• 한국농공학회논문집
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• 제57권1호
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• pp.59-67
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• 2015

Because reservoirs that supply irrigation water play an important role in water resource management, it is necessary to evaluate the vulnerability of this particular water supply resource. The purpose of this study is to provide water supply risk maps of agricultural reservoirs in South Korea using irrigation vulnerability model and cluster analysis. To quantify water supply risk, irrigation vulnerability indices are estimated to evaluate the performance of the water supply on the agricultural reservoir system using a probability theory and reliability analysis. First, the irrigation vulnerability probabilities of 1,346 reservoirs managed by Korea Rural Community Corporation (KRC) were analyzed using meteorological data on 54 meteorological stations over the past 30 years (1981-2010). Second, using the K-mean method of non-hierarchical cluster analysis and pre-simulation approach, cluster analysis was applied to classify into three groups for characterizing irrigation vulnerability in reservoirs. The morphology index, watershed area, irrigated area, and ratio between watershed and irrigated area are selected as the clustering analysis parameters. It is suggested that the water supply risk map be utilized as a basis for the establishment of risk management measures, and could provide effective information for a reasonable decision making on drought risk mitigation.

• 한국농공학회지
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• 제42권3호
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• pp.66-75
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• 2000

Effect of reclaimed sewage on the paddy rice culture was examined by field experiment for two consecutive years. The domestic sewage was treated by the constructed wetland and the effluent of the treatment wetland was used for irrigation water. The reclaimed sewage was diluted before irrigation in the first year and it was used without dilution in the second year experiment. Growth components and yields were compared against the control plot where conventional method was applied. And also soil characteristics of the plots before and after reclaimed sewage irrigation were analyzed Generally addition of the reclaimed sewage irrigation didn't affect paddy rice culture adversely and even enhancement was observed. Fertilization was thought to be important factor for rice culture rather than irrigation water quality. Conventional fertilization and reclaimed sewage irrigation which contained high nutrient concentration resulted in better growth and more yield. Unlike widespread concern lodging did not happen even in the case of irrigation with average 90mg/L of T-N and conventional fertilization. Soil characteristics changed after irrigation and significant EC increasing was observed for the reclaimed sewage irrigation plots. From soil analyses salt accumulation could be a more potential problem than nutrients like nitrogen and phosphorus in the use of reclaimed sewage irrigation. Overall reclaimed sewage irrigation was thought to be one of practical alternatives for the ultimate disposal of sewage in rural area.

• 한국농공학회논문집
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• 제53권6호
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• pp.101-109
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• 2011

The purpose of this study was to establish the methodology for providing the environmental flows from irrigation reservoir. Reservoir water budget for study area was analyzed to simulate the water supply scenarios for environmental flows. Bonghyun and Hi reservoirs area, located in Gyeongnam, Gosung-gun, Hi-myeon, were selected for study watersheds and streams for this study. Reservoir operation was simulated to determine the envionmental flows supply amount from March to October with the constraint that environmental flow supply was restrained when the storage of reservoir were below the half or one-third of effective storage. The simulated results indicated that the supply of environmental flows with the amount of 200 ton/day and 600 ton/day resulted in up to 15 mm and 29 mm of runoff depth increase in the downstream, respectively. The effect of environmental flows supply from existing irrigation reservoir was not significant because the irrigation reservoir was not designed to supply the environmental flows. It is necessary to remodel the irrigation reservoir and develop the reservoir operation technique, to meet the need for the environmental flows.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.212-218
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• 1996

The concrete pipe used to distribute irrigation water to the right place now available is commonly made up of cement , sand, earth, pebble, etc. These materials with right ratio and right amount of water were mixed and squeezed through the pipe-making machine called vertical squeezed pipe-making machine, and then a cement prefabricated pipe is produced . This kinds of pipe has been expanding by leaps and bounds. Being little cement contents and low cost, the length of pipe is 1.0m or so with weight of 50kg, which is easy to be made and to be transported. The demolish pressure of it is 0.2 MPa or so, which meets the needs of agriculture irrigation . The buried pipe irrigation system, has been popularized in Jining Municipal , Shandong Province. By the year of 1995 , the irrigation area under pipe conveyancesystem usign this type of pipe has reached 74000 hectares. By calculation, about 27.7million ㎥ water, 2.88 million kWh power , 0.167 million man power and 1528 hectares cu tivated land will be saved one year, adding value of agriculture output increased by 10 million kg. The total economic benefits amount to 0.92 million US$ a year. The paper presents the pipe making course and its application on a large scale area.

• 한국농공학회논문집
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• 제63권4호
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• pp.23-32
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• 2021

For agricultural water management, it is essential to establish the digital infrastructure data such as agricultural watershed, irrigated area and canal network in rural areas. Approximately 70,000 irrigation facilities in agricultural watershed, including reservoirs, pumping and draining stations, weirs, and tube wells have been installed in South Korea to enable the efficient management of agricultural water. The total length of irrigation and drainage canal network, important components of agricultural water supply, is 184,000 km. Major problem faced by irrigation facilities management is that these facilities are spread over an irrigated area at a low density and are difficult to access. In addition, the management of irrigation facilities suffers from missing or errors of spatial information and acquisition of limited range of data through direct survey. Therefore, it is necessary to establish and redefine accurate identification of irrigated areas and canal network using up-to-date high resolution images. In this study, previous existing data such as RIMS (Rural Infrastructure Management System), smart farm map, and land cover map were used to redefine irrigated area and canal network based on appropriate image data using satellite imagery, aerial imagery, and drone imagery. The results of the building the digital infrastructure in rural areas are expected to be utilized for efficient water allocation and planning, such as identifying areas of water shortage and monitoring spatiotemporal distribution of water supply by irrigated areas and irrigation canal network.

• Weed & Turfgrass Science
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• 제3권2호
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• pp.130-136
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• 2014

Tall fescue is commonly well-adapted for low maintain area because of its wear resistance, deep root system, and drought tolerances. Deep and infrequent irrigation refers to applying large amounts of irrigation, 1.3 to 2.5 cm or more, in a single irrigation event. Light and frequent irrigation is commonly used with small amounts of water, 0.3 to 0.6 cm, every day or every other day. N use for turfgrass management is often unnoticed for water management. The objective of this field study was to evaluate the effects of irrigation frequency and N rates for tall fescue growth. The three irrigation treatments were no irrigation (precipitation only), 0.5 cm applied every other day, and 1.8 cm applied once a week at one irrigation event. The nitrogen (N) treatments were the low, medium, and high N rate treatments. The low, medium, and high N treatments were applied over 2, 4, and 6 applications, respectively. If high main maintenance of tall fescue is not important and water source is limited, irrigation is not necessary and, the $9.8gNm^{-2}yr^{-1}$ of two applications can be recommended for tall fescue under the weather condition of the study.

• 농업과학연구
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• 제31권1호
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• pp.53-75
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• 2004

This study is aimed at identifying the national economic value of the irrigation facilities by reviewing the existing papers on economic values of the irrigation facilities and presenting current status of dual O & M problems of the irrigation facilities. This study suggested the unified O & M system rather than continuing the existing dual O & M system of irrigation facilities based on the surveyed results of the activities of irrigation fraternities in Chungnam Province. The findings and proposals for the successful unified and mono O & M system of the irrigation facilities are as follows: (1) Total number of irrigation facilities in the nation accounts for 67,582, while the total length of irrigation and drainage canals amounted to about 174,259km. On account of the total length of structural canals was estimated at 31%, much losses of water and much O & M costs have been inevitable for the full irrigation rice culture. In spite of the past heavy investment for irrigation facilities, the ratio of rain-fed and partially irrigated paddy fields accounts for 23% in 2003. Both Korea Agricultural and Rural Infrastructure Corporation (KARICO) and the city and Gun Governments have managed the irrigation facilities separately by irrigation fraternities. The KARICO have commanded 59% of irrigation paddy area with 18% of the total irrigation facilities, while the city and Gun governments covered 41% of irrigation paddy area with 82% of the existing number of irrigation facilities representing small and medium scale. (2) The 1999 demand prices of irrigation water per ton expressed in 2000 constant market price was estimated at 388 won, the supply price was amounted to 184 won per ton. Considering the supply and demand curve of the irrigation water, the existing irrigation facilities could not satisfy the demand of irrigation water. (3) In 1999, total present added value of the irrigation facilities during the economic life accounted for 48 trillion won, while total supply cost was 44.7 trillion won. The marginal benefit and cost ratio of irrigation water was 1.08. (4) The total O & M cost per year amounting to 681.1 billion won have been required to maintain and repair the existing irrigation facilities in Korea. For the successful unified O & M of irrigation facilities covering whole irrigated paddy field in Korea, 950 billion won of O & M costs are required to keep up the marginal benefit of irrigation water as 2,800 billion won per year. The total O & M cost as 950 billion won should be allocated 40%, 380 billion won for O & M costs of irrigation facilities and 60%, 570 billion won for improvement of irrigation facilities. (5) The study investigated and reviewed the present O & M status of the irrigation facilities by small and medium irrigation fraternities. Most of the farmers belong to the irrigation fraternities preferred not only unified O & M but also KARICO take-over of the whole O & M activities of the irrigation facilities. The prevailing O & M cost per 10a expended by the Corporation was amounted to 104,890 won, while that of city and Gun governments was only amounted to 4,600 won per 10a. regarding the small amount of O & M cost expended by city and Gun governments, it is evident that the existing irrigation system have been managed ineffectively and deteriorated the facilities comparing that of KARICO. In conclusion, the Government could not satisfied the demand of irrigation water by suppling water with existing irrigation facilities. Therefore new additional investment and financial support for irrigation water development should be made to convert rain-fed and partially irrigated paddy fields into fully irrigated ones. The operation and maintenance cost should be supported to keep the marginal values of rice production of existing irrigation facilities in the national economy and to modernize the obsolete irrigation facilities. By unifying the existing dual O & M systems, all the farmers belong to the irrigated paddy fields have to be equally benefited and could be increased their farm income and be stabilized their rural lives.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.164-175
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• 2019

The Tor Tong Daeng Irrigation Project with the irrigation area of 61,400 hectares is located in the Ping Basin of the Upper Central Plain of Thailand where farmers depended on both surface water and groundwater. In the drought year, water storage in the Bhumipol Dam is inadequate to allocate water for agriculture, and caused water deficit in many irrigation projects. Farmers need to find extra sources of water such as water from farm pond or groundwater as a supplement. The operation of Bhumipol Dam and irrigation demand estimation are vital for irrigation water allocation to help solve water shortage issue in the irrigation project. The study aims to determine the smart dam operation system to mitigate water shortage in this irrigation project via introduction of machine learning to improve dam operation and irrigation demand estimation via soil moisture estimation from satellite images. Via ANN technique application, the inflows to the dam are generated from the upstream rain gauge stations using past 10 years daily rainfall data. The input vectors for ANN model are identified base on regression and principal component analysis. The structure of ANN (length of training data, the type of activation functions, the number of hidden nodes and training methods) is determined from the statistics performance between measurements and ANN outputs. On the other hands, the irrigation demand will be estimated by using satellite images, LANDSAT. The Enhanced Vegetation Index (EVI) and Temperature Vegetation Dryness Index (TVDI) values are estimated from the plant growth stage and soil moisture. The values are calibrated and verified with the field plant growth stages and soil moisture data in the year 2017-2018. The irrigation demand in the irrigation project is then estimated from the plant growth stage and soil moisture in the area. With the estimated dam inflow and irrigation demand, the dam operation will manage the water release in the better manner compared with the past operational data. The results show how smart system concept was applied and improve dam operation by using inflow estimation from ANN technique combining with irrigation demand estimation from satellite images when compared with the past operation data which is an initial step to develop the smart dam operation system in Thailand.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.827-831
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• 2008

In this study, the effects of reclaimed wastewater irrigation on the concentration of heavy metals such as lead, zinc, cadmium, and copper in soil and vegetables were investigated by monitoring an experimental area irrigated with reclaimed wastewater. Three treatments and three replications on $10{\times}2$-m plots were installed and heavy metal concentrations in soil and vegetables were monitored from 2005 to 2007. The treatments applied in this study were groundwater irrigation (control treatment), wastewater irrigation, and irrigation with filtered reclaimed wastewater treated with ultraviolet light. The monitored results showed that the concentrations of Cu, Cd, and Pb in soil during the experimental period were lower than initial soil levels before irrigation, whereas Zn increased in all treatment plots. However, the ranges of Zn, Cu, Cd and Pb in soil were below the soil pollution standards in the Republic of Korea. Heavy metal concentrations in vegetables showed insignificant variations for all treatments.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.527-532
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• 1998

The inflow and outflow loads of T-N and T-P from a paddy field area during the irrigation period were investigated. For the concentration of T-N and T-P, surface water in paddies showed highest among irrigation water, drainage water and percolation water. For T-N, the average concentration of drainage water is higher than that of irrigation water before middle of June but is lower since. It is shown that the L(load)-Q (discharge) equation of T-N has high correlation for irrigation water, but the L-Q equation of T-P has high correlation for drainage water.