• Journal of Soil and Groundwater Environment
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• v.24 no.5
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• pp.17-30
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• 2019

Intensive agricultural development in Mexicali valley, Baja-California, Mexico, has induced tremendous strain on the limited water resources. Agricultural water consumption in the valley mainly relies on diversions of the Colorado River, but their water supply is far less than the demand. Hence, the use of groundwater for irrigation purposes has gained considerable attention. To account for these changes, it is important to evaluate surface water and groundwater conditions based on historical water use. This study identified the effects of agricultural activities on groundwater levels and groundwater recharge in the Mexicali valley (in irrigation unit 16) by a comprehensive MODFLOW Farm process (MF-FMP) numerical modeling. The MF-FMP modeling results showed that the water table in the study area is drawn downed, more in eastern areas. The inflow-outflow analysis demonstrated that recharge to the aquifer occurs in response to agricultural supplies. In general, the model provides MF-FMP simulations of natural and anthropogenic components of the hydrologic cycle, the distribution and dynamics of supply and demand in the study area.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.2
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• pp.3-12
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• 2005

The objective of this study is securement of upland irrigation water using storage level management of small dams. However, it is not new development of water resources but securement of water using storage level management of existing dam. This study has enhanced the water utilization coefficient of dam, after extra available water had been calculated by application of periodical management storage level and this water is used to other water like the upland irrigation water demand. As the result of application, it can secure extra available water except the water requirement. Minimum extra available water except flood is about $20,000,000\;m^3$ and crop irrigation water demand of 10yr frequency is about $2,033,000\;m^3$ in Seongju. The utilization of crop irrigation water can be possible. And extra available water is about $3,102,000\;m^3$ in 2000, $1,959,000\;m^3$ in 2001 except flood period and crop irrigation water demand of 10yr frequency is about $2,272,000\;m^3$ in Donghwa. It is judged that extra available water cannot be used to crop irrigation water during the dry season in Dongwha. Consequently, when management storage level is determined and more efficient use of water is gotten like this study, water utilization coefficient will be enhanced.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.120-125
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• 2000

This study analyzes agricultural water demand nationwide which calculated by the estimation system for agricultural water demand(ESAD) with the data are observed in the other Studies. The results are as follows. Maximum, minimum and average values of annual evapotranspiration in paddy in 1,767 boundaries covering all the country are estimated as 819.2mm, 595.2mm and 702.9mm respectively. In the case of transplant seeding, the annual effective rainfall is estimated as 834.7mm to 464.3mm, while the average is 635.3mm. The amount of effective rainfall is largest in case of transplant seedlings and then come watered direct seeding and dry direct seeding regardless of region. Maximum, minimum and average values of annual evapotranspiration in upland in 1,767 boundaries are estimated as 659.97mm, 129.3mm and 411.8mm respectively. The annual effective rainfall is estimated as 607.2mm to 68.3mm while the average is 257.4mm. infiltration ratio in paddy in 1,767 boundaries applied in ESAD is 5.06mm/day in average, varying from 12.0mm/day to 2.0mm/day. Applied conveyance loss is 12.8% in average, varying from 18.0% to 8.0%.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.318-323
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• 2005

This research evaluates agricultural water supply capabilities for water computing demand and supply for water of the whole water system of Ansung stream by carrying out basin water balance classified by irrigation facility of water system of Ansung stream.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.41-44
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• 2002

It is unreasonable to calculate the amount of agricultural water use by applying unit demand method, because it is different from other water use due to the return flow and reuse in the recycle of watershed. Data from irrigation pumping station and reservoir were analysed. Factors for water balance are precipitation, evapotranspiration, percolation, runoff, and management loss, etc. Here in the study, the amount of agricultural water was defined in the way of three different categories. First one is "Gross water" including evapotranspiration, percolation, and management loss. Second one is "Agricultural water" including Gross water and effective rainfall. Third one is "Broad water" which is abstracting the return flow from Agricultural water.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.193-202
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• 2022

The recurrent neural network (RNN) algorithm has been widely used in water-related research areas, such as water level predictions and water quality predictions, due to its excellent time series learning capabilities. However, studies on water quality predictions using RNN algorithms are limited because of the scarcity of water quality data. Therefore, most previous studies related to water quality predictions were based on monthly predictions. In this study, the quality of the water in a reservoir in Nonsan, Chungcheongnam-do Republic of Korea was predicted using the RNN-LSTM algorithm. The study was conducted after constructing data that could then be, linearly interpolated as daily data. In this study, we attempt to predict the water quality on the 7th, 15th, 30th, 45th and 60th days instead of making daily predictions of water quality factors. For daily predictions, linear interpolated daily water quality data and daily weather data (rainfall, average temperature, and average wind speed) were used. The results of predicting water quality concentrations (chemical oxygen demand [COD], dissolved oxygen [DO], suspended solid [SS], total nitrogen [T-N], total phosphorus [TP]) through the LSTM algorithm indicated that the predictive value was high on the 7th and 15th days. In the 30th day predictions, the COD and DO items showed R² that exceeded 0.6 at all points, whereas the SS, T-N, and T-P items showed differences depending on the factor being assessed. In the 45th day predictions, it was found that the accuracy of all water quality predictions except for the DO item was sharply lowered.

• Magazine of the Korean Society of Agricultural Engineers
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• v.33 no.4
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• pp.45-51
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• 1991

The objective of this paper is to show how the fuzzy sets theory can be applied to the reservoir operation guidelines for agricultural purposes. The concepts of the theory has been resented as a new tool for the decision problems which contains fuzziness and it's application can be found in operations research, expert systems, robotics, fuzzy computers, and pattern recognition. The fuzzy control system for the reservoir operation composed of a set of reservoir operation rules and a fuzzy inference engine was built. Water demand for paddy fields, water availability, and inflow to a reservoir were selected as main factors which determine the magnitude of reservoir release. The behavior of the control system was evaluated for different level of water demand and the results seemed to be reasonable.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.485-485
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• 2018

Rainwater harvesting system (RWH) can provide a relief for the household and farmers especially in areas with intense water scarcity during the long lull of rainy season. However, much attention has not been given to this alternative water source in Nigeria. This paper estimates the per capita water demand for 1,950 inhabitants and rainwater potential in Ojonbodu Estate, Oyo State, Nigeria, using data from detailed questionnaires, water consumption calculator software, and 20-year rainfall data. The potential rainwater estimation was based on amount of precipitation, size of catchment and runoff coefficient. Consequently, using estimated values of $39420m^3$ and $6.5114{\times}10^7m^3$ for per capita consumption and potential rainwater respectively, the rainwater harvesting system was designed for rainwater collection, and storage. The harvested rainwater was $450, 000m^3$ with collection efficiency of 69.16 %, which exceeded the household water consumption requirement. Thus, the harvested rainwater was able to meet the estimated water demand of the Ojonbodu Estate households during the period of water scarcity.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.5
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• pp.83-92
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• 2001

As a result of the recent water resources crisis, development of water management automation system becomes important. This system should be developed with open architecture in order to flexibly meet the spacial and time change of irrigation water demand. Thereby, water management automation system requires open architecture and suitable software program. This study presents an application of object-oriented methodology for Open Water Management Program(OWMP). Accordingly, OWMP provides a high degree of reliability which allows modification of parameters by change of region or time to be possible. OWMP consists of Data Base Management System(DBMS) and Model System. DBMS makes it possible to analyze data related with planning water schedule and establishing database. Model System calculates reservoir inflow, reservoir effluent and basin water demand. An operator decides the reservoir operation with results of Model System and DBMS. OWMP could be adapted to the planning and decision for saving water.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.2
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• pp.37-46
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• 2012

The change of rainfall pattern and hydrologic factors due to climate change increases the occurrence probability of agricultural reservoir water shortage. Water supply assessment of reservoir is usually performed current reservoir level compared to historical water levels or the simulation of reservoir operation based on the water budget analysis. Since each reservoir has the native property for watershed, irrigation district and irrigation water requirement, it is necessary to improve the assessment methods of agricultural reservoir water capability about water resources system. This study proposed a practical methods that water supply vulnerability assessment for an agricultural reservoir based on a concept of probabilistic reliability. The vulnerability assessment of water supply is calculated from probability distribution of water demand condition and water supply condition that influences on water resources management and reservoir operations. The water supply vulnerability indices are estimated to evaluate the performance of water supply on agricultural reservoir system, and thus it is recommended a more objective method to evaluate water supply reliability.