• Magazine of the Korean Society of Agricultural Engineers
• /
• v.34 no.E
• /
• pp.12-19
• /
• 1992

The effects of drainage system on evapotranspiration and drainage flows are studied. Data from drainage field experiment at Castalia in North Central Branch, Ohio Agricultural Research and Development Center were used in this study. A water table management model, ADATP (Agricultural Drainage and Pesticide Transport), which was developed by combining the GLEAMS and the subsurface drainage part of the DRAINMOD model with several modifications, was evaluated and used to predict hydrologic components. The ET is very much affected by the presence of tile drainage system but not significantly affected by the surface drainage system. The combined surface and subsurface drainage system gives the largest total outflow values while the surface drainage only system gives the smallest. Comparisons of model predicted and measured values of surface runoff only, subsurface drainage only, and combined surface runoff and subsurface drainage system are in satisfactory agreement. The model predicted values are within the range of the variations of the observed replications in general. Based on the results of the model evaluation study, it is concluded that ADAPT model can be used to design water table management systems.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.55 no.3
• /
• pp.63-73
• /
• 2013

The objectives of this study were to develop a hydrologic simulation model to estimate surface drainage for irrigation districts consisting of paddy and protected cultivation, and to evaluate the applicability of the developed model. The model consists of three sub-models; agricultural supply, paddy block drainage, and protected cultivation runoff. The model simulates daily total drainage as the sum of paddy field drainage, irrigation canal drainage, and protected cultivation runoff at the outlets of the irrigation districts. The agricultural supply sub-model was formulated considering crop water requirement for growing seasons and agricultural water management loss. Agricultural supply was calculated for use as input data for the paddy block sub-model. The paddy block drainage sub-model simulates paddy field drainage based on water balance, and irrigation canal drainage as a fraction of agricultural supply. Protected cultivation runoff is calculated based on NRCS (Natural Resources Conservation Service) curve number method. The Idong reservoir irrigation district was selected for surface drainage monitoring and model verification. The parameters of model were calibrated using a trial and error technique, and validated with the measured data from the study site. The model can be a useful tool to estimate surface drainage for irrigated districts consisting of paddy and protected cultivation.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.46 no.3
• /
• pp.3-14
• /
• 2004

A two-dimensional numerical model based on a finite volume method was formulated to solve the shallow water equations and applied for evaluating drainage characteristics at large-sized paddy fields. Manning roughness coefficient was calibrated using the observed inundating depths at drainage tests, and used for validating the model with the results from another drainage test. The simulated results were in good agreement with the observed inundating depths. The result of surface drainage showed that the longer width of the outlet was or the more the number of drainage outlet was, the shorter the drainage time was taken, and the larger the size of the field become, the longer the drainage time was taken, and the field shape had little effect on drainage time. To reduce the drainage time to 24 hours, the outlet is located lower than the elevation of the basin and small drainage ditch is constructed at the field. The results showed that the drainage time was taken short as the small drainage ditch was constructed. The comparison of drainage time as to the size of field constructed small drainage ditch showed the field, 100m ${\times}$ 200 m, can be drained in 24 hours.

• Korean Journal of Ecology and Environment
• /
• v.38 no.spc
• /
• pp.58-61
• /
• 2005

Environmental polluting materials from road surface drainage are a significant nonpoint source influenced to the eutrophication of lake and ecosystems with a transport development in recent years. To elucidate the discharge characteristics, the changing patterns in concentrations of polluting materials such as suspended solid (SS), chemical oxygen demand (COD), nitrogenous and phosphorus nutrients in drainage waters, were investigated during rainfall. Load variation of COD concentration in drainage water samples was closely related to that of SS concentration. This indicates that SS contained a greater part of organic matter. A quite difference between the past pavement and the new well-drainage pavement system was observed in the concentrations of SS and COD in drainage waters. Appreciable concentrations of nitrite and nitrate were determined in drainage waters. The present results indicate that the drainage water from road surfaces is a significant nonpoint source, and that the well-drainage pavement system introduced to skid prevention has an effect on the decreases of pollutants.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2003.03a
• /
• pp.481-484
• /
• 2003

Sulfide minerals contacted with air and water in coal seam cause oxidation reactions. This oxidation reactions make low pH of groundwater and surface water(Acid Drainage). The reddish brown precipitate collected from the cut slope of the study area was estimated using the X-Ray Diffractometer(XRD). XRD results show that the cut slope was affected by Acid Drainage. The cut slope exposured to Acid Drainage become weak about chemical weathering and defile the appearance of the road. Drainage facilities are very important in Cut Slope under Acid Drainage influence. Reactions between Coal seam and water cause chemical weathering and environmental problem. Therefore It is important to control the transfer paths of groundwater and surface water and to install water collecting facilities

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.45 no.7
• /
• pp.57-69
• /
• 2003

To evaluate nutrient dynamics with different fertilization in paddy field and develop water quality model, mass balance analysis was performed during growing season of 2001-2002 in field experimental plots irrigated with groundwater. As a result of water balance analysis, most of outflow was surface drainage as about half of total outflow and about 500mm was lost by evapotranspiration. The water budget was well balanced. The runoff from paddy field was influenced by rainfall and forced drain. Especially runoff during early cultural periods more depends on the forced drain. As a result of mass balance analysis, most of nutrient was input by fertilization and lost by plant uptake. Significant amount of nitrogen were supplied by precipitation and input from upper paddy field, comprising 12%∼28% of total inflow. Nutrient loading by surface drainage was occurred showing about 15%∼29% for T-N and 6%∼13% for T-P. The response of rice yield with different fertilization was not significant in this study. Water quality model for paddy field developed using Dirac delta function and continuous source was calibrated and validated to surface water quality monitoring data. It demonstrates good agreement between observed and simulated. The nutrient concentration of surface water at paddy field was significantly influenced by fertilization. During early cultural periods when significant amount of fertilizer was applied, surface drainage from paddy field can cause serious water quality problem. Therefore, reducing surface drainage during fertilization period can reduce nutrient loading from paddy fields. Shallow irrigation, raising the weir height in diked rice fields, and minimizing forced surface drainage are suggested to reduce surface drainage outflow.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.10a
• /
• pp.861-868
• /
• 1999

Drainage concrete pavement, unlike water permeable concrete pavement, is to preclude the pavement from overflowing with water, such as rain water, from infiltrating into earth by placing a border in the middle layer which makes water to flow through the surface of the border to the conduit. Drainage concrete pavement enhances car wheel resistance to slippery and wet road surface and imbibes noise caused by friction on the road. Also, by using pigment, it adds to the beauty of the environment. Drainage concrete pavement can be used for sidewalks, roadways, parking lots and expressways.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.16 no.3
• /
• pp.219-224
• /
• 1996

Silage comkv, suwwn 19). sorghum $\times$ sudangrass(p. 988) and winter ryeNaton) were cultivated on imperfectly drained paddy field under two different draining methods, subsurface darinage by PVC pipes and open ditsched surface drainage. The crops were harvested at the stage of hard dough for corn and soft dough for wrghum and rye. The soil physical properties. soil colors. soil structure and soil wetness were improved in the subsurface drainage. Gravitational water table occured depth in 110 cm(dry season)~75cm(rain season). In soil profile description, yellowish brown with yellowish red mottles and well developed granular structure were found in the surface A horizon. The portion of solid phase in subsoils(B horizon) was reduced from 48.6%(undrained) to 43.7 %. A blocky structure with dark gray to gray were described in the open ditsched surface drainage. Severe wet depression of the crops was observed due to it's higher moisture contents, where the gravitational water occured depth in 25~37cm during the rainy season. The chemical properties of paddy soils were less affected by drainage methods. The concentration of available phosphate. organic matter and exchangeable K, Ca and Mg were decreased in the subsurface drained soils. The annual dry matter yields of com-rye cropping were 17.8 ton in the undrained, 21.6 ton in the open ditsch drainage and 35.9 ton/ha in the subsurface drainage.

• Journal of the Korean Geotechnical Society
• /
• v.32 no.5
• /
• pp.37-48
• /
• 2016

This study aims to figure out the behavior of runoff and drainage of pervious sidewalk block in actual construction environment by experiments. The specimens with surface layer and bedding layer are subjected to the drainage test by considering unsaturated condition and unique rainfall condition in urban areas. The repeated drainage test and clogging test were conducted with time intervals, and 3D X-ray CT image analysis and evaporation test were carried out for a quantitative analysis of drainage test. The results present that the spatial distribution of pores by evaporation for time intervals induces runoff. Especially, the bedding layer under the block is significantly critical in overall hydraulic behavior such as drainage and evaporation compared to the surface layer. Moreover, the sediments in pores promote the change in pores by evaporation and this induces deteriorated drainage capacity which is hard to recover. In addition, it is revealed that the maximum runoff height grows as the drainage capacity declines depending on the pre-wetting condition.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.8
• /
• pp.449-455
• /
• 2019

The increase in impermeable pavement from recent urbanization has resulted in an increase in surface runoff. The surface runoff has also increased the burden of the existing drainage system. This drainage system has structural limitations in that the catchment area is reduced by the waste particles transported with the surface runoff. In addition, the efficiency of the drainage system is decreased. To overcome these limitations, a new type of drainage system with a drainage layer was developed and applied. In this study, various volume porosity and permeability of the lower drainage layer were simulated using ANSYS CFX, which is a three dimensional computational fluid dynamics program. The results showed that the outlet velocity of the 35% volume porosity was faster than that of the 20% and 50% cases, and there was no relationship between the volume porosity and drainage performance. The permeability of the drainage layer can be determined from the particle size of the material, and a simulation of five conditions showed that 2 mm sand grains are most suitable for workability and usability. This study suggests appropriate values of the volume porosity and particle size of the drainage layer. This consideration can be advantageous for reducing and preventing flood damage.