• Journal of The Korean Society of Agricultural Engineers
• /
• v.64 no.1
• /
• pp.27-37
• /
• 2022

This study established a water supply network based on the operation case of Mandae Reservoir in Yanggu-gun, Gangwon-do, to analyze the efficient distribution and management of agricultural water supplied from the reservoir to irrigation areas using the hydraulic analysis model SWMM. In order to construct a model to analyze the water canal network, network conditions needs to be simplified, and in particular, excessive detail or simplification of the irrigation area can lead to errors in the analysis results. Therefore, the effect of the water canal network model was analyzed by simulating the appropriate simplification process step by step. The results of simplifying the actual block shape of the analysis target area using SWMM showed that there was no significant difference in the results even if 7 lots were simplified to 2. Also, it was found that the construction and analysis of a simplified network model were reliable when the excess quantity was 2% or more compared to the required quantity for each case of analysis of the paddy field.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2004.11a
• /
• pp.95-95
• /
• 2004

• Korean Journal of Agricultural Science
• /
• v.48 no.1
• /
• pp.103-117
• /
• 2021

The severe effects of climate change, such as global warming and the El Niño phenomenon, have become more prevalent. In recent years, natural disasters such as drought, heavy rain, and typhoons have taken place, resulting in noticeable damage. Korea is affected by droughts that cause damage to rice fields and crops. Societal interest in droughts is growing, and measures are urgently needed to address their impacts. As the demand for high-quality agricultural products expands, farmers have become more interested in water management, and the demand for field irrigation is increasing. Therefore, we investigated water demand in the irrigation of drought-vulnerable crops. Specifically, we determined the water requirements for crops including cabbage, red pepper, apple, and bean in four regions by calculating the consumptive water use (evapotranspiration), effective rainfall, and irrigation capacity. The total consumptive water use (crop evapotranspiration) estimates for Dangjin-si (cabbage), Yesan-gun (apple), Cheongyang-gun (pepper) in Chungnam, and Goesan-gun (bean) in Chungbuk were 33.5, 206.4, 86.1, and 204.5 mm, respectively. The volumes of groundwater available in the four regions were determined to be the following: Dangjin-si, 4,968,000 m³; Yesan-gun, 4,300,000 m³; Cheongyang-gun, 1,114,000 m³, and Goesan-gun, 3,794,000 m³. The annual amounts available for the representative crops, compared to the amount of evapotranspiration, were 313.9% in Dangjin-si, 29.5% in Yesan-gun, 56.1% in Cheongyang-gun, and 20.1% in Goesan-gun.

• Journal of The Geomorphological Association of Korea
• /
• v.23 no.1
• /
• pp.87-101
• /
• 2016

This study was conducted to develop a hydrological model of catchment water balance which is able to estimate irrigation return flows, so BROOK90-K (Kongju National University) was developed as a result of the study. BROOK90-K consists of three main modules. The first module was designed to simulate water balance for reservoir and its catchment. The second and third module was designed to simulate hydrological processes in rice paddy fields located on lower watershed and lower watershed excluding rice paddy fields. The models consider behavior of floodgate manager for estimating the storage of reservoir, and modules for water balance in lower watershed reflects agricultural factors, such as irrigation period and, complex sources of water supply, as well as irrigation methods. In this study, the models were applied on Guryangcheon stream watershed. R2, Nash-Sutcliffe efficiency (NS), NS-log1p, and root mean square error between simulated and observed discharge were 0.79, 0.79, 0.69, and 4.27 mm/d respectively in the model calibration period (2001~2003). Furthermore, the model efficiencies were 0.91, 0.91, 0.73, and 2.38 mm/d respectively over the model validation period (2004~2006). In the future, the developed BROOK90-K is expected to be utilized for various modeling studies, such as the prediction of water demand, water quality environment analysis, and the development of algorithms for effective management of reservoir.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.48 no.2
• /
• pp.27-35
• /
• 2006

Large dams are managed with operation standard and flood forecasting systems, while small dams do not have management method generally. Shortage of water resources and natural disasters due to drought and flood raised public concerns for management of small dams. Most of small dams are irrigation dams, which need diversified water uses. However, the lack of systematic management of small dams have caused serious water wastage and increased natural disasters. Storage management method and system were developed to solve these problems in small dams. The system was applied to Seongju dam for effective management. The storage management method was established considering hydrology simulation and statistical analysis using the system. This method can bring additional available water, even in the same conditions of the water demand and the supply conditions of watershed. It can improve the flood control capacity and water utilization efficiency by' the flexible operation of storage space.

• Journal of Korea Water Resources Association
• /
• v.45 no.9
• /
• pp.929-941
• /
• 2012

In recent years, interest in river environment such as riparian landscape, water quality and ecological conservation has been growing with increasing recreation on agricultural river watershed. That caused the increase of necessity of water resources development, one of solutions for the diversification of agricultural water demand and shortages. In this respects, heightening irrigation dam, as a part of the 4-major river restoration project, is necessary to secure not only additional agricultural water but also instream flow for water quality improvement. However, operation plan of irrigation dam still not be clear. In this study, additional storage which secured through heightening irrigation dam was estimated using SWAT model. And instream flow effects on water quality of downstream were evaluated. The findings show that the additional water supply will contribute positively to water quantity and quality of downstream. The results show a 2~10% water quality improvement effect on nutrients, as well as an 1~8% water quantity increasing effect. In particular, additional storage can be effectively supplied from February to April by the reservoir operation. However, maintaining better water quality in irrigation reservoirs is important because the water quality of irrigation reservoirs can be negatively impacts the water quality in downstream of reservoirs.

• Journal of Korean Society of Rural Planning
• /
• v.23 no.1
• /
• pp.85-96
• /
• 2017

Existing agricultural reservoirs are considered as alternative source for the water welfare of rural area. In this study, domestic water supply potential of 476 reservoirs, which has storage capacity more than one million cubic meter, out of 3,377 agricultural reservoirs managed by Korean Rural Community Corporation (KRC) were investigated. Among them water quality of 136 reservoirs met the criteria of domestic water source which show less than COD 3 ppm. Available amount for domestic water of reservoirs, which meet the water quality, for ten year return period of drought was analyzed with reservoir water balance model. The results showed that 116 reservoirs has potential for supplementary domestic water supply while satisfying irrigation water supply. Finally, economic analysis using Net Present Value (NPV), Benefit-Cost (B/C) ratio, Internal Rate of Return (IRR), and Profitability Index (PI) methods was also conducted. The analysis showed that 19 reservoirs satisfied economic feasibility when water is provided from reservoir outlet but only 9 reservoirs meet the economic feasibility if water delivered from a reservoir to treatment plant by newly built conveyance canal. In order to supply the domestic water through the agricultural reservoirs managed by KRC, it is necessary to flexibly interpret and operate the 'Rearrangement of Agricultural and Fishing village Act'. Also, it is reasonable to participate in the water service business when there is a supply request from other Ministries. In addition, the KRC requires further effort to change the crop system for saving water and improve efficiency of irrigation systems.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.42 no.1
• /
• pp.57-65
• /
• 2000

The objective of this paper are to present a realistic methodology to estimate the daily water supply rates form irrigation pumping stattions, to validate it with the field data, and to report the daily irrigation pumping rates from the Han river basin. Five-year historical pumping records were collected from seventy-three pumping stations in the Han river basin. And the daily pumping rates were estimated from the electrical consumption records. The pumping patterns from the stations were analyzed and the results were applied to ungauged pumping stations in the basin. The method was appliedto five stations which were field monitored during the irragation periods in 1998. The relative errors between the observed and simulated water pumpage ranged from 1.4 to 7.0 percent. This indicates that the proposed method is valid to apply for estimating the pumping rates for agricultural lands. During 1993 to 1997, the annual average water pumpaging from the Han river and the tributaries were 350 million cubic meter. The annual water supply from the pumping stations varied from 973 to 1.377 mm in depth and the mean was 1,170 mm. The major factor affecting the annual variations was attributed to the rainfall during the growing seasons.

• Journal of agriculture & life science
• /
• v.45 no.6
• /
• pp.237-249
• /
• 2011

The purpose of this study was to monitor the streamflow of rural streams for investigating the status of stream depletion located downstream of irrigation reservoir. Bonghyun and Hi reservoirs area, located in Gyeongnam, Gosung-gun, Hi-myeon, were selected for study watersheds and streams. Streamflow monitoring were conducted 6 times during the paddy growing season of 2010 from May to October. Streamflow was measured for 18 stations downstream from two reservoirs with the interval of 300m to 500m, The amount of streamflow were highly dependent on the antecedent precipitation and irrigation amount. In most observation stations, streamflow was depleted when precipitation and irrigation were not provided. Pumping from stream for irrigation and water supply for factory and irrigation return flow were also factors on streamflow. Continuous monitoring for rural streams located in downstream of reservoirs are required to quantify the status of streamflow depletion and determine the amount of environmental flows.

• Journal of Korea Water Resources Association
• /
• v.42 no.4
• /
• pp.281-295
• /
• 2009

This study estimates the value of irrigation water in Korea using an economic programming model that is constructed with all the resource endowment constraints, technology restrictions and policy variables. The variability and uncertainty of water resource endowment are incorporated into the model through the chance-constrained technique. Solving the profit maximization problems with gradually reduced water endowments, we derive a series of shadow values of irrigation water. It has been found that uncertainty in water supply raises the damage from water loss, and the marginal damage increases in water loss.