• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.6
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• pp.43-53
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• 2022

Rice paddy has been actively converted into upland crop fields as more profitable upland crop cultivation are encouraged along with the decrease in rice consumption. However, the current water supply system remains mainly for paddy water supply, so research on pipeline water supply for upland cultivation is needed. The objective of this study was to optimize storage tank installation locations for pipeline water supply in reservoir irrigation districts. Five of reservoir irrigation districts were selected as the study sites and gridded of 10×10 m in size. Then genetic algorithm was adopted to evaluate the effects of spatial storage tank allocation on total pipeline cost. The lengths of the main and branch pipelines were considered as the objective cost function for the optimization of storage tank installation. Overall the shorter the branch pipeline and the longer the main pipeline, as the number of storage tanks increase. The minimal pipeline cost, i.e., optimal condition was reached when approximately 10% of the storage tank numbers to total upland plots were installed. The methodology presented in this study can be applied to determine the number and spatial arrangement of storage tanks for upland pipeline irrigation system design.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.785-798
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• 2023

Considering irrigation facilities are currently insufficient and drought vulnerability due to climate change is high, efficient measures are required to secure water supply for field crops. This study, therefore, calculated the water shortage to secure water for representative field crops. An economic analysis was further conducted by comparing the production income to the input cost for each method. Here, five distinct regions were selected to represent each crop-Cheongyang-gun for chili peppers, Yesan-gun for apples, Dangjin-si for cabbages, Seosan-si for garlic, and Goesan for beans. The regions with insufficient water supply were estimated by calculating the water requirements and the supplied water from public groundwater wells for each area. A comprehensive set of four scenarios was presented as a strategy to ensure water security and manage irrigation facilities. These scenarios comprised the maintenance of existing groundwater wells, the construction of new water storage tanks, the installation of additional groundwater wells, and the utilization of surface water. B/C (benefit/cost) analysis was conducted for each scenario. As a result, the construction of water storage tanks was selected as a facility and water management plan in Cheongyang-gun, Dangjin-si, and Seosan-si. The analysis additionally indicated the economic viability of installing surface water utilization facilities in Yesan-gun and developing water storage tanks and groundwater (aquifer) wells in Goesan-gun. The results of this study are considered to serve as foundation data that may be utilized in the selection of water management plans for drought-prone areas in the future.

• International Journal of Advanced Culture Technology
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• v.6 no.3
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• pp.178-186
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• 2018

Generally, in terms of the development of irrigation scheme, the efficient water resource management that supplies the irrigation water in consideration of the required time and accurate quantity to grow the crop should be conducted. The water resource assessment should precede to supply the irrigation water efficiently. The water resources assessment is divided into the water requirement analysis and the water availability assessment. In case of Korea, the major crop is paddy rice unlike crops of Africa, such as sugarcane, maize, and cassava, etc. Because it is not familiar with the method for upland irrigation development in tropical area, it needs to know the water resources assessment for irrigation scheme development about these crops. The Natama Scheme in Chiradzulu District of the Southern Malawi was selected as study area, which has tropical climate. From the collected meteorological data, the evapotranspiration was analyzed by Penman-Monteith Method and the effective rainfall was analyzed by USDA Soil Conservation Service Method. This study displays the results that for study area, the evapotranspiration varies from 2.80 mm/day to 5.51 mm/day and the effective rainfall varied from 2.1mm to 149.0mm. According to the selected crop (Green Maize, Dry Maize), the unit water requirement (UWR) and water demand (WD) considering the irrigation efficiency, irrigation time and irrigation area were estimated to be $0.00122m^3/s/ha$ and $0.0122m^3/s$ respectively. For the water availability assessment, the runoff of Natama scheme was calculated by specific yield method. The water availability was evaluated through reviewed differences of discharge between $Q80_{intake}$ and Total WD, and the irrigation water can be supplied sufficiently in the existing 10ha of Natama scheme. As a result of reviewing the extensibility of irrigable area, total WD of scheme is $0.02313m^3/s$, and $Q80_{intake}$ is $0.02387m^3/s$ ($Q80_{intake}$ > Total WD). Therefore, Natama scheme can be extended from 10 ha to 17 ha in the dry season in consideration of the $Q80_{intake}$.

• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.2
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• pp.13-24
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• 2024

This study aims to contribute to efficient paddy field water management by developing an IoT-based automatic paddy inlet that can consider water level changes according to variations in the supplied water quantity through irrigation channels. This IoT-based automatic paddy inlet not only ensures water level changes based on the supply of irrigation water but also secures irrigation efficiency. The effectiveness and efficiency of the developed IoT-based automatic paddy inlet were presented to contribute to efficient paddy field water management. As a result, the IoT-based automatic paddy inlet demonstrated the capability to maintain the optimal water level in the paddy field. Particularly, it exhibited up to 18.4% higher water resource usage efficiency compared to conventional paddy inlet, emphasizing the IoT-based automatic paddy inlet's advantage in terms of water resource usage.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.6
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• pp.111-118
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• 2020

This study developed a rainwater harvesting system for the irrigation of upland on sloping area. The assessment of water supply capacity was evaluated in farm field experience. This system consists of a water catchment device and a collapsible storage tank. The water catchment device was designed to collect runoff water in natural channel of 500 mm width into a pipe of 50 mm inner diameter. The device has funnel-shaped plan and cross-section of square. The storage capacity of the collapsible water tank was caculated to meet the water demand for irrigation in 30 a cultivated land for 10-year frequancy drought. The tank has a cuboid shape with a capacity of 30 ㎥, 5 m in width and length, 1.2 m in height. This system can supply 92% of the water required for drop irrigation of red pepper and 88% of the water required for drop irrigation of onions in 30 a cultivation land during the month of May and June. In the case of 16-dry days of 10-years frequency, this system is capable to irrigate 100% of required water for red pepper and onion, 76.7% of required water for Omija (Schisandra chinensis), and 51.5% of required water for autumn kimchi cabbage.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.2
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• pp.85-96
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• 2021

Irrigation return flow is defined as the excess of irrigation water that is not evapotranspirated by direct surface drainage, and which returns to an aquifer. It is important to quantitatively estimate the irrigation return flow of the water cycle in an agricultural watershed. However, the previous studies on irrigation return flow rates are limitations in quantifying the return flow rate by region. Therefore, simulating irrigation return flow by accounting for various water loss rates derived from agricultural practices is necessary while the hydrologic and hydraulic modeling of cultivated canal-irrigated watersheds. In this study, the irrigation return flow rate of agricultural water, especially for the entire agricultural watershed, was estimated using the SWMM (Storm Water Management Model) module from 2010 to 2019 for the Madun reservoir located in Anseong, Gyeonggi-do. The results of SWMM simulation and water balance analysis estimated irrigation return flow rate. The estimated average annual irrigation return flow ratio during the period from 2010 to 2019 was approximately 55.3% of the annual irrigation amounts of which 35.9% was rapid return flow and 19.4% was delayed return flow. Based on these results, the hydrologic and hydraulic modeling approach can provide a valuable approach for estimating the irrigation return flow under different hydrological and water management conditions.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.153-162
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• 2023

It is important to determine water movement at the growing substrate used in soil-less cultivation for better management of water supply. Numerical simulation is a fast and versatile approach to evaluate highly accurate water distribution. The objective of this study is to simulate the water movement in rockwool as a soil-less medium using HYDRUS-2D. HYDRUS-2D was used to simulate the spatial and temporal water movement in two types of rockwool slabs (Floriculture (FL), high density; Expert (EP), low density). The simulation was performed at two pulse conditions: 10 min ON and 50 min OFF (case A), 20 min ON and 40 min OFF (case B). The total irrigation amounts were the same at both cases. In case A, during the irrigation ON, the water contents at FL increased 1.93-fold faster than the values at EP. Whereas, during the irrigation OFF, the decreasing rate of water contents at FL was almost the same as one at EP. At case B, these values were not changed much from case A. However, the duration of optimum water content (50% - 80%) was 15.0 min and 23.5 min at case A and case B, respectively. Thus, FL and 20 min ON and 40 min OFF (case B) could supply water to rockwool much faster and longer than EP. Once qualitatively validated, this simulation of water movement in rockwool could be used to design an effective optimum irrigation method for vegetables.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.3
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• pp.13-17
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• 2011

There was a transition from participatory irrigation management (PIM) to public irrigation management (PubIM) in Korea when Korea Rural corporation and Community (KRC) merged with Farm Land Improvement Associations (FLIAs), which had managed 60 % of irrigation areas. While making a number of achievements, some problems occurred in the public irrigation management, such as lack of farmers' participation, increased amount of water usage, and elevating operating costs. Accordingly, this paper suggested ways to increase efficiency in water usage and reduce operating costs under the public management through the motive power of farmers participation. First, WUGs replaced the discarded water management committee should be reorganized to revive the concept of PIM in the form of autonomously reinforced one and the roles and functions of WUGs and the board of representatives should be strengthened. The member of new type of WUGs should participate in the national and regional water management committees as a stakeholder of irrigation water user. And also new type of WUGs initiates not only the management of irrigation water but also the management of irrigation water quality and non-point source pollution in the watersheds. Those additional activities of WUGs should be properly compensated. Second, subsidies (direct payments) should be provided to faithful farmers as an incentive for their labor supply. Third, water fees could be charged to large scale agriculture companies. Fourth, professional managers could be hired, management targets would be adjusted, and incentives should be offered. These efforts are expected to improve the irrigation management by encouraging farmers' participation under public system.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.1-7
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• 1998

To investigate the water balance in a paddy rice field with the pumping station for irrigation water supply, flow measurements and analysis on various components of water balance were carried out. The investigated area is 103.7 ha, and the irrigation water was supplied for 102 days during the total irrigation period starting from June 1. It was found that the consumption rate was increased as the growing stage was progressed. The variation of evapotranspiration rate was shown same tendency as the consumption rate, while no apparent tendency was found in infiltration rate upon different growing stages. And the ground water input to the area was predominant during the early stage of growing period, while ground water output from the study area was predominant at the end of the growing stage. The range of return flow rate, the ratio of total outflow to total inflow in every decad, was 57.6 to 85.7%. These values are slightly higher than reported values from the other investigation projects.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.7
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• pp.71-80
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• 2004

A system for estimating daily paddy irrigation water requirements was developed to simulate daily stream flows that reflect various upstream and downstream return flows from river basin. Evapotranspiration in paddy fields was estimated using the modified Penman equation. Daily irrigation water requirements of paddy fields were calculated by multiplying the paddy area and the daily decrease in ponding depth. The system was constructed almost completely using images, grids, etc. in Visual Basic 6.0. The developed model was verified in the Damyang dam, and was used to estimate daily paddy irrigation water requirements at 12 small watersheds in Geum river basin for 20 years, from 1983 to 2002, covering paddy field areas of $3,332\~26,422$ ha. The results on the runoff analysis on the inflow to the Daecheong multi-purpose dam with various return flows were satisfactory. They were reasonable compared to the scenario where return flows were not considered.