• Title, Summary, Keyword: Water demand estimation

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Development of the Estimation System for Agricultural Water Demand (농업용수 수요량 산정 시스템 개발(관개배수 \circled1))

  • 이광야;김선주;김현영;서영제
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • pp.114-119
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    • 2000
  • To estimate Agricultural water demand, many factors such as weather, type of crop, soil, cultivation method, crop coefficient and cultivation area, etc. must be considered. But it is not easy to estimate water demand in consideration of these many factors, which are variable according to a period and regional environment. So, this study provides estimation system for agricultural water demand(ESAD) in order to estimate water demand easily and accurately, calculates the present and future agricultural water demand and arranges all factors needed for water demand estimation. This study calibrates the application of estimation system for agricultural water demand with the data observed in the other Studies and analyzes agricultural water demand nationwide.

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Development of the Estimation System for Agricultural Water Demand (농업용수 수요량 산정 시스템 개발)

  • 이광야;김선주
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.43 no.1
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    • pp.53-65
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    • 2001
  • To estimate agricultural water demand, many factors such as weather, crops, soil, cultivation method, crop coefficient and cultivation area, etc. must be considered. But it is not easy to estimate water demand in consideration of these factors, which are variable according to growth stage and regional environment. This study provides estimation system for agricultural water demand(ESAD) in order to estimate water demand easily and accurately, and arranges all factors needed for water demand estimation. This study identifies the application of estimation system for agricultural water demand with the data observed in the other studies, and analyzes nationwide agricultural water demand. The results are as follows. 1) The practice of different rice cultivation in the paddy field resulted in different water demands. Water depth and infiltration ratio in paddy are the most important factors to estimate water demand. The water depths in paddy simulated by ESAD is very similar to the observed ones. 2) Water demand of upland crops varies with the crops, soil, etc.. Effective rainfall estimated by daily routing of soil moisture varies according to the crops, soil, and effective soil zone(root depth). As crop root become grown, effective rainfall and an amount of irrigation water has been increased. 3) The current unit water demand of upland crops applied as 500mm or 550mm to estimate water demand does not reflect the differences caused by the crops, regional surrounding, weather condition, etc. Results from ESAD for the estimation of water demand of upland crops show that ESAD can simulate the actual field conditions reasonably because it simulates the actual irrigation practices with the daily routing of soil moisture.

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Modeling Procedure to Adapt to Change of Trend of Water Demand: Application of Bayesian Parameter Estimation (물수요의 추세 변화의 적응을 위한 모델링 절차 제시:베이지안 매개변수 산정법 적용)

  • Lee, Sangeun;Park, Heekyung
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.2
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    • pp.241-249
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    • 2009
  • It is well known that the trend of water demand in large-size water supply systems has been suddenly changed, and many expansions of water supply facilities become unnecessary. To be cost-effective, thus, politicians as well as many professionals lay stress on the adaptive management of water supply facilities. Failure in adapting to the new trend of demand is sure to be the most critical reason of unnecessary expansions. Hence, we try to develop the model and modeling procedure that do not depend on the old data of demand, and provide engineers with the fast learning process. To forecast water demand of Seoul, the Bayesian parameter estimation was applied, which is a representative method for statistical pattern recognition. It results that we can get a useful time-series model after observing water demand during 6 years, although trend of water demand were suddenly changed.

A study on the prediction of the generation of domestic sewage by improvement of water demand estimation (생활용수 수요추정방법 개선에 의한 하수발생량 예측에 관한 연구)

  • 김재윤
    • Journal of Environmental Science International
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    • v.11 no.12
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    • pp.1275-1279
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    • 2002
  • This study was performed to improve water demand estimation and analize correlation between generation of domestic sewage and domestic water use. To improve the prediction of water demand estimation, new water demand equation was developed. The results is as follows. $InQ_t = {\beta}_0+{\beta}_1InP_t+{\beta}_2InY_t+{\beta}_3InH_t+{varepsilon}_t$By using the statistical analysis of the "generation of domestic sewage" and "domestic water use", the regression equation between them is formed. The result is as follows. Generation of domestic sewage : 0.8487 $\times$ Domestic water use + 684.57 ($R^2$= 0.972)>$R^2$= 0.972)

Bhumipol Dam Operation Improvement via smart system for the Thor Tong Daeng Irrigation Project, Ping River Basin, Thailand

  • Koontanakulvong, Sucharit;Long, Tran Thanh;Van, Tuan Pham
    • Proceedings of the Korea Water Resources Association Conference
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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.

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Consideration of Techniques for Agricultural Water Demands Estimation (농업용수 수요량 예측기법 고찰)

  • Park, Jae-Heung;Lee, Yong-Jig
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • pp.37-40
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    • 2002
  • It is to show the problems of the existing techniques to estimate agricultural water demand and to suggest the new methods considering the water demand for non-irrigated area and decrease of water loss in canal. It is to suggest the methods to improve the techniques for estimating agricultural water demand and to analyze the water demand and supply according to the facilities capacity. Until now, the concept of per the unit used to estimate agriculture water demand is useful to estimate demand, but is insufficient to cope with the variations of conditions in future. And the paddy area of government is not realistic against a trend of decrease. Water demand decrease is caused by constructions of irrigation facilities as constructing of irrigation canal, but application loss ratio is fixed. Increase of the water demand owing to the increase of the yield per the unit area is also the actual condition which is not considered. The guide-line must contain these contents for a demand estimate.

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Estimation of Paddy Water Demand Using Land Cover Map in North Korea (토지피복도를 이용한 북한 지역의 논용수 수요량 추정)

  • Yu, Seung-Hwan;Yun, Seong-Han;Hong, Seok-Yeong;Choe, Jin-Yong
    • KCID journal
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    • v.14 no.2
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    • pp.236-244
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    • 2007
  • Agricultural water demand in North Korea must be considered for the near-future investment in agricultural consolidation projects and to prepare for the future unification. Thus, the objective of this study is to estimate the agricultural water demand of paddy fieldss in North Korea. GIS data including land cover classification map, Thiessen network and administration maps of North Korea, and meteorological data were synthesized. In order to estimate paddy water demand for a 10-year return period, the FAO Blaney-Criddle method and the fixed effective rainfall ratio method were used. The results showed that 4.77 billion $\beta$(c)/year paddy water demand is required for the 512,400 ha of paddy fieldss. Paddy water demand in the three major regions - Hwanghaedo, Pyeongando, Hamgyeongnamdo - was estimated chargong 81.7 percent of total paddy water demand in North Korea.

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Estimation of Agricultural Water Demand in Hwanghae South Province, North Korea (북한 황해남도지역 농업용수 수요량의 추정(관개배수 \circled2))

  • 장민원;정하우
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • pp.175-180
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    • 2000
  • The purposes of this study were to determine an algorithm for estimating agricultural water demand of remote sites using remote sensing data and to apply it to Hwanghae South Province and estimate the present and potential water demand for agriculture use. 3 Landsat-5 TM images and DEM(100${\times}$100mm) were used for classification of the existing land cover and land suitability analysis for paddy fields. Also, 20 years meteorological data of North Korea were used for calculating the potential evapotranspiration by Blaney-Criddle eq. and net water demand. The results showed that the present and potential agricultural water demand and the developable area for paddy fields is about 89,300㏊.

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Estimation of Agricultural water demand considering multi-wide water supply system - On irrigation area of Sumjingang-dam - (광역 용수계통을 고려한 농업용수 필요수량의 산정 - 섬진강댐 수혜구역을 중심으로 -)

  • Moon, Jong-Won;Chung, Jin-Ho;Jang, Jung-Seok
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • pp.423-426
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    • 2003
  • The purpose of this paper is to estimate Agricultural water demand at irrigation area of sumjin reservoir, the Dongjin River basin, which consist of multi-wide water supply system and complicated irrigation channel and supplementary irrigation facilities.

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Estimation of the Reliability of Water Distribution Systems using HSPDA Model and ADF Index (HSPDA 모형 및 ADF index를 이용한 상수관망의 신뢰도 산정)

  • Baek, Chun-Woo;Jun, Hwan-Don;Kim, Joong-Hoon
    • Journal of Korea Water Resources Association
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    • v.43 no.2
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    • pp.201-210
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    • 2010
  • In this study, new methodology to estimate the reliability of a water distribution system using HSPDA model is suggested. In general, the reliability of a water distribution system can be determined by estimating either the ratio of the required demand to the available demand or the ratio of the number of nodes with sufficient pressure head to the number of nodes with insufficient pressure head when the abnormal operating condition occurs. To perform this approach, hydraulic analysis under the abnormal operating condition is essential. However, if the Demand-Driven Analysis (DDA) which is dependant on the assumption that the required demand at a demand node is always satisfied regardless of actual nodal pressure head is used to estimate the reliability of a water distribution system, the reliability may be underestimated due to the defect of the DDA. Therefore, it is necessary to apply the Pressure-Driven Analysis (PDA) having a different assumption to the DDA's which is that available nodal demand is proportion to nodal pressure head. However, because previous study used a semi-PDA model and the PDA model which had limited applicability depending on the characteristics of a network, proper estimation of the reliability of a water distribution system was impossible. Thus, in this study, a new methodology is suggested by using HSPDA model which can overcome weak points of existing PDA model and Available Demand Fraction (ADF) index to estimate the reliability. The HSPDA can simulate the hydraulic condition of a water distribution system under abnormal operating condition and based on the hydraulic condition simulated, ADF index at each node is calculated to quantify the reliability of a water distribution system. The suggested model is applied to sample networks and the results are compared with those of existing method to demonstrate its applicability.