drainage filter. Seepage quantity in the flow allowance direction of the one-way drainage filter section was low as 74.6~80.5 % than that in the section without installation of filter because of a reduction effect of seepage with filter. And seepage quantity of field test was low as 64.3~90.0 % than that in results of seepage analysis because the coefficient of permeability of embankment in field is different from the results of laboratory test. In the future, more study will be needed to solve several problems which are related to fix the filter on slide, durability of filter, etc.
Monitoring of Hydrological and Water Quality in Dongjin-River Hengjeong Bridge Watershed for Agricultural Watershed Non-Point Pollutant Sources Management
Son, Jae-Gwon ; Son, Tae-Ho ; Choi, Jin-Kyu ; Jo, Jae-Young ; Goh, Nam-Young ; Oh, Jin-Hyu ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 55~63
DOI : 10.5389/KSAE.2012.54.4.055
This study was performed to investigate the stream water quality characteristics in Hengjeong Bridge Basin of Dongjin River during twelve months from October, 2010 to September, 2011. Also, pollutant loads were calculated on the basis of the water quality and runoff results. The results showed that ranges of water temperature, pH and EC were
respectively. The Concentration of DO, BOD, COD, SS, Tot-N and Tot-P were observed as 6.80~9.20 mg/L, 0.40~1.60 mg/L, 1.96~4.41 mg/L, 59.60~142.20 mg/L, 1.28~3.52 mg/L, 0.001~0.07 mg/L respectively. Tot-N showed correlativity with BOD, and Tot-P showed correlativity with SS. The runoff pollutant loading of Tot-N and Tot-P were 117.94 kg/ha and 2.06 kg/ha respectively, in Hengjeong bridge of Dongjin river watershed. In the case of the correlativity between runoff pollutant loads and concentrations, Tot-N and Tot-P show low significant relationships.
Estimation of Surface Runoff from Paddy Plots using an Artificial Neural Network
Ahn, Ji-Hyun ; Kang, Moon-Seong ; Song, In-Hong ; Lee, Kyong-Do ; Song, Jeong-Heon ; Jang, Jeong-Ryeol ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 65~71
DOI : 10.5389/KSAE.2012.54.4.065
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.
Prediction of Crest Settlement of Center Cored Rockfill Dam using an Artificial Neural Network Model
Kim, Yong-Seong ; Kim, Bum-Joo ; Oh, Sang-Eun ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 73~81
DOI : 10.5389/KSAE.2012.54.4.073
In this study, the settlement data of 32 center cored rockfill dams (total 39 monitored data) were collected and analyzed to develop the method to predict the crest settlement of a CCRD after impounding by using the internal settlement data occurred during construction. An artificial neural network (ANN) modeling was used in developing the method, which was considered to be a more reliable approach since in the ANN model dam height, core width, and core type were all considered as input variables in deriving the crest settlement, whereas in conventional methods, such as Clements`s method, only dam height is used as a variable. The ANN analysis results showed a good agreement with the measured data, compared to those by the conventional methods using regression analysis. In addition, a simple procedure to use the ANN model for engineers in practice was provided by proposing the equations used for given input values.
General Circulation Model Derived Climate Change Impact and Uncertainty Analysis of Maize Yield in Zimbabwe
Nkomozepi, Temba D. ; Chung, Sang-Ok ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 83~92
DOI : 10.5389/KSAE.2012.54.4.083
A Study on Change of Soil-Water Retention Curve with Different Net Confining Pressures and Porosities using a Suction-Saturation Control Technique
Lee, Joon-Yong ; Yu, Chan ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 93~103
DOI : 10.5389/KSAE.2012.54.4.093
A suction-saturation control technique based on flow pump system was developed to investigate hydraulic properties in unsaturated soils. The flow pump system is designed based on the principle of the axis-translation technique and triaxial equipment, and gives the suction-time and suction-saturation curves, the primary relationship needed for interpreting the response of unsaturated soils and link between theory and the material properties in unsaturated soil mechanics. Using the suction-saturation control technique, suction-time relationship and soil-water retention curve (SWRC) during hydraulic hysteresis were investigated with different net confining pressures and porosities. Three types of soils-two sands and a silt were used in this paper. This paper showed the effect of the hysteresis on the SWRC due to different net confining pressures and porosities. This means that a careful decision must be made as to which condition is to be modeled, since the delicate difference of the conditions in physical modeling can cause the different experimental output.
Analysis of Soil Moisture Characteristics in Nut Pine Forest about Seasons and Soil Layers
Hong, Eun-Mi ; Choi, Jin-Yong ; Yoo, Seung-Hwan ; Nam, Won-Ho ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 105~114
DOI : 10.5389/KSAE.2012.54.4.105
Soil moisture plays a pivotal role in hydrological processes, especially in the forest which covers more than 64% of the national land. Soil moisture was monitored to analyze soil moisture change characteristics in terms of time and soil layers in this study. 2 Years soil moisture change data was obtained from the experimental nut pine forest and statistical analysis including auto-correlation and cross-corelation among soil moisture data from different soil layers was conducted. Using the monitored soil moisture data, a relationship between soil moisture change and precipitation was analyzed and seasonal soil moisture change characteristics were analyzed. From the result of inter-relationships among soil layers in terms of season and time lag, soil moisture change characteristics in the nut pine forest were upper soil layers were much sensitive than lowers, and seasonal variation if soil moisture for upper soil layers were bigger than lowers showing low correlation with precipitation in winter and spring due to freezing and snowfalls.
Evaluation the Climatic Influence during El Nino and La Nina Periods of Aridity Index, Precipitation Effectiveness and Runoff in Basins
Lee, Jun-Won ; Kim, Gwang-Seob ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 115~125
DOI : 10.5389/KSAE.2012.54.4.115
The comparison between the spatial and temporal variability of aridity index, precipitation effectiveness and runoff during El-Nino and La-Nina periods and that of the normal period was conducted to evaluate the regional impacts of El-Nino, La-Nina in hydrologic variables. Aridity index and precipitation effectiveness were estimated using 59 nationwide weather stations data and runoff data of WAMIS were used. The ratio of the difference between El-Nino, La-Nina year value and that of normal year was analyzed. Temporal variation demonstrated that aridity index, precipitation effectiveness and run-off discharge increase in March, April, August, November, December and decrease in February, June, September, October according to El-Nino effect. Aridity index, precipitation effectiveness and run-off discharge increase in March, May, September and decrease in June, August, November, December according to La-Nina effect. The spatial variation of those variables analyzed for different basins showed that impacts in the Han river basin relatively higher than that of other basins.
Assessing the Benefits of Incorporating Rainfall Forecasts into Monthly Flow Forecast System of Tampa Bay Water, Florida
Hwang, Sye-Woon ; Martinez, Chris ; Asefa, Tirusew ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 127~135
DOI : 10.5389/KSAE.2012.54.4.127
This paper introduced the flow forecast modeling system that a water management agency in west central Florida, Tampa Bay Water has been operated to forecast monthly rainfall and streamflow in the Tampa Bay region, Florida. We evaluated current 1-year monthly rainfall forecasts and flow forecasts and actual observations to investigate the benefits of incorporating rainfall forecasts into monthly flow forecast. Results for rainfall forecasts showed that the observed annual cycle of monthly rainfall was accurately reproduced by the
percentile of forecasts. While observed monthly rainfall was within the
percentile of forecasts for most months, several outliers were found during the dry months especially in the dry year of 2007. The flow forecast results for the three streamflow stations (HRD, MB, and BS) indicated that while the 90 % confidence interval mostly covers the observed monthly streamflow, the
percentile forecast generally overestimated observed streamflow. Especially for HRD station, observed streamflow was reproduced within
percentile of forecasts while monthly rainfall observations closely followed the
percentile of rainfall forecasts. This was due to the historical variability at the station was significantly high and it resulted in a wide range of forecasts. Additionally, it was found that the forecasts for each station tend to converge after several months as the influence of the initial condition diminished. The forecast period to converge to simulation bounds was estimated by comparing the forecast results for 2006 and 2007. We found that initial conditions have influence on forecasts during the first 4-6 months, indicating that FMS forecasts should be updated at least every 4-6 months. That is, knowledge of initial condition (i.e., monthly flow observation in the last-recent month) provided no foreknowledge of the flows after 4-6 months of simulation. Based on the experimental flow forecasts using the observed rainfall data, we found that the 90 % confidence interval band for flow predictions was significantly reduced for all stations. This result evidently shows that accurate short-term rainfall forecasts could reduce the range of streamflow forecasts and improve forecast skill compared to employing the stochastic rainfall forecasts. We expect that the framework employed in this study using available observations could be used to investigate the applicability of existing hydrological and water management modeling system for use of stateof-the-art climate forecasts.
Estimation of the Relative Density and Internal Friction Angle for Sand using Cone-tip Resistance of the PCPT
Park, Jae-Sung ; Son, Young-Hwan ; Noh, Soo-Kack ; Bong, Tae-Ho ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 4, 2012, Pages 137~145
DOI : 10.5389/KSAE.2012.54.4.137
Sand is one of the essential materials used for social infrastructure construction such as embankment, landfill and backfill. It was known that mechanical properties and shear strength of sand are closely related to relative density. Therefore it is very important to determine accurate relative density. In this study, Portable Cone Penetration Tester (PCPT) was used to estimate the relative density and the internal friction angle of sand. PCPT cone-tip resistance (
) was measured changing the relative density of the two soil samples.Standard sand (JMJ) and Busan sand (BS). Also, a direct shear test was performed to investigate relationship between relative density and internal friction angle. The size and shape of soil particles were confirmed by using Scanning Electron Microscope (SEM). As a result, the log value of
was linearly correlated with relative density and internal friction angle. In particular, the internal friction angle of BS sample was greater than that of JMJ, which was due to difference of the shape and mean size of particles. This result shows that it is important to determine the shape and size of particles as well as relative density to define mechanical property of sand. Through this study, it can be more effectively and conveniently to investigate relative density and shear strength of sand by using PCPT in situ.