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1
Fox, Fred Andrew 1956. "Irrigation scheduling decision support." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/288770.
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Irrigation scheduling using the soil water balance approach has been recommended to irrigators for many years. Reasonably good results are normally obtained by researchers using carefully quantified inputs. Irrigators in production agriculture may estimate inputs and then question the validity of the method when the irrigation recommendations conflict with present irrigation schedules. By associating each input with an interval representing possible bias based on the way the input was estimated, and solving the irrigation scheduling model using the intervals as inputs, the output was associated with an interval representing possible bias. This method was also used to evaluate possible bias associated with growing degree day based crop coefficient curves developed from Arizona crop consumptive use measurements. For comparison purposes, roughly estimated inputs based on irrigation system type, soil type, area weather data and available crop coefficient curves were used as default intervals. Improved input intervals consisted of observed irrigation system performance, soil property measurements, local weather data and theoretical improvements in crop coefficient curves. For surface irrigation, field observation of plant stress and soil water content showed the greatest potential to improve irrigation date predictions. For buried drip under a row crop, accuracy of the predicted daily irrigation rate was most improved by a better estimate of irrigation efficacy.
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Didan, Kamel 1965. "Expert system for drip irrigation design." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/291460.
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Drip irrigation design is a multi-step routine that has to be carried out in a step by step fashion with each step covering a part of the design process. An expert system has been developed with a set of external programs to accomplish the drip system design. The expertise used in the present expert system knowledge base was induced from engineering handbooks and articles as well as personal consultations. The expert system has been developed in such a way that a variety of cases can be handled. In addition, to simulate the human expert, a new drip irrigation design evaluation factor has been introduced (Design Success Indicator, DSI) in order to estimate the system response on field depending on the confidence of data being used. The results are very promising with respect to the expertise used. However many parts of the knowledge-base have to be fine-tuned in order to reach a highly performing expert system.
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Andriyas, Sanyogita. "Analysis of Irrigation Decision Behavior and Forecasting Future Irrigation Decisions." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1359.
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Farmers play a pivotal role in food production. To be economically successful, farmers must make many decisions during the course of a growing season about the allocation of inputs to production. For farmers in arid regions, one of these decisions is whether to irrigate. This research is the first of its kind to investigate the reasons that drive a farmer to make irrigation decisions and use those reasons/factors to forecast future irrigation decisions. This study can help water managers and canal operators to estimate short-term irrigation demands, thereby gaining information that might be useful in management of irrigation supply systems. This work presents three approaches to study farmer irrigation behavior: Bayesian belief networks (BBNs), decision trees, and hidden Markov models (HMMs). All three models are in the class of evolutionary algorithms, which are often used to analyze problems in dynamic and uncertain environments. These algorithms learn the connections between observed input and output data and can make predictions about future events. The models were used to study behavior of farmers in the Canal B command area, located in the Lower Sevier River Basin, Delta, Utah. Alfalfa, barley, and corn are the major crops in this area. Biophysical variables that are measured during the growing reasons were used as inputs to build the models. Information about crop phenology, soil moisture, and weather variables were compiled. Information about timing of irrigation events was available from soil moisture probes installed on some agricultural fields at the site. The models were capable of identifying the variables that are important in forecasting an irrigation decision, classes of farmers, and decisions with single and multi-factor effect regarding farmer behavior. The models did this across years and crops. The advantage of using these models to study a complex problem like behavior is that they do not require exact information, which can never be completely obtained, given the complexity of the problem. This study uses biophysical inputs to forecast decisions about water use. Such forecasts cannot be done satisfactorily using survey methodologies. The study reveals irrigation behavior characteristics. These conform to previous beliefs that a farmer might look at crop conditions, consult a neighbor, or irrigate on a weekend if he has a job during the week. When presented with new data, these models gave good estimates for probable days of irrigation, given the past behavior. All three models can be adequately used to explore farmers' irrigation behavior for a given site. They are capable of answering questions related to the driving forces of irrigation decisions and the classes of subjects involved in a complex process.
4
Reynolds, Curt Andrew 1960. "Design and evaluation of bubbler irrigation systems." Thesis, The University of Arizona, 1993. http://hdl.handle.net/10150/291563.
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Low-head bubbler irrigation systems are particularly well-suited for the irrigation of orchard crops, and these systems differ from other micorirrigation systems because they are based on gravity-flow, can operate at pressures as low as 1 meter (3.3 ft), and do not require elaborate filtration systems. A design procedure for low-head bubbler systems is described in detail, and example designs for bubbler systems located on level ground and gradual slopes are also presented. The design procedure utilizes head loss gradient charts based on the Darcy-Weisbach equation to size the pipe diameters, and the delivery hose elevations are calculated by using a personal computer with spreadsheet software. The causes of air locks in the laterals and delivery hoses are also investigated, and minimum design flow rates for various pipe diameters are recommended to ensure flow velocities are high enough to prevent air locks from occurring within the delivery hoses.
5
De, Vries Tonny Tessa. "Irrigation scheduling with integer programming." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273891.
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Akhand, Md Nurul Alam. "A canal irrigation water allocation model." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185910.
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A water allocation model was developed to assist with allocation of canal water to competing crop irrigation demands. Multi-period linear programming was utilized to optimally allocate water in both time and space to maximize benefits for an irrigated farm. Irrigation scheduling, crop response and canal water delivery models were used to support the water allocation decisions. The irrigation scheduling model supplied information on crop evapotranspiration and soil water storage. The crop response model predicted crop yield in response to the irrigation water applications. The canal delivery model checked the feasibility of supplying the allocation quantities through the control structures and turnouts. The allocation model was evaluated by tests of water allocation for the University of Arizona, Maricopa Agricultural Center demonstration farm. In crop scenarios which emphasized cotton production, the model recommended deficit irrigation for the barley, cotton, grapes and wheat fields during periods when the quantity of irrigation water demanded was greater than that supplied. Analysis of the effects of changes in water cost and crop returns showed the basis of the solution remained unchanged for a wide range of data. The basis was, however, found to be unstable with very limited water supplies. In addition to serving as a planning tool, the allocation model could be used as a real time management tool. It is believed to have broad applicability to other irrigation projects in other areas with characteristics similar to Arizona test conditions.
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Hards, Adrian F. "Comparative engineering costing and implications of commercial and smallholder irrigator design for projects." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6501.
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Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2011.ENGLISH ABSTRACT: In the study, six irrigation schemes based in the Eastern Cape have been considered and evaluated, according to two levels of supply (LOS) of irrigation water. The two levels of supply are that of a commercial irrigator and that of a smallholder irrigator. The irrigation infrastructure for each of the six schemes was designed, and the associated costs determined, for each level of supply. The primary objective of the study is to determine the impact of infrastructure costs and irrigation areas on the target user, either the commercial or the smallholder irrigator. This is related directly to the assumption that lower water volumes are used by the smallholder irrigator. The study addresses the impact of different designs on the amount of water used, land utilised and resultant costs of the infrastructure. The initial capital costs and the on-going operational and maintenance costs (O&M) for each level of supply for each of the schemes have been calculated. The evaluation of the two LOS has shown that the capital cost for the commercial LOS is approximately 18 % higher than for the smallholder LOS and the O&M costs 6 % to 36 % higher. The schemes that were investigated can be grouped into five general scheme types. The first type is gravity schemes, which need rehabilitation, while the bulk supply is in place with no augmentation or rehabilitation required. The second is pumped scheme which is in need of rehabilitation, while the bulk supply is in place with no augmentation or rehabilitation required. The third type includes run-of-river schemes where water is abstracted and pumped directly to the lands. The fourth type includes run-of-river schemes where water is abstracted and pumped to storage. The fifth type is the gravity scheme where the bulk supply needs to be installed as part of the scheme. These types are then grouped and can be used to give guidance on the anticipated costs dependant on the scheme type and the required level of service. A further objective of the research is to determine the impact on the smallholder irrigators who find themselves on a commercial LOS system. This can be either on a scheme that has already been designed, or on a new system. The evaluation of the commercial under-utilised LOS and the smallholder LOS has shown that the commercial capital cost is 18 % higher and the O&M costs 5 % to 29 % higher. The study further aligns the estimated costs with the farmer typology providing a broader understanding of the design to be adopted for different levels of supply. This provides the linkage between farmer types, the design to be implemented and the anticipated costs thereof.
AFRIKAANSE OPSOMMING: As deel van hierdie narvorsing word ses verskillende besproeiingsskemas in die Oos-Kaap ten opsigte van twee voorsieningsvlakke ondersoek. Die twee voorsieningsvlakke ter sprake is vir ‘n kommersiële en kleinboerdery opset. Die besproeiingsinfrastruktuur is vir elk van die ses besproeiingsskemas ontwerp en ‘n kosteberaming vir elk van voorsieningsvlakke gedoen. Die hoofdoelwit van hierdie verslag is om te bepaal wat die impak van kostes en besproeiingsareas op beide kommersiële- en kleinboerderye is. Dit is direk gebaseer op die aanname dat kleinboerderye minder water gebruik. Die verslag ondersoek die impak van verskillende ontwerpe op waterverbruik, besproeiingsoppervlak benodig en die gevolglike infrastruktuurkostes. Die aanvanklike kapitaalkostes asook bedryfs- en onderhoudsuitgawes (B&O) vir elk van die voorsieningsvlakke, is vir elk van die besproeiingskemas bereken. Die resultaat van die ondersoek van die twee voorsieningsvlakke het aangetoon dat die kapitaalkoste van kommersiële besproeiingskemas 18 % hoër as die van kleinboerderye is, en bedryfs- en onderhoudsuitgawes 6 tot 36 % hoër. Die skemas wat ondersoek is, kan in vyf algemene skema tipes verdeel word. Die eerste is die gravitasieskemas wat rehabilitasie benodig terwyl die hooftoevoer in plek is met geen uitbreidings- of rehabilitasiebehoeftes. Die tweede is pompskemas wat rehabilitasie benodig terwyl die hooftoevoer in plek is met geen uitbreidings- of rehabilitasiebehoeftes. Die derde is rivierskemas waar besproeiingswater direk uit die rivier na die landerye gepomp word. Die vierde is rivierskemas waar besproeiingswater direk uit die rivier na a reservoir gepomp word. Die vyfde skema tipe is die gravitasieskemas waar die hooftoevoer ook gebou moet word as deel van die skema. Die skema tipes kan gebruik word om leiding te verskaf ten opsigte van verwagte skema kostes afhangende van die skema tipe en vereiste voorsieningsvlak. ‘n Verdere doelwit van die studie is om die impak op kleinboere te bepaal wat op ‘n kommeriële voorsieningsvlak boer. So ‘n stelsel kan ‘n gevestigde of nuwe stelsel wees. Die resultaat van die ondersoek van die onderbenutte kommersiële voorsieningsvlak en die kleinboerdery voorsieningsvlak het gewys dat die kapitaalkoste van kommersiële besproeiingskemas 18 % hoër as die van kleinboerderye is, en bedryfs- en onderhoudsuitgawes 5 tot 29 % hoër. Die verslag vereenselwig die verwagte kostes met die tipe boerdery en verskaf ‘n beter begrip van die tipe ontwerp wat elk van die voorsieningsvlakke benodig. Dit verskaf dus die verband tussen die tipe boerdery, die ontwerp benodig en die verwagte projekkostes.
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Kuntz, Lauren B. "Wick irrigation systems for subsistence farming." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/83726.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Department of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 59-61).
Irrigation on small-scale farms has been noted as a key method to help lift subsistence farmers out of poverty. With water scarity growing around the globe and lack of access to electricity still prevalent in rural areas, the need to develop an energy efficient irrigation system that simultaneous limits wasted water while being low cost is essential. The possibility of using a wicking irrigation system that relies on the suction plants create for water to mitigate the pumping pressure is investigated. A theoretical model for such a system is developed for an acre sized wicking irrigation system, and the power and water efficiency is compared to a standard drip irrigation system. While the wicking irrigation system has a greater distribution of water delivery from the wicks than compared to the dripper system, a wicking system has the potential to operate at much lower power, with the possibility of even being a power source. If a direct coupling could be developed between the plant's roots and wick, eliminating the need for water to travel through the soil, the energy benefit of the wicking system would be even more dramatic.
by Lauren B. Kuntz.
S.B.
9
Colaizzi, Paul Dominic 1968. "Overwatering controller for landscape irrigation systems." Thesis, The University of Arizona, 1997. http://hdl.handle.net/10150/278585.
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Water conservation in metropolitan areas of Arizona is critical if limited water resources are to meet current and future demands. Timer controlled landscape irrigation systems contribute to a large portion of municipal water use, and there is currently a great potential for water savings when deficit irrigation is practiced. Such systems tend to forfeit deficit irrigation by overwatering vegetation; however, deficit irrigation may be improved if the number of irrigation cycles are reduced based on sensing soil water in the plant root zone. A patent pending electronic circuit, called the overwatering controller, has been developed and tested for this purpose. Test results show the overwatering controller has great potential as a water conservation and deficit irrigation management tool.
10
Waheed, Syed Imran 1962. "Design criteria for low head bubbler irrigation systems." Thesis, The University of Arizona, 1990. http://hdl.handle.net/10150/291398.
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Analysis indicates that the Blasius equation yields accurate estimates of head loss in small diameter plastic tubing and larger diameter PVC pipe for Reynolds numbers upto 100,000. The Hazen-Williams equation with suitable roughness parameter values also predicts head loss accurately. The results of laboratory experiments reveal that the undulations which are created during field installation are the primary cause of air locking in the delivery hose. The additional head needed to release the trapped air was found to be equal to the sum of heights of all the undulations. If the sum of their heights exceeds the design head loss in the delivery hose, air locking will result. The capital investment for bubbler system under study was comparable to that of a pressurized drip system. Long term savings in terms of energy and maintenance make low head bubbler systems an attractive alternative to pressurized drip systems for irrigating orchards or vineyards.
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Agodzo, Sampson Kwaku. "Trickle irrigation using porous clay pot." Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.331989.
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Aladenola, Olanike. "Decision support system for irrigation water management." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=123181.
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Abstract Variability in seasonal precipitation, potential climate change impacts, competition for water among users, rising population and increasing food demands are putting pressure on agricultural water demands. For irrigated agriculture in Canada to play a major role in addressing current and future global food supply problems, more innovative and sustainable irrigation management approaches are required. In this context a decision support system that ensured more effective irrigation water allocation, application and optimisation was developed. Crop water requirements and irrigation schedules for bell pepper (Capsicum annuum L.) were obtained from greenhouse and field studies. Greenhouse experiments were conducted to determine appropriate irrigation water applications, agronomic and physiological response to water stress for peppers grown on clay and loamy sand soils. These studies involved four irrigation levels -120% (T120), 100% (T100), 80% (T80) and 40% (T40) of pan evaporation (Epan). The results showed that highest yields and water use efficiency were obtained with 120% Epan replenishment on loamy sand compared to clay soil. The corresponding crop water stress index (CWSI) at T120 was 0.18 to 0.20 on clay, and 0.09 to 0.11 on loamy sand. The fruit total soluble solids content was highest in the T40, and least in the T120 treatments.Given that the greenhouse results were obtained under controlled conditions, it was necessary to extend the research in the field. Experiments were conducted to determine the level of available soil water at which irrigation should be applied to prevent water stress and yield loss for peppers on a clay soil. Four irrigation thresholds, as a percentage of available water content, were investigated. These were: 85% (T1), 75% (T2), 50% (T3), and 25% (T4) available water content. A control of no irrigation (T5) was implemented. The crop water stress index (CWSI) and effects of elevated CO2 on the stomatal conductance and water applied were also investigated. The three CO2 levels studied were: ambient CO2 (~400 ppm), predicted CO2 for the year 2050 (550 ppm), and predicted CO2 for the year 2100 (750 ppm). Optimum marketable yields were achieved when 50% (T3) of the available water content had been depleted with a corresponding CWSI of 0.3 to 0.4. A decrease in stomatal conductance with increasing CO2 was observed. Irrigation water requirements decreased by 6-42% under elevated CO2 of 550 ppm, and 28-58% for elevated CO2 of 750 ppm. An integrated agricultural water demand model (IAWDM) was developed using a graphical user interface (GUI) in Matlab to estimate irrigation water requirements (IWR). A pre-requisite for the model development was to ensure that solar radiation (Rs) input data were of good quality. The suitability of nine (Rs) estimation methods, and their effects on reference evapotranspiration (ETo) were evaluated using data from eight weather stations across Canada. Based on Root mean square error (RMSE) of 1-6%, the Hargreaves and Samani (H-S) method gave best results for locations that did not have reliable, long term, observed Rs and sunshine duration data. Output from the IAWDM was compared with CROPWAT simulations, and metered irrigation water-use. IWR from IAWDM deviated from field data by 7 to 28%, while CROPWAT deviated by 7 to 42%. Future IWR was estimated using Agriculture and Agri-food Canada (AAFC) generated climate change data for 2040 to 2069. Results showed that IWR of bell peppers will increase by 19 to 27% in the future. A sensitivity analysis showed that IWR is most sensitive to air temperature, reference evapotranspiration (ETo), and crop coefficients, followed by solar radiation and precipitation.Overall the findings from this study led to a more sustainable greenhouse and field production of vegetable. The improved management practices increased irrigation water use efficiency thereby leading to a more beneficial use of agricultural water.L'imprévisibilité des présentes précipitations saisonnières et des répercussions potentielles du changement climatique, ainsi que les besoins alimentaires grandissants d'une population croissante, mènent à une compétition plus acharnée entre les utilisateurs des ressources en eau, imposant ainsi d'importantes pressions sur la demande en eau à fins agricoles. Pour que l'agriculture irriguée au Canada puisse contribuer de façon significative à la résolution de présents et futures problèmes d'approvisionnement alimentaire mondial, des modes de gestion d'irrigation plus innovateurs et durables sont nécessaires. Dans ce contexte, un système d'aide à la décision assurant une plus grande efficacité d'allocation, d'application et d'optimisation des eaux d'irrigation fut conçue. Les études en serre établirent un régime d'irrigation approprié pour les poivrons et notèrent leurs réponses agronomiques et physiologiques à des stress hydriques lorsque cultivés sur un sol argileux ou un sable loameux. Quatre niveaux d'irrigation furent évalués, soit 120% (T120), 100% (T100), 80% (T80) ou 40% (T40) de l'évaporation bac (Ebac). Un réapprovisionnement à 120% Ebac entraîna un rendement et une efficacité d'utilisation de l'eau plus élevés sur le sable loameux que sur le sol argileux. L'indice de stress hydrique (ISH) de la culture soumise au taux de réapprovisionnement de 120% fut de 0.18 à 0.20 sur le sol argileux, et de 0.09 à 0.11 sur le sable loameux. Comme les résultats en serre furent obtenus sous des conditions hautement contrôlées, il fut nécessaire d'étendre la recherche à une culture en champ. Une étude fut entreprise sur un sol argileux pour déterminer quel seuil de pourcentage d'eau disponible dans le sol (85%, 75%, 50%, ou 25%) devrait entraîner une irrigation visant à prévenir un stress hydrique du plant de poivron et la perte de rendement qui en suivrait. Un étalon n'ayant reçu aucune irrigation fut également inclus. L'indice de stress hydrique (ISH) fut suivi et l'effet de teneurs élevés en CO2 sur la conductance stomatique et la quantité d'eau devant être appliqué furent également étudiés. Les trois teneurs en CO2 évalués furent celles de l'air ambiant présent (~400 ppm), et les teneurs prédites pour 2050 et 2100 (550 et 750 ppm, respectivement). Un rendement commercialisable optimal fut obtenu avec un seuil d'irrigation représentant à une carence de 50% en eau disponible du sol, ce qui correspond à un indice de stress hydrique de 0.3 à 0.4. Par rapport aux besoins en irrigation sous la présente teneur en CO2 de l'air ambiant, ces besoins diminuèrent de 6 à 42% sous une teneur en CO2 de 550 ppm, et de 28 à 58% sous une teneur en CO2 de 750 ppm. Un modèle intégré de demande en eau pour fins agricoles (MIDEFA) permettant l'estimation des besoins en eau d'irrigation (BEI) fut élaboré en utilisant l'interface graphique de Matlab. L'élaboration du modèle nécessita des données d'entrée de radiation solaire (Rs) de haute qualité. Laquelle de neuf méthodes permettant d'estimer Rs conviendrait le mieux fut évalué en utilisant des données parvenant de huit stations météorologiques canadiennes. Avec une erreur quadratique moyenne de 1 à 6%, la méthode Hargreaves et Samani (H-S) donna les meilleurs résultats. Les données tirées du MIDEFA furent comparées à celles tirées de simulations avec CROPWAT, et aux données provenant d'un compteur d'eau utilisée à fins d'irrigation. Les différences entre le BEI mesuré au champ et ceux calculés par MIDEFA et CROPWAT furent de 7 à 28% et 7 à 42%, respectivement. De futures BEI furent estimés en utilisant des données fournies par Agriculture et Agroalimentaire Canada (AAC), reflétant le changement de climat prévu pour 2040 et 2069. Selon cette analyse, le BEI pour les poivrons augmenterait de 19 à 27% dans l'avenir.Dans l'ensemble les constats de notre étude ont mené à une production de légumes plus durable à la fois en serre et au champ.
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Maheepala, H. M. I. P. S. "Operation of secondary reservoirs in irrigation systems." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315630.
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Burton, Martin Anthony. "A simulation approach to irrigation water management." Thesis, University of Southampton, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357297.
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Ijir, Timothy Aondona. "The performance of medium scale jointly managed irrigation schemes in Sub-Saharan Africa : a study of the Wurno irrigation scheme, Nigeria." Thesis, University of Southampton, 1994. https://eprints.soton.ac.uk/361140/.
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The subject of `irrigation performance assessment' has grown in importance since the early 1970s. This has been as a result of the increasing realization that irrigation schemes around the world, particularly those in developing countries, do not live up to their expectations. There has therefore been an increasing interest in probing into the operations of existing irrigation schemes in order to understand their strengths and weaknesses, and to developing methodologies and indicators for performance assessment, with a view to improving their performance and water use efficiency. This study presents a conceptual methodology and performance indicators for evaluating the performance of medium scale irrigation schemes in Africa with joint participation between smallholder farmers and an irrigation agency. The proposed methodology provides a logical sequence of the main processes involved in irrigation performance assessment with emphasis on the 'whole system' or 'farming system' approach. Performance indicators have been proposed which relate to the inputs, processes of transformation, and outputs, which is a marked variation from existing approaches which focus only on the evaluation of outputs. The indicators describe qualitatively and quantitatively the level of attainment of the objectives of an irrigation scheme, or parts thereof. The methodology and concepts outlined in the first part of this work are applied to study the operation and performance of the Wurno Irrigation Scheme, Nigeria, a typical formal medium scale jointly managed irrigation scheme in sub-Saharan Africa. The results of the case study show the performance of the Scheme to be unsatisfactory. This raises questions regarding the views of international lending agencies and governments of developing countries who are looking to smaller, as opposed to large, scale irrigation schemes as the way forward. The study argues that the critical issue is not that of size per se, but the linkages between the primary characteristics of the physical design of the irrigation infrastructure, and the structure of the organizational and institutional arrangements for the operation and management of the scheme.
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Cabral-Dominguez, Carlos Antonio Mayovanex 1963. "Sub-surface drip irrigation uniformity under spatially variable conditions." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/277999.
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Spatial variation of soil moisture content under a sub-surface drip irrigated field was studied. Conventional statistics and geostatistical methods were used to analyze the relation between four soil variables: % sand, % silt, % clay, and soil moisture content. The soil moisture content was measured before, during, and after irrigation using tensiometers. The samples were collected from 63 sites on a 180 by 244 meters (4.45-hectare) cotton field. The pre- and post-irrigation soil moisture content shared the same spatial structure, differing only by the magnitude of their variances. After any irrigation the soil wetter points remained wetter and the drier points remained drier. It was found that the spatial patterns of soil moisture content appear to be stable over time. The ranges obtained from the variograms before and after an irrigation had the same magnitude of influence. The coefficient of uniformity obtained using the gravimetric method was 92.4 %, however, using tensiometers values ranged from 84.4 to 87.3%.
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Huang, Shen S. B. Massachusetts Institute of Technology. "Evaluation of pre-packaged agricultural drip irrigation kits." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/74494.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 67-69).
The purpose of this thesis is to conduct user testing and performance evaluation of two different agricultural pre-packaged drip irrigation kit (PDIK) systems: Chapin Bucket Kit and International Design Enterprises (IDE) drip kit. PDIK systems are a cost-effective type of appropriate technology for the developing world because they reduce agricultural water consumption and can increase crop yield over other methods of irrigation. Overall user testing indicates preference for the IDE drip kit because of ease of installation, low cost, and suitable size for the average household plot. On the other hand, the Chapin Bucket Kit performs better in laboratory evaluation in terms of emitter performance, materials strength, and filter clogging . Ultimately, it is up to users to decide what are the trade-offs that can be made when choosing a PDIK system. This study is conducted under the MIT Development Lab Technology Evaluation and Verification Program (D-lab TEV) and has been financially supported by the MIT Public Service Center and the MIT Department of Foreign Languages and Literature.
by Shen Huang.
S.B.
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Manning, Charles Roger 1956. "Infiltration parameters for mathematical models of furrow irrigation." Thesis, The University of Arizona, 1993. http://hdl.handle.net/10150/278286.
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The effort to improve furrow irrigation design and management by use of mathematical models is hampered by the difficulty of obtaining infiltration parameters that adequately describe the infiltration process in furrows. This difficulty is related to the effect on infiltration of the variability of wetted width of a furrow with depth. Detailed field measurements of twelve furrow irrigations were used to develop infiltration parameters based on three different assumptions regarding the variation of wetted width with depth. These infiltration parameters were used as input into a mathematical model of furrow irrigation, SRFR. Comparison of measured advance times, water surface elevations and volume of water infiltrated with these values computed by SRFR indicates that SRFR gives consistent results based on the input parameters.
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Haq, Zia Ul. "Application of genetic algorithms for irrigation water scheduling." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/72987/.
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A typical irrigation scheduling problem is one of preparing a schedule to service a group of outlets. These outlets may either be serviced sequentially or simultaneously. This problem has an analogy with the classical earliness/tardiness machine scheduling problems in operations research (OR). In previous published work integer programme were used to solve such problems; however, such scheduling problems belong to a class of combinatorial problems known to be computationally demanding (NP-hard). This is widely reported in OR. Hence integer programme can only be used to solve relatively small problems usually in a research environment where considerable computational resources and time can be allocated to solve a single schedule. For practical applications meta-heuristics such as genetic algorithms, simulated annealing or tabu search methods need to be used. However as reported in the literature, these need to be formulated carefully and tested thoroughly. This thesis demonstrates how arranged-demand irrigation scheduling problems can be correctly formulated and solved using genetic algorithms (GA). By interpreting arrangeddemand irrigation scheduling problems as single or multi-machine scheduling problems, the wealth of information accumulated over decades in OR is capitalized on. The objective is to schedule irrigation supplies as close as possible to the requested supply time of the farmers to provide a better level of service. This is in line with the concept of Service Oriented Management (SOM), described as the central goal of irrigation modernization in recent literature. This thesis also emphasizes the importance of rigorous evaluation of heuristics such as GA. First, a series of single machine models is presented that models the warabandi (rotation) type of irrigation distribution systems, where farmers are supplied water sequentially. Next, the multimachine models are presented which model the irrigation water distribution systems where several farmers may be supplied water simultaneously. Two types of multimachine models are defined. The simple multimachine models where all the farmers are supplied with identical discharges and the complex multimachine models where the farmers are allowed to demand different discharges. Two different approaches i.e. the stream tube approach and the time block approach are used to develop the multimachine models. These approaches are evaluated and compared to determine the suitability of either for the irrigation scheduling problems, which is one of the significant contributions of this thesis. The multimachine models are further enhanced by incorporating travel times which is an important part of the surface irrigation canal system and need to be taken into account when determining irrigation schedules. The models presented in this thesis are unique in many aspects. The potential of GA for a wide range of irrigation scheduling problems under arranged demand irrigation system is fully explored through a series of computational experiments.
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Zaccaria, Daniele S. A. "A Methodology to Conduct Diagnostic Performance Assessment and Simulation of Deliveries in Large-Scale Pressurized Irrigation Systems." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/988.
Full textAbstract:
A methodology was developed to conduct diagnostic performance assessment and simulation of alternative delivery scenarios in pressurized irrigation distribution networks. It consists of three components, an agro-hydrologic model able to forecast peak water demand hydrographs, a hydraulic model with capability of simulating the network behavior under different flow configurations, and a set of performance indicators for conducting assessments of performance achievements relative to specified targets.
As a preliminary work, the current delivery schedule of an existing pressurized irrigation network (system 1) and the resulting effects on crop irrigation management were analyzed by simulating soil water balance and irrigation scheduling at field level. Simulations allowed analyzing the on-farm irrigation management under the current rotation deliveries, and comparing it with an alternative flexible irrigation scheduling to maximize crop yields. Results at field level were up-scaled to the entire command area of the system, showing the usefulness of soil water balance and of irrigation scheduling as analytical tools to demonstrate the inconsistency between the current water delivery and crops’ and farmers’ requirements. This preliminary work also allowed highlighting the need for modernizing the irrigation management in the first of the two study areas considered for the present research work (system 1 located in the province of Taranto, southern Italy).
An existing agro-hydrological model conceived to forecast water demand hydrographs in pressurized delivery networks was enhanced through several refinements and amendments of the computation algorithms. The refined model was applied for validation at different management levels on an existing pressurized irrigation system (system 2) located in the province of Foggia, southern Italy, where water withdrawals by farmers and the main hydraulic parameters are recorded on a continuous basis for monitoring purposes.
Results from validation showed that the model is capable of forecasting with good accuracy the timing of peak-demand periods, the seasonal demand irrigation volumes, as well as the hydrographs of hourly flow rates demanded by farmers during these peak periods, especially when it is applied to large multi-cropped command areas.
Performance indicators, originally conceived for diagnostic assessment in canal systems, were modified for application to pressurized distribution networks, and reference standard values were proposed. These indicators were then applied for validation to the second study area (irrigation system 2), where records of water deliveries are available, and showed their usefulness for diagnostic performance assessments.
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Molina, Katerine N. "Seepage Evaluations in Cache Valley Irrigation Canals." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/424.
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Estimation of seepage was done in 39 selected reaches of 11 irrigation canals in the Logan and Blacksmith Fork Irrigation Systems of Cache Valley, Utah. The measurements were performed from June to October, 2008, which includes part of the irrigation season for these canals. The inflow-outflow method was used to measure seepage, in which area and velocities were measured under steady flow conditions. Velocity measurements were done with an acoustic flow meter and the mean velocity was determined using the reduced-point method (velocity measurements at 0.2, 0.6 and or 0.8 of the depth from the water surface).
As a result, reaches with the highest seepage losses were identified. Gaining streams, losing streams, and gaining-losing streams were also identified. Spatial variation was observed along each canal in which a descending trend of the mean seepage loss was found in the downstream direction. Additionally, spatial variation was found between canals, the reaches located in the east part of Logan city presented higher seepage losses than reaches on the west side of the city. Temporal variations were identified by a monthly comparison of seepage losses within reaches which indicated higher seepage losses during late July and August of 2008. Additionally, this report presents comments about the performance of the FlowTracker® ADV® in the present project.
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Siddeek, Fathima Zeena. "Water management for lowland rice irrigation." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/71183.
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A procedure was developed to estimate optimum irrigation requirements for lowland rice cultivation in Southeast Asia. The procedure uses a water balance equation of semi-stochastic nature to maintain minimum desired water depths in paddy fields at the end of each irrigation period. The procedure estimates weekly pan evaporation (EV) and rainfall (RF) at different probability levels, which is then used to determine weekly irrigation requirements at different probability levels.
To illustrate the use of the method, the Kalawewa irrigation scheme in Sri Lanka was selected for demonstration purposes. Different transformations were applied to Rf and EV data in an attempt to normalize these variates and to obtain a unique distribution to describe their variations. Statistical analysis of weekly EV arid RF showed that the power transformation was best able to transform the weekly RF and EV data to normality.
Comparison of the use of the model and current system practices showed that a significant amount of water could be saved even when the system was operated at high probability levels (90% reliability). The irrigation water required when the system was operated at the 72% probability level was about 21% less than the amount required when the system was operated at 90% probability level during some weeks.
The EXTRAN flow routing model was used to simulate water flow in the upper reaches of the main canal system for varying discharges at the head gate each day. The simulated water depths were used to determine the gate settings required at the turnout structures to divert the desired amount of irrigation water into the turnout areas.
The flow simulation for the demonstration area, showed that it was not possible to regulate irrigation water from the main reservoir to meet daily demands at all the turnouts. This was due to the large distances between the regulating reservoir and turnouts that caused appreciable time lag for the flow to reach the turnouts farthest from the regulating reservoir.Ph. D.
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Lindblom, Jenny. "Condensation irrigation : simulations of heat and mass transfer." Licentiate thesis, Luleå : Luleå University of technology, 2006. http://epubl.luth.se/1402-1757/2006/08.
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Ding, Ya. "The choices of irrigation technologies and groundwater conservation in the Kansas High Plains : a dynamic analysis /." Search for this dissertation online, 2005. http://wwwlib.umi.com/cr/ksu/main.
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Doan, David S. B. Massachusetts Institute of Technology. "A cost optimization of solar-powered, drip irrigation systems." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112396.
Full textAbstract:
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 79-81).
This thesis presents a design and cost optimization for solar-powered, drip irrigation systems. Historical irradiance data and crop consumption data are considered and modelled during these design steps. A cost optimization is utilized in order to determine low-cost, optimum configuration that meets the required water consumption rate of a given crop. In this case, Jalgaon, India is used as an example to determine the configuration and cost per acre for solar-powered, drip irrigation systems for sunflowers, tomatoes, and barley. These configurations consisted of five 310 Watt solar panels coupled with a 5m³ water buffer, three 295 Watt solar panels coupled with a 5m³ water buffer, and three 320 Watt solar panels coupled with a 4m³ water buffer, respectively. These systems are projected to cost $4,600, $3,870, and $3,750, respectively. The results of this study show the value of a system optimization of solar-powered, drip irrigation systems.
by David Doan.
S.B.
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Schmoll, Timothy Jon 1942. "Subsurface irrigation of turf: An examination of current methods." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/291901.
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This study examines literature on subsurface irrigation of turf using published and unpublished sources to determine its relevance for the designer of irrigation systems. It looks at two installed sites to determine current industry practices and then develops a model to assist the designer of these systems. Finally areas in need of further research and technical development are suggested. Literature is not readily available to the designer and it is sometimes contradictory. Case studies show that subsurface irrigation is an effective method of irrigating turf, especially in arid parts of the world. A model to select tubing and emitter spacing is developed by summarizing existing literature and case studies. Virtually all areas of design, installation and management need further research. Two primary areas that need further investigation are specific design issues and benefits to the end user such as cost, water savings and maintenance procedures.
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Santos, Francisco Lucio dos Reis Borges Brito dos. "Optimal irrigation system selection: A multiperiod quadratic programming approach." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/184980.
Full textAbstract:
This study reports on the optimal temporal selection of irrigation technologies (graded and level furrows, level basin and drip) that maximize net revenues of a farm unit with different soil types. Unique to this study was the inclusion of irrigation water management strategies that allowed unbiased comparison of the different technologies; for each surface and pressurized system of the study simulation models were used to control the governing parameters that determine the distribution and effectiveness of the applied water, infiltrate equal seasonal water depth in the root zone and adequately irrigate a similar fraction of total cropland area. The ultimate effects on crop yield were assessed by linking the areal water distribution depths with specific crop-water production functions. A generalized mean variance model was constructed to simulate the selected production activities of the farm; to integrate the water delivery irrigation systems, crop mix and soil endowments, and to include the alternative irrigation water application strategies. Adjustments to stochastic water supplies and revenues were also included into the model as well as regulatory constraints associated with the quantity of water allocated over the growing season and risk preference levels. Given the model assumptions, the results indicate that: (1) the generalized mean variance model was successful in establishing an intertemporal path for irrigation systems adoption; (2) high uniformity level basins were the technology of choice in all soils, substituting the low uniformity graded furrows; (3) with yield increases realized, drip systems are likely to be first adopted in soils of high intake rates; (4) increasing levels of risk aversion changed the area-technology mix and added to reductions in the areas under production; area reductions under level basin took place in high intake soils, suggesting that adoption of level basin in low intake rate soils provide higher level of farm security and are more likely to be given priority in the farm enterprise planning by growers defined by the model as risk averse; (5) the farm structure is considerably dependent upon cotton for the production of net revenue; wheat contributions to net revenue were relatively small due to the economic inability of the crop to command scarce resources and generate profits.
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Thompson, Evan J. "Hydraulics of IDEal Drip Irrigation Systems." DigitalCommons@USU, 2009. https://digitalcommons.usu.edu/etd/296.
Full textAbstract:
The hydraulics of IDEal drip irrigation system components were analyzed under controlled laboratory conditions and the results can be applied to the design of IDEal systems. The hydraulic loss coefficient for the lateral-submain connector valves was determined based on laboratory measurements. It was found that the hydraulic loss due to friction in the lay-flat laterals can be accurately estimated with standard friction loss equations using a smaller effective diameter based on the wall thickness and inlet pressure head. The equivalent length barb loss, expressed as an equivalent length of lateral, was calculated for button emitters, as well as for micro-tubes inserted to lengths of 5 and 10 cm. It was concluded that the barb loss is essentially constant over the micro-tube insertion range of 5-10 cm. The head-discharge relationship and coefficient of manufacturer's variation of pre-punched lateral holes (without emitters), button emitters, and micro-tubes were characterized.
Finally, several IDEal drip irrigation systems in the Central Rift Valley of Ethiopia were evaluated in the field. Recommendations were given for future research and improvements in the manufacturing, installation, operation, and maintenance of IDEal drip irrigation equipment.
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Taylor, Katherine Anne. "Reducing the power required for irrigation : designing low-pressure, pressure-compensating drip irrigation emitters and high efficiency solar-powered pumps for emerging markets." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/100350.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 81-86).
This thesis presents a mathematical model investigating the physics behind pressure compensating (PC) drip irrigation emitters and a design of a highly efficient solar powered centrifugal pump for small-acreage farmers drawing from shallow groundwater. The global community is facing a worsening crisis with regards to the water-energy agriculture nexus. Irrigation is a proven way to increase the agricultural productivity of a plot of land; however, with a growing population, it will be necessary to invest in methods of irrigation that are both energy- and water-efficient, and intensify the agricultural output per unit of land. Drip irrigation, a method of irrigation where water is delivered directly to the plant roots through a network of tubes and valves, is a highly water-efficient method that gives high yield per unit area. The current challenge to adoption facing drip irrigation is the high capital and operating costs. It is possible to cut these costs by developing a valve, called an emitter, that gives the desired flow rate at a lower pressure. This lower pressure in turn requires less energy from the pump, allowing for a smaller and less expensive pump, and even making a solar-powered system affordable for small-acreage farmers. In coming decades, it will become increasingly necessary to switch from fossil-fuel based energy to renewables, such as solar. For small acreage farmers in the developing world, this switch will not only alleviate the pains of paying the recurring and volatile costs for diesel fuel, it will also help to lighten the load on the electrical grid by those using electric pumps.
by Katherine Anne Taylor.
S.M.
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Silva, Euzebio Medrado da. "Analysis of furrow irrigation uniformity as affected by furrow spacing." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185190.
Full textAbstract:
This research examines the effects of furrow spacing on irrigation uniformity and efficiency. Laboratory and field experiments were conducted to obtain information on soil physical characteristics, furrow infiltration and water advance data in order to validate the theoretical results. A furrow infiltration model based on Richards' equation and a finite element technique is developed and used to predict infiltrated depths in the transverse and longitudinal directions relative to the furrow centerline and furrow inlet, respectively. The model predicted measured furrow infiltration in the field from the third irrigation but failed to do so for the first and second irrigations. Simulations of furrow irrigation in a hypothetical soil with various furrow spacings showed that cumulative infiltration is not affected by furrow spacing until the lateral wetting front reaches the imaginary vertical boundary located midway between two furrows. An analysis of uniformity and efficiency from predicted water distribution profiles from field irrigated furrows are conclusive in that the use of longitudinal water distribution profile alone is not enough to assess the performance of furrow irrigation. The transverse distribution of infiltrated depths which is a function of furrow spacing must be included in the analysis.
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Copeland, Russell Dean 1963. "Hydraulic, water and energy use evaluation of subsurface trickle irrigation system." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/278073.
Full textAbstract:
The hydraulics, water use, and energy use of a two year old subsurface drip irrigation system installed at the Maricopa Agricultural Center in southern Arizona were examined to evaluate the performance of typical subsurface drip irrigation systems. Although the pressure distribution was better than expected due to the effect of the looped network, the average discharge rate of the drip tape decreased by 20% as reflected by the change in the discharge coefficient from 0.45 to 0.36 over two years and emitter plugging resulted in the statistical uniformity being only 64.6%. Water use was higher than expected at 50.76 and 41 inches during the two years of use. The total annual energy requirements for the system including direct, 7593 megajoules/hectare/year, and indirect, 12965 megajoules/hectare/year, inputs was 24318 megajoules/hectare/year.
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Hermansson, Hanna, and Louise Lundblad. "Automatic irrigation system for plants." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264445.
Full textAbstract:
The purpose of this project was to develop an automatic irrigation system for plants. It is beneficial to have plants indoors. In addition to their air-purifying qualities, they have been proven to increase the productivity of employees at workplaces, as well as decrease the amount of sick leave. Three research question were investigated: how much energy the system requires and if it is possible to replace the energy source with an alternative energy source, how well the system stabilises and how a wireless regulation can be implemented. The final design consisted of a mictrocontroller which controlled the system, a water pump, a moisture level sensor and a plant on which everything was tested. The system was left during a four week period to see how well it managed. The project resulted in a system that managed to keep the plant alive. The energy demand of the system could be covered by solar cells instead of batteries.Syftet med detta projekt var att utveckla ett automatiskt bevattningssystem för växter. Det är fördelaktigt att ha växter inomhus. Bland annat har det bevisats att växter i kontorslandskap ökar produktiviteten hos de personer som arbetar där, samt att antalet uttagna sjukdagar minskar. Fortsättningsvis var det tre stycken forskningsfrågor som undersöktes, hur mycket energi kräver systemet och är det möjligt att ersätta energikällan med en alternativ energikälla, hur väl stabiliserar sig systemet samt hur kan en trådlös reglering implementeras. Den slutliga designen bestod av en mikrokontroller som styrde systemet, en vattenpump, en fuktighetssensor och en planta på vilken testerna utfördes. Systemet lämnades i fyra veckor för att se hur väl det klarade sin uppgift. Resultatet blev att växten överlevde vilket innebär att systemet fungerade. Möjligheten att byta ut batterierna mor solceller studerades och slutsatsen är att detta byte är möjligt.
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Eftekharzadeh, Shahriar. "Canal side weirs for water delivery to irrigation furrows." Thesis, The University of Arizona, 1985. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1985_139_sip1_w.pdf&type=application/pdf.
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Elawad, Omer Mohamed Ahmed. "Multicriterion approach to the evaluation of irrigation systems performance." Thesis, University of Newcastle Upon Tyne, 1991. http://hdl.handle.net/10443/187.
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In recent years the importance and the lack of comprehensive methodologies for measuring the performance of existing irrigation schemes has been widely expressed. The objective of this study is to develop a systematic procedure by which some use can be made of the large quantities of data, already routinely collected in irrigation schemes, for the purpose of their regular seasonal evaluation. Consideration is confined to the performance of the main irrigation system of small-holder, canal-fed irrigation schemes of the developing countries. A generalized conceptual framework has been developed for a methodology by which the performance criteria for any irrigation system can be identified and combined together into a single index which measures the overall performance of the system. Six criteria have been identified as adequate for characterizing the important features of the performance of any irrigation system. These are; adequacy, equity, water losses, water user convenience, cost and durability. New methods for characterizing each of adequacy, equity and water user convenience have been developed and tested using data from the Gezira scheme, Sudan. Characterization of adequacy, equity and water losses involves the development of a soil moisture simulation model and characterization of the water user convenience involves the use of the concept of the fuzzy set theory. Identification of the criteria to be used in evaluating any particular system(s) and evaluating the trade-offs between them requires the participation of the decision-maker in the system(s) to be evaluated. This is achieved through the use of the multi-attribute utility theory. It has been applied with a group of Sudanese officials in order to derive their utility functions. The utility function reflects the decision-maker's strength of preferences over different achievement levels of each objective and his trade-offs between different objectives. The derived utility functions are reported and their usefulness is discussed. The methodology developed provides a useful tool for measuring the performance of irrigation systems, comparing the performance of different systems and assessing improvement in performance resulting from rehabilitation investments.
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Papadopoulos, Aristotelis. "Mathematical model for border irrigation of cracked clay soils." Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305585.
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Al-Shatti, Ismail K. "Industrial wastewater as a resource for irrigation in Kuwait." Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.255975.
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Hassanli, A. M. "Modelling and optimisation of pressure irrigation systems /." Title page, abstract and contents only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phh353.pdf.
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Haberland, Julio Andres. "AgIIS, Agricultural Irrigation Imaging System, design and application." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/279836.
Full textAbstract:
Remote sensing is a tool that is increasingly used in agriculture for crop management purposes. A ground-based remote sensing data acquisition system was designed, constructed, and implemented to collect high spatial and temporal resolution data in irrigated agriculture. The system was composed of a rail that mounts on a linear move irrigation machine, and a small cart that runs back and forth on the rail. The cart was equipped with a sensors package that measured reflectance in four discrete wavelengths (550 nm, 660 nm, 720 nm, and 810 nm, all 10 nm bandwidth) and an infrared thermometer. A global positioning system and triggers on the rail indicated cart position. The data was postprocessed in order to generate vegetation maps, N and water status maps and other indices relevant for site-specific crop management. A geographic information system (GIS) was used to generate images of the field on any desired day. The system was named AgIIS (A̲gricultural I̲rrigation I̲maging S̲ystem). This ground based remote sensing acquisition system was developed at the Agricultural and Biosystems Engineering Department at the University of Arizona in conjunction with the U.S. Water Conservation Laboratory in Phoenix, as part of a cooperative study primarily funded by the Idaho National Environmental and Engineering Laboratory. A second phase of the study utilized data acquired with AgIIS during the 1999 cotton growing season to model petiole nitrate (PNO₃⁻) and total leaf N. A latin square experimental design with optimal and low water and optimal and low N was used to evaluate N status under water and no water stress conditions. Multivariable models were generated with neural networks (NN) and multilinear regression (MLR). Single variable models were generated from chlorophyll meter readings (SPAD) and from the Canopy Chlorophyll Content Index (CCCI). All models were evaluated against observed PNO₃⁻ and total leaf N levels. The NN models showed the highest correlation with PNO₃⁻ and total leaf N. AgIIS was a reliable and efficient data acquisition system for research and also showed potential for use in commercial farming systems.
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Finley, Sara. "Reuse of domestic greywater for the irrigation of food crops." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32610.
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As global water resources decline, reuse of domestic greywater for the irrigation of home gardens is quickly becoming widespread in many parts of the world. However, the sanitary implications of reusing greywater to water edible crops remain uncertain. This study examined the benefits and risks associated with domestic greywater reuse for the purposes of vegetable garden irrigation. Untreated (settled only) and treated (settling and slow sand filtration) greywater collected from a family home was analyzed for basic water quality parameters, over a period of eight weeks. During that time, both greywaters were used to irrigate individually potted plots of lettuce, carrots and peppers in a greenhouse. Tap water was used as control. Upon maturity, plants were harvested and the edible portions tested for fecal coliforms and fecal streptococci, common indicators for the presence of pathogenic microorganisms. Heavy metals were not detected in the greywater, but both fecal coliforms and fecal streptococci were present in high levels, averaging 4 x 105/100mL and 2 x 103/100mL of greywater, respectively. Despite these high counts, no significant difference in contamination levels was observed between crops irrigated with tap water, untreated and treated greywaters. Fecal coliform levels were highest in carrots and fecal streptococcus levels highest on lettuce leaves. However, contamination levels for all crops were low and do not represent a significant health risk. Plant growth and productivity were unaffected by the water quality, owing to the low N, P and K levels of the greywater. These results reinforce the potential of domestic greywater as an alternative irrigation sourceDans le contexte d'un déclin et d'une perte de fiabilité des ressources hydriques du globe, la réutilisation des eaux grises (eaux le lavage) domestiques pour les fins d'irrigation devient une option populaire pour les ménages un peu partout dans le monde. Pourtant, les implications sanitaires d'une telle pratique pour l'irrigation des plantes comestibles ne sont pas encore bien comprises. Cette étude vise à examiner les bénéfices et risques associés à la réutilisation des eaux grises pour arroser les jardins potagers domestiques. Il met son focus sur la possibilité de contamination des légumes par des organismes pathogéniques et les métaux lourdes qui peuvent être présents dans les refuts domestiques. Les eaux grises d'une famille montréalaise ont été collectionnés et analysés pour des paramètres de base, y inclut les pathogènes et les métaux lourds, sur une période de 8 semaines. Pendant ce temps, ces eaux grises ont été utilisés à irriguer des plantations individuels de laitues, carottes, et poivrons rouges dans une serre de recherche. L'eau du robinet a servi comme contrôle. À la maturité, les plantes ont étés cueillis et les portions comestibles testés pour la présence des coliformes et des streptocoques fécaux, deux bactéries normalement utilisés pour indiquer la présence d'organismes pathogéniques. Puisque les métaux lourds n'étaient pas présents dans les eaux grises, ils n'ont pas étés testés dans les légumes. Les résultats ont indiqué un niveau élevé de bactéries indicateurs dans les eaux grises, mais la différence de contamination entre les légumes irrigués avec les eaux de robinet et ceux irrigués ave
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Johnson, Eric (Eric M. ). "Self-installation of drip irrigation emitters for prototype emitter testing." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105700.
Full textAbstract:
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (page 31).
In this thesis, I tested methods of adhering factory-made drip emitters to the interior of short segments of piping. Different types of adhesive and pipe material combinations were tested, and I selected three combinations for further testing. Performance similar to factory-installed drip emitters was achieved at low pressure, but the necessary watertight seals repeatedly burst at higher water pressures. Alterations to the drip emitter and installation procedure are recommended to increase reliability and resilience of the installation.
by Eric Johnson.
S.B.
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Narain, Jaya S. M. Massachusetts Institute of Technology. "A hybrid computational and analytical model of irrigation drip emitters." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111708.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 63-65).
This thesis details a hybrid computational and analytical model to predict the performance of inline pressure-compensating (PC) drip emitters. A verified CFD model is used to predict flow behavior through tortuous paths. A method of extracting a pressure scaling parameter from the CFD results for use in an analytical model is presented. Analytical expressions that describe the bending of asymmetric rectangular membranes in inline drip emitters are detailed. These expressions are combined with finite element analysis (FEA) describing the shearing behavior of the membrane to model the total flow resistance through the emitter. Analytical expressions that describe the fluid mechanics of duct and turbulent flows are used to predict the net flow rate out of the emitter. The final model is verified for three distinct emitter geometries. The hybrid model presented in this paper has wide applicability - it can be applied to asymmetrical emitter geometries that have tortuous paths and other complex flow geometries. The hybrid model benefits from the accuracy of computational modeling for complex flows and contact interactions, and the processing speed of analytical models. Because of its accuracy and speed, the model can be used reliably as a design tool for inline PC emitters.
by Jaya Narain.
S.M.
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Ngimbwa, Peter Cosmas. "An Irrigation Decision Support Tool (IDST) for Smallholdings in Tanzania." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461171005.
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Ahdab, Yvana D. (Yvana Damiella). "Performance and economics of monovalent selective electrodialysis desalination for irrigation." Thesis, Massachusetts Institute of Technology, 2021. https://hdl.handle.net/1721.1/130834.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, February, 2021Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 261-276).
Reverse osmosis (RO) is the most widely used desalination technology for the treatment of irrigation source water and wastewater. Brackish groundwater, seawater, and agricultural effluent often contain both monovalent ions damaging to crops (Na⁺, Cl⁻) and divalent ions beneficial for crops (Ca²⁺, Mg²⁺, SO²⁻₄). RO removes both types of ions. These beneficial ions must then be reintroduced to the desalinated water through the addition of fertilizer. Monovalent selective electrodialysis (MSED) demonstrates greater potential to align with the needs of the agriculture sector. MSED is a variant of conventional electrodialysis (ED). MSED preferentially removes monovalent ions relative to multi-valent ions, defined as monovalent selectivity, via selective ion-exchange membranes. MSED operates at a significantly higher water recovery than RO.
In the treatment of irrigation source water, MSED's selective removal may reduce fertilizer requirements and associated costs, while its greater recovery saves water and decreases the volume of brine for disposal. In the treatment of agricultural wastewater, MSED's selective removal of sodium, the biggest barrier to water reuse, may help greenhouses achieve minimal liquid discharge. Despite the possible economic and environmental benefits of MSED, the technology has not been commercially employed for the treatment of agricultural water. Rather, it has historically been used to concentrate sodium chloride from seawater brine for salt production. Consequently, the literature has focused on characterizing and designing MSED systems almost exclusively for high salinity applications. Because water composition greatly influences membrane behavior, separate analyses must be conducted to determine how MSED will perform for lower salinity applications relevant to agriculture.
This thesis investigates the membrane performance, energetics, and economics of MSED for the treatment of irrigation source water and wastewater. Experiments are conducted on two types of MSED membranes, one of which has never been tested in the literature, to characterize the following system parameters as a function of feedwater composition: monovalent selectivity, ion transport, membrane resistance, membrane permeability, and limiting current density. Feedwaters used in the present MSED experiments simulate seawater and numerous compositions of brackish groundwater and agricultural effluent, which often vary with location. We find that both MSED membranes demonstrate notable monovalent selectivity for all tested feedwaters, although the selectivity varies with ionic composition and salinity. The experimentally-determined system parameters then serve as inputs to our MSED cost model.
This model evaluates fertilizer and water savings as a function of farm size for the different feedwaters and membranes. These savings are weighed against the greater capital and operating costs of MSED relative to RO, in order determine the feasibility of MSED adoption for irrigation. While the energy consumption of MSED is comparable to that of RO for the treatment of brackish water and wastewater, MSED requires significantly more energy to desalinate seawater. Solar powered, in addition to conventionally powered, desalination is integrated into the cost model for seawater. The insights described in this thesis suggest that MSED may be the future of desalination for agriculture, particularly for brackish water and wastewater treatment.
by Yvana D. Ahdab.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Harper, Samantha (Samantha E. ). "Real-time control of soil moisture for efficient irrigation." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111509.
Full textAbstract:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2017.Cataloged from PDF version of thesis. Page 52 blank.
Includes bibliographical references (pages 31-34).
In the field of precision irrigation control, two classes of controllers have emerged - classical controllers and model based controllers. The most widely-used real-time closed-loop controller is a bang-bang controller that applies water at a predetermined rate, duration, and minimum soil moisture. Due to the ease of installation of soil moisture sensors, this technology has been installed around the world. There have been few studies on altering the controller used with this existing infrastructure. This thesis articulates a model for using a real-time proportional-integral-derivative (PID) controller to minimize water use using HYDRUS- 1D, a software package for simulating the one-dimensional movement of water, heat, and solutes in porous media, to simulate soil moisture. In a direct comparison between the two controllers, the PID controller uses less water. However, small violations of the target soil moisture and optimization of the PID parameters present the current barrier to implementation of this technology. Maintaining soil moisture at or above minimal depletion is critical to support crop health throughout a growing season. PID controllers offer a mid-point between the simplistic bang-bang controllers and the model based controllers that require large datasets, wireless network infrastructure, and robust computing systems. With proper calibration, PID controllers can be implemented in the field with the same sensors that are widely used with bang-bang controllers resulting in a reduction of water use in regions where water is scarce.
by Samantha Harper.
M. Eng.
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Abdulhussain, Mohamed Fidahussain 1964. "Gravity bubbler irrigation systems on steep slopes converted to bench terraces." Thesis, The University of Arizona, 1994. http://hdl.handle.net/10150/278410.
Full textAbstract:
Gravity bubbler irrigation is a new mode of irrigation activated by the existing pressure in conventional irrigation supply channels. In gravity flow systems on steep slopes, pressure increases in the downstream sections of the pipe and must be dissipated for uniform application. A design procedure for gravity bubbler irrigation systems on inclined steep slopes or converted to bench terrace systems is described in detail. The design is based on the use of orifices as energy dissipating devices. Laboratory tests were conducted to determine graphical relationships and coefficients for estimating the head loss for an orifice made from PVC. The head loss coefficient is a function of the orifice to pipe diameter ratio and can be expressed by an equation of the form Ko = abetab where a and b are constants determined from test data and beta is the ratio of diameters. A prototype gravity bubbler irrigation system was designed and installed.
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Suarez-Rey, Elisa Maria. "Subsurface drip irrigation of bermudagrass turf in Arizona: Benefits and limitations." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/280210.
Full textAbstract:
Subsurface drip irrigation was compared to sprinkler irrigation on bermudagrass turf during three consecutive years using tertiary treated wastewater. Irrigation amount required by each treatment, visual appearance of the grass, shoot biomass production, and soil salinity were measured, and potential management problems were identified. The amount of irrigation water applied via subsurface irrigation was similar or higher than that applied via sprinkler irrigation for a turf of similar quality. Shoot biomass production did not differ between both irrigation methods when similar amounts of water were applied. Soil salinity, measured as electrical conductivity, was monitored at the beginning and end of each season. The changes in electrical conductivity at the end of every irrigation season did not negatively affect the appearance of the turf in any of the years. Emitter clogging by root intrusion was identified as a potential problem in the subsurface drip irrigation system. A series of greenhouse experiments were conducted to evaluate the effect of different herbicides and acids at several concentrations on root intrusion into subsurface drip emitters. The first greenhouse experiment was a study intended to identify chemical concentrations that could inhibit bermudagrass root growth in soil without negatively affecting the visual appearance of the grass. As a result, two herbicides, trifluralin and thiazopyr, and one acid, phosphoric acid, were selected for a second greenhouse experiment. The second greenhouse experiment focused on the effects of the two herbicides and the acid on root intrusion into subsurface drip emitters. Only the emitters treated with thiazopyr at the highest dose were completely clean, root-free emitters.
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Wodrich, Timothy Dirk 1962. "A device for controlling the installation rate of subsurface trickle irrigation laterals." Thesis, The University of Arizona, 1990. http://hdl.handle.net/10150/278693.
Full textAbstract:
A three-point hitch, mounted implement was developed to control the injection rate of trickle irrigation tubing. Power to the implement was supplied by the tractor's electric and hydraulic systems. A doppler radar velocity sensor measured ground speed and provided a signal to a single board computer. The computer generated an output signal which operated a throttling valve that controlled the hydraulic flow to the motor coupled to one of two pulling wheels. The wheels, mounted on parallel shafts with their faces in contact, utilized friction to feed the tubing. An error feedback loop controlled the pulling wheels speed with satisfactory operation being obtained over a range of travel speeds of 3.7 km/h to 5.6 km/h. Extra tube dispensing and cutting systems were incorporated in the design. These were manually activated by the operator when required.
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Nabulsi, Y. A. "Control of the irrigation water resources of the Al-Hasa oasis." Thesis, Liverpool John Moores University, 1987. http://researchonline.ljmu.ac.uk/5592/.
Full textAbstract:
This thesis describes the present situation of the Al-Hasa oasis, which is critically dependent on a single over-used water resource. Evidence is presented to show that water usage is inefficient, and that real improvements are possible, but only if the local farmers are provided with the means of determining the soil moisture levels of their fields. Simple tensiometers and soil moisture cells are considered for this purpose and both would be effective. Soil moisture cells are likely to be the better choice, but more work is needed to evaluate their response to saline soil moisture conditions. The thesis shows that the widely used pressure plate (for laboratory evaluations) is less accurate than is the simpler filter paper system. Such laboratory determinations will be needed to ensure that the chosen field instruments are as accurate as is wanted. An interesting, and still incompletely understood, phenomenon is that the soil grain sizes do affect the accuracy of results from the chosen field instruments. More work is planned on this subject. A crucial factor also affecting the long term security of the oasis is to improve near surface drainage and evidence is presented that details the adverse effects of the present inadequate drainage system. In view of the vast financial investment already made into the drainage of the oasis, improvements that allow a better drainage of each individual field are seen as sensible. Evaluations of more modern soil moisture measuring equipment (transducer and psychrometer systems) reveal that these are inappropriate for use at Al-Hasa. The emphasis of the thesis is on the positive contribution to water use efficiency that can be achieved by the individual farmer. If the thesis conclusions are accepted then the continued prosperity of Al-Hasa can be assured at a very small cost.
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Abdulkadir, Ahmadu. "Land evaluation for smallholder irrigation in Bauchi State, Northern Nigeria." Thesis, University of East Anglia, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372209.
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Malik, Manzoor Ahmad. "Evaluation of infiltration into freshly tilled soils under sprinkler irrigation." Thesis, University of Newcastle Upon Tyne, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283905.
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