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Gemesi, Zsolt. "Plumbing agricultural landscapes for water quality improvement coexistence of intensive agriculture and good water quality /". [Ames, Iowa : Iowa State University], 2007.
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Thiouf, Alassane 1959. "Water management for agriculture in Senegal". Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/191941.
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Water problems in the Sahel region have lead to a study of water management in one country of the area, Senegal. Farming systems, human resources, and livestock production of the country have been analysed. Natural resources, water, soil, topography, and vegetation have also been studied. The study of the different resource shows the potential of improvement in water management. A specific location in Senegal, Kedougou, is chosen and a water management pilot project is designed. The Gambia river and rainfall are the main sources of water for the project. The project is used for different purposes among which are agricultural production, research, and economic improvement. The project is suitable technically, and social, political and economic environments are favorable. The pilot project demonstrates the adequacy of the technologies used for the project. A preliminary estimation of the costs gives an acceptable financial input for such a system.
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Simas, Maria Joao Correia de 1966. "Soil water determination by natural gamma radiation attenuation". Thesis, The University of Arizona, 1993. http://hdl.handle.net/10150/278348.
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The purpose of the study was to determine the soil moisture content by measuring the naturally occurring gamma radiation in the soil. A calibration procedure was developed both in laboratory and in the field. In the laboratory, two different sample sizes were used: three-inch diameter, and 18-inch diameter columns, both 15 cm long. Small size soil samples (three-inch diameter) cannot be used to predict the calibration curve in the field, whereas the larger soil samples (18-inch diameter) calibration may be used to predict the field calibration curve. The prediction limits for the calibration curve done in the field are of ±5%, which is an unacceptable level of precision. It was also observed that the distance between the detector and the soil should always be kept constant, and that the top 15 cm of the soil contribute to approximately 95% of the radiation measured at the soil surface.
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Smith, S. Andrew Enticknap. "Water first". Connect to full text, 2002. http://thesis.anu.edu.au/public/adt-ANU20050314.135921/index.html.
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Dale, Don. "Saving City Water". College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/295530.
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Ketchum, Lynn. "Backyard Water Management". College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/295532.
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Kingdon, Lorraine B. "Hot Water Issues". College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/295533.
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Kingdon, Lorraine B. "Water Quality Watchdogs". College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/295555.
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McCormick, Suzanne. "Air and Water Quality". College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/295707.
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Oliveira, Aureo Silva 1965. "Determination of head lettuce crop coefficient and water use in central Arizona". Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/282779.
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The assessment of crop evapotranspiration (ET) has received intensive research due to its critical role in irrigation management and water conservation studies. Because weather conditions largely determine ET, various methods based on meteorological factors have been developed to estimate ET rates. In order to accommodate the concept of reference crop ET (ETo), evaluation of weather data quality has been addressed. In this research, 9 year (1989-1997) weather data from the AZMET weather station at the Maricopa Agricultural Center were used to compare daily and 10 day average ETo estimated by the Hargreaves (HARG), FAO 24 Penman (FAOP), and FAO Penman-Monteith (FAOPM) methods. Before ET calculation, the weather data were evaluated for the influence of aridity at the weather station site and sensor calibration/malfunctioning problems. Corrections were made on temperature and solar radiation data. Reference ET as reported by the AZMET was also considered for comparison purposes. In general, the weather data correction decreased ETo estimates 18.3%, on average. The highest reduction (23.5%) was obtained with the FAOPM method. When this method was used as the standard for ETo estimate comparison, the FAOP method corrected for site aridity ranked first as predictor of ETo despite its tendency for overestimation. At the Maricopa Agricultural Center, a two year field research (Fall-Winter of 1996/97 and 1997/98) was carried out to derive head lettuce (Lactuca sativa L.) crop coefficient (Kc) and to investigate the effects of ETo method in the shape and values of the crop coefficient curve. For the periods of low crop ET, the 2 year (Kc) from the HARG, FAOP, and FAOPM methods did not differ significantly. However, in the peak demand period, crop coefficients derived from the three methods peaked at different values. The predicted peak (Kc) was 0.87, 0.72, and 0.82 for the HARG, FAOP, and FAOPM methods, respectively. These results reflect the tendency of ETo underestimation by the HARG method and overestimation by the FAOP method under and conditions. Crop coefficients derived in the 96/97 growing season were then used to investigate the effects of (Kc) and ETo mismatching in the water use and yield of lettuce during the 97/98 growing season. To reach such objectives, an experiment design in Latin square with four replications and four treatments was carried out. Differences in seasonal water depth were as high as 33 mm among treatments. The analysis of variance revealed that the treatments did not induce lettuce marketable yield statistically different at the 5% significance level.
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Aboeltiyah, Alzway Aiad A. Akhreim. "Water quality problems in irrigated agriculture in Libya". Thesis, University of Glasgow, 2015. http://theses.gla.ac.uk/7091/.
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The Kufra region of south eastern Libya comprises an area about 850 km south to north, and some 500 km wide rising to 450 m above sea level. Rainfall is low and agriculture depends on irrigation. Most of the population of Kufra are private farmers who use flood irrigation from shallow wells (19-60 m), but there are co-operatives of farmers that have shared the cost of deeper wells (120 - 150 m) and sprinkler irrigation. The Kufra Agricultural Project (KAP) state farm is made up of 100 circles (farms) each having its own deep well (220 – 352 m) and rotary sprinkler. The experimental work was conducted in three phases. An initial study was made of soil profiles and irrigation water on 4 private and 4 state farms. An inter laboratory study compared results in the KAP and Glasgow University (GU) laboratories. The third phase was a survey of top soils, irrigation water, crop yield and questionnaires for a much larger number of farms. Chapter 3 describes the comparison between chemical analysis results of 33 soils in the KAP and GU laboratories. There was a good level of agreement between the two laboratories. The high correlation coefficients indicate a high level of precision in both laboratories. However there were systematic differences between the two laboratories, results for EC, Ca2+, Mg2+ and Cl- were 2% to 6% lower in the KAP laboratory. There were no significant differences in the results for Na+ and K+ between the laboratories. It is important that all analyses were carried out in one laboratory, so all subsequent samples were sent to the KAP laboratory. Chapter 4 evaluates the quality of irrigation water from 86 wells in the Kufra region in line with FAO and USDA standards for irrigated agriculture. pH, EC, Ca2+, Mg2+, Na+ and SAR were not significantly affected in state farms by well depth or age, but were significantly affected in the private farms by well depth, where the values were higher in shallow wells and significantly related to well age. There are two responses to well age related to well depth shown by two distinct lines. The shallow wells (<30 m) show a significant (p< 0.001) increase in EC, Ca2+ and Na+ and significant (p< 0.01) increase in Mg2+ as well age decreases. The deeper wells (>30 m) exhibits no significant effect of well age (p> 0.05). USDA classification indicates that the water of all the wells of private farms is unsuitable for irrigation purposes. The FAO criteria showed that all private wells had limitations on use due to salinity and SAR. (EC: 78% severe, 22% slight/moderate ; SAR: 35% severe, 65% slight/moderate) Chapter 5 describes a survey of soil profiles from state and private farms. Irrigation lowered the salinity of the virgin soil profiles, with a clear distinction observed between the virgin and irrigated profiles for EC and water soluble Ca2+, Mg2+, Na+, K+, Cl- and SO42- in state farms, and for EC and water soluble Na+, Cl- and SO42- in private farms. In the virgin soil profiles, these parameters showed a clear decrease with depth, while in the irrigated soil profiles they were much lower in concentration and more uniform with depth. There was no clear trend with depth in irrigated soil profiles for pH, HCO3-, CaCO3%, exchangeable cations, and ESP % in the state farms and for pH, water soluble Ca2+, Mg2+and K+, CaCO3%, exchangeable cations, and ESP% in the private farms. The profile averages for pH, EC, ESP%, water soluble Na+, Cl-, HCO3- and SO42- and exchangeable sodium were significantly greater (t-test, p≤0.05) in the irrigated profiles of private farms than in KAP farms. The irrigated topsoils (0–25 cm) showed similar results except that bicarbonate and sulphate were not significantly different. The second part of chapter 5 describes a larger survey of irrigated topsoils. This showed that the pH, EC, ESP% and exchangeable Na+ were much higher in the private farms compared to state farms soils. According to the USDA classification all state farm soils were classed as normal, while 70% of private farm soils were classed as saline alkaline, 15% normal, 10% saline and 5% alkaline. There was no significant effect of crop type on any soil parameter for state or private farms. There was no significant correlation in the combined data for state and private farms between irrigation water and soil for pH, Ca2+ and Mg2+ but there is for EC, Na+ and SAR. In all the graphs there are 2 clusters of points separating the state and private farms which masks the correlation relationship. Chapter 6 compares the yields of alfalfa and potatoes in the state and private farms. The mean values for dry yield of alfalfa from state (6.32 t/ha) and private (3.06 t/ha) farms were significantly different (p<0.001, pooled t-test). The age of the alfalfa crop had a significant (p<0.001) positive effect on yield in the state farms, but a significant (p<0.001) negative effect in private farms. Crops on the private farms were 2 to 8 years old compared with under 2 years on the state farms. Although there were low yields at high values of water and soil parameters (private farms) and high yields at low values of water and soil parameters (state farms) plotting yield against these parameters shows 2 clusters. Looking at the private farms alone there was no significant correlation between alfalfa yield and any of the quality parameters for soil or water. No potatoes were grown on state farms when the samples were collected, so historical data was used (average yield 40 t/ha). The mean yield of potatoes from private farms was significantly lower (p<0.001) 23.16 t/ha. None of the correlation relationships between crop yield with soil and water quality parameters for private farms was significant. Despite the large differences in soil and irrigation water chemistry between state and private farms, there was no evidence that poor irrigation water quality or soil salinity currently limits production on private farms. Chapter 7 describes the survey of private farmers and shows that 81% of respondents did not consider farming as a professional activity they could rely on, but rather an activity to fill their free time. The study also examined other aspects including the farmers’ education level, the farms’ age, irrigation and the impact of water salinity, types and sources of fertilisers. The study concluded that traditional agricultural systems in this region are not built on a scientific basis, or an adequate knowledge of economic feasibility. Consequently, the production rates of agricultural crops are very low.
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Kingdon, Lorraine B. "Double Duty for Irrigation Water". College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/295634.
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McCoy, Jan. "Treating Waste Water With Weeds". College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/295662.
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Törnqvist, Rebecka. "Basin-scale change in water availability and water quality under intensified irrigated agriculture". Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-93214.
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Changes in land use and water use can greatly impact the cycling of water and water-borne substances. Increased redistribution of river water to irrigated fields can cause enhanced evapotranspiration and decreased river discharge. Additionally, the water quality can be affected by the external input of fertilisers and pesticides, and by changed pollutant transport pathways in expansive irrigation canal systems. This thesis examines basin-scale changes in water use, river discharge, water quality and nitrogen (N) loading under conditions of intensified irrigated agriculture, using the Aral Sea drainage basin (ASDB) with its two large rivers Syr Darya and Amu Darya in Central Asia as study area. Results show that more efficient irrigation techniques could reduce outtake of river water to the cotton fields in the ASDB by about 10 km3/year, while the corresponding river water saving at the outlet would be 60% lower. The result illustrates the importance of accounting for return flows of irrigation water in basin-scale water saving assessments. Moreover, a decrease in riverine N concentrations at the outlet of the Amu Darya River Basin (ADRB) was observed during a 40-year period of increasing N fertiliser input. The decrease was identified to be primarily caused by increased recirculation of river water in the irrigation system, leading to increased flow-path lengths and enhanced N attenuation. Decreasing N loads were shown to be primarily related to reduced discharge. N export from the basin may further decrease due to projected discharge reductions related to climate change. Furthermore, nutrients and metals were occasionally found at concentrations above drinking water guideline values in surface waters in the ADRB. However, metal concentrations in groundwater in the lower ADRB were subject to orders of magnitude higher health hazards. Projected decrease in downstream surface water availability would thus imply decreased access to water suitable for drinking.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Submitted. Paper 5: Manuscript.
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DeJong, David Henry. "The Sword of Damocles: Pima Agriculture, Water Use and Water Rights, 1848-1921". Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/195634.
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This study identifies the historical factors that impacted Pima agriculture, water use and water rights in south-central Arizona between 1848 and 1921. Federal land and resource policies, especially federal Indian policies, impacted the dynamics of Pima agriculture and water use during these crucial years when the federal government utilized economic liberalism to open the West to homesteading and facilitate the development of the region's vast resources.As an agricultural people, the Pima did not passively accept these policies and events. Rather, they proved adaptive, demonstrating their resourcefulness in important ways. In response to water deprivation and infringement of their water rights, the Pima reduced the amount of land they cultivated. While before 1880 they had increased their cultivated acreage and expanded their trade networks, in the years after they creatively found ways to keep land in production despite water shortages. As the water crisis deepened, the Pima abandoned their least productive lands. In the midst of great deprivation, they relocated (or abandoned) a number of villages and scores of fields in an attempt against great odds to maintain their agricultural economy. To make the most of their diminishing water resources, the Pima adapted by growing small grains such as wheat and barley, even when these crops no longer proved to be economically viable in Arizona. While not new to their crop rotation, the Pima relied almost exclusively upon these crops by the 1910s since they required considerably less water than others.Because the Pima had prior and paramount rights to the water and were wrongfully deprived of their rights to the use of water, their water rights struggle raised a metaphorical Damoclean sword above the heads of those non-Indian farmers who used the water. This study, therefore, focuses on the history of water use and agricultural production among the Pima Indians between 1848 and 1921 and argues that without infringement of their rights to water, the Pima would have equaled and perhaps surpassed the local agricultural economy.
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Kingdon, Lorraine B. "Havesting Snow In Water Shy Arizona". College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/295539.
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Dale, Don. "Harvest The Water, Reap The Rewards". College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/295556.
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Zanger, Maggy. "Potential Problems of Treated Waste Water". College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/295692.
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Sundin, Caroline, i Nicolina Lindblad. "Water and Agriculture in Uganda : Supporting a CLEW’s assessment". Thesis, KTH, Industriell ekologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-174878.
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Williams, Sarah Elizabeth. "The agriculture-water interface : policy integration and the environment". Thesis, University of Hull, 1997. http://hydra.hull.ac.uk/resources/hull:3490.
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Although current environmental policies may prove successful against narrowly defined criteria of economic, social or environmental sustainability, it is by no means certain that the sustainability of inter-dependent economic and environmental systems will be assured. In fact, policy intervention may result in the displacement of environmental problems to other media, times or places. Farmers are the focus for divergent forces of state, market and social regulation and in consequence their response, or more importantly non-response, to environmental policies cannot be assessed in isolation. This thesis explores these complex issues through analysis of the agriculture-water interface, focusing on the allocation and regulation of abstraction water for use as spray irrigation by farmers in the eastern counties of England. Adopting an interface-network methodology, the analysis traces the network of social relations which directly and indirectly influence the use and management of irrigation water and potential response to demand management policies, encompassing farmers' interaction with the NRA, food processing, manufacturing and retail firms as well as farmer representative groups. Risk and uncertainty play a central role shaping interaction not only between firms, but between firms and farmers as they attempt to reallocate the financial, production, legal and environmental risks associated with production. The analysis demonstrates how farmers' incorporation into the "quality projects" of the downstream food network critically distorts their response to demand management policies. This perpetuates a highly intensive system of agricultural production, contributing to the loss of landscape and wildlife habitat and diffuse pollution of ground and surface water sources. The analysis concludes by outlining an alternative agenda of action for the Environment Agency which focuses on promoting synergy between state and market forces of regulation. Only through addressing these issues will the integration of the environment and economy prove successful at the agriculture-water interface.
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Nan, Xi <1992>. "Constructed wetlands for water management and reuse in agriculture". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/8748/1/Nan_Xi_thesis.pdf.
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Global warming mainly induced by anthropogenic causes has already restricted the increase in agricultural productivity along with aggravating the conflict between water supply and demand. In this context, constructed wetlands (CWs) can be one of nature-based solutions for the treatment and reuse of unconventional wastewater sources. The aim of this research was to evaluate the performance of CWs in wastewater treatment (i.e., agricultural drainage water and domestic wastewater) and to explore the potential of their effluents for agricultural reuse. In order to achieve this goal, the work based on literature review and experimental approach was carried out. The findings showed that CWs can be an effective option for treating both agricultural drainage water (ADW) and domestic wastewater. It was also found that systems treating ADW can be effective even after a long period of operation. The treatment performance of CW systems is affected by the design and operational factors. For instance, the application of simple hydraulic structures and vegetation establishment can improve the pollutant removal efficiencies by increasing hydraulic retention time. Moreover, the addition of other technologies (e.g., UV treatment, anaerobic reactors) could further improve the quality of wastewater treated by single-stage CWs. In particular, it is strongly recommended to add special disinfection technologies to CW treatment systems to meet agricultural reuse standards since it was shown that the microbial loads often exceed the limits (e.g., E. coli).
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Ingami, Erika <1987>. "The Zionist Legacy: Water and Agriculture Management in Israel". Master's Degree Thesis, Università Ca' Foscari Venezia, 2012. http://hdl.handle.net/10579/2005.
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L‘elaborato si prefigge lo scopo di analizzare il legame esistente fra le aspirazioni dei pionieri sionisti, la fondazione dello Stato d’Israele e la politica odierna della gestione delle risorse idriche (con un focus specifico sul ruolo che l’agricoltura aveva e ancora oggi ha nell’economia e nella creazione dello Stato).
La tesi prende in esame alcune fasi centrali della storia d’Israele (e ancor prima della comunità ebraica in Palestina) dall’inizio del XX secolo sino ad oggi. Partendo da considerazioni di tipo ideologiche e storiche (la redenzione della terra e il lavoro nei campi) l’elaborato si muoverà su riflessioni di carattere economico e ambientale per poi determinare le dinamiche della relativa influenza che l’ideologia sionista ha avuto sulla gestione delle risorse idriche e sul settore agricolo.
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Ouellette, Kayla. "Agriculture, Environmental Restoration and Ecosystem Services: Assessing the Costs of Water Storage on Agricultural Lands in South Florida". Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5090.
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A large part of the environmental restoration required by the Comprehensive Everglades Restoration Plan calls for more water-storage on lands south of Lake Okeechobee in order to restore the natural water flows of the Everglades watershed. The Everglades Agricultural Area (EAA) can be used for increased water storage in order to relieve coastal estuaries of excess water in the rainy season. This water storage can deliver additional ecosystem services of soil retention and reduced CO2 emissions that could compensate farmers for the cost of water storage by increasing long term farm profitability. The goals of this study were 1) to quantify the environmental and economic trade-offs of different water storage scenarios using water-tolerant sugarcane cultivars, and 2) to quantify the amount of water storage possible in the EAA under different water storage scenarios. A mathematical model was developed to calculate soil depth, soil subsidence, depth to the water table, sugarcane production, farm return, water storage and carbon loss for three different sugarcane cultivars with different water-tolerances. A GIS tool is also developed to estimate the amount of water storage possible in the EAA. The study found that even though water-tolerant sugarcane cultivars experience higher yields and net returns than non-water-tolerant cultivars the water storage costs with these water tolerant cultivars was greater. Raising water tables on farm lands did have the environmental benefits of reduced soil subsidence, extended farm life and increased years of water storage. However total CO2 emissions rise from 14 to 136%. Results of the GIS analysis revealed that water storage capacity for a DWT of 61 cm is 1,404,562 ac-ft, 1,417,400 ac-ft for DWT 45 cm and 1,474,692 ac-ft for DWT 20 cm. The GIS analysis was also able to identify flow ways that could possibly carry water south from Lake Okeechobee and ultimately to the WCAs south of the EAA. These results show that raising water tables in the EAA to deliver the ecosystem service of expanded water storage is overall more costly, but yearly costs are very low. Therefore water storage on farmlands is an affordable interim method of water storage.
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Arslan, Awadis. "Modeling water quality for soils containing gypsic horizons". Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185231.
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A computer simulation model was developed to simulate the impact of irrigating soils containing gypsic horizons on soil water quality and percolated water quality. The model simulates saturated - unsaturated solute movement using the mixing cell approach to simulate dispersion and movement of soluble salts. Dissolution and precipitation of slightly soluble salts and the formation of ion pairs is considered as a function of temperature. Van Genuchten closed form equation is used to find soil water retention function. Finite difference method was applied to Richards equation for moisture movement simulation in the profile. The model predicts the concentration of the major cations and anions in each segment. The regression coefficients of the observed vs. simulated concentration of the major ions were higher than 0.961 in all the three replicates with slopes ranging between 0.717 and 0.940. Running the model at 1 and 41 °C showed significant differences in Ca, SO₄, and HCO₃ concentrations in the percolated water. However, the differences in Cl, Na, and Mg concentrations were not significant. The presence of high Ca and SO₄ concentrations in the irrigation water reduced gypsum solubility in soils containing a layer of gypsum compared with the presence of Mg and Cl in the irrigation water.
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McGinley, Susan. "Evaluating Contaminants in Colorado River Water". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2010. http://hdl.handle.net/10150/622078.
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Salazar, Moreno Raquel. "Multiple criteria analysis of economic, environmental and water use problems in an irrigation district of Mexico". Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/284229.
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The Alto Rio Lerma Irrigation District (ARLID), located in the state of Guanajuato in Mexico, is an agricultural area whose sustainability depends partially upon groundwater withdrawal for crop irrigation. Because of high pumping demands and current land-management practices, water levels in the regional groundwater aquifers have declined severely, resulting in aquifer overdraft. The potential adverse consequences of this overdraft cannot be overstated, as the long-term economic viability and environmental integrity of the region is threatened. In order to analyze this economic, environmental, and water use problems in this region, simulation of the agricultural system was performed and associated water use impacts quantified under different management scenarios. Linear programming identified the 12 optimal cropping patterns, and then multi-criteria decision-making methodologies were applied to rank and identify the best cropping pattern (satisficing solution). The GLEAMS model was used to simulate the amounts of water, nitrate, and pesticides in both runoff and percolation for each cropping pattern. In order to quantify the economic and environmental impacts of aquifer overdraft, two attributes were used; pumping costs and an aquifer exploitation coefficient. Three multiple criteria methods: Q-analysis, ELECTRE II, and the Range of Value Method, were evaluated and the latter method was selected to analyze the payoff matrix for the ARLID, where 12 alternatives, each with 13 attributes, were considered. The results show the best alternative for effectively balancing environmental with economic considerations was the farming practice, consisting of land leveling, growing vegetables such as red tomato, and controlled groundwater withdrawals to preserve aquifer sustainability. Low water availability does not necessarily reduce farmer's profits, if new water saving alternatives are applied, combined with more profitable crops. Given that ROV method only considers full compensation between objectives, this research contemplate an extension for the nonlinear case in order to assess the whole range of values of the objective function. The final findings suggest that the best methodology was to apply L1 in the lower levels and then L2 for the highest level in the hierarchy. In this manner, the partial compensation between objectives is considered and also the decrease in the uncertainty of alternatives selection.
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Watson, J., i M. Sheedy. "Crop Water Use Estimates". College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210312.
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Irrigation scheduling, by keeping track of irrigation applications, soil storage and crop water use, has been computerized by a number of different individuals. A key component of the computerized methods is the estimation of a reference crop evapotranspiration rate. Complaints about one such method, AZSCHED, led the authors to compare the reference crop evapotranspiration values calculated by AZSCHED with those calculated by a second procedure available used by AZMET. Results of the comparison indicated that no significant difference existed between methods, for either a traditionally "long season", or a contemporary "short season" growing period. AZSCHED did estimate crop water use to be about 5% - 8% more than AZMET, an amount that is not of importance considering the irrigation inefficiencies created by field non-uniformities. Experience by the authors indicates that inappropriate selection of irrigation efficiencies and/or soil water holding capacity may be the main cause of user complaints.
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Cowley, Robyn Anne. "The effect of changing water distribution from linear to point source on vegetation and soil following piping of an artesian bore in a semi-arid mulga paddock /". [St. Lucia, Qld.], 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16636.pdf.
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Nogueira, Saraiva João Paulo Prazeres de Sá. "Implications of water environmental policy for irrigated agriculture in Portugal". Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505302.
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This research develops a bio-economic modelling framework for the assessment of agricultural and water policy change implications for irrigated agriculture. It aims to contribute towards the implementation of the Water Framework Directive within the European Union, particularly in regard to the principles of cost recovery of water services and water demand management for irrigation.
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Ji, Xinde. "Essays on the Economics of Climate Change, Water, and Agriculture". Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/84941.
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In an era of global-scale climate change, agricultural production faces a unique challenge due to its reliance on stochastic natural endowments, including temperature, precipitation, and water availability for irrigation. This dissertation presents a series of essays to examine how agricultural producers react and adapt to challenges presented by climate change and scarce irrigation water allocated through the prior appropriation doctrine. The dissertation approaches the problem from three distinct perspectives: institutional differences, climate and water availability, as well as producers' expectation on future endowments.
Chapter 2 presents an institutional perspective, in which I investigate how different water allocation mechanisms within the prior appropriation doctrine result in differences in producers' crop allocation decisions. I find that water users in irrigation districts are able to plant more water-intensive crops than farmers outside irrigation districts.
Chapter 3 presents the interaction between nature and human systems, in which I examine how the physiological complementarity of temperature and water availability diffuses from crop yield (at the intensive margin) to crop allocation strategies (at the extensive margin). Using a theoretical model I show that the observed complementarity reflects a combination of two mechanisms: yield impact through physiological complementarity, and adaptation response through shifting crop allocation patterns. Using an empirical model, I find that farmers adapt to changing climate conditions by growing more profitable crop mixes when presented with more growing degree-days (GDD), precipitation and groundwater access.
Chapter 4 presents a behavioral perspective, in which I test how producers' expectation formation processes lead to short term over-adjustments to weather and water availability fluctuations. Using a fixed-effect regression on lagged weather and water realizations, I find that agricultural producers engage in a combination of cognitive biases, including the availability heuristic and the reinforcement strategy. Adopting these alternative learning mechanisms causes farmers to significantly over-react to more recent fluctuations in weather and water availability when making ex ante acreage and crop allocation decisions.Ph. D.
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Prazeres, de Sa Nogueira Saraiva Joao Paulo. "Implications of water environment policy for irrigated agriculture in Portugal". Thesis, Imperial College London, 2009. http://hdl.handle.net/10044/1/4365.
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This research develops a bio-economic modelling framework for the assessment of agricultural and water policy change implications for irrigated agriculture. It aims to contribute towards the implementation of the Water Framework Directive within the European Union, particularly in regard to the principles of cost recovery of water services and water demand management for irrigation. The bio-economic framework combines local agro-ecological with socio-economic elements, allowing for the introduction of biophysical relationships of irrigated agricultural production into the appraisal of policy instruments. This framework is used to investigate the comparative performance of water management policy instruments for irrigation, including volumetric pricing, flat pricing, a two-part tariff and water allotments. Implications of these water policy instruments are assessed in combination with agricultural market and policy scenarios, which are used to define the economic background in which water policies will operate. This operational framework is designed within a microeconomic context at the farm level that takes into account crop yield-water relationships, the revealed economic behaviour of farmers, as well as structural productive patterns of representative agricultural systems in two case study areas in the south of Portugal. This integrated approach provides a comprehensive understanding of the implications of agricultural and water policies on irrigated agriculture within the European Union, unravels conflicts and identifies synergies between these policies. Simulation of water policy instruments produced substantial differences in performance across farming systems, enforcement levels, and agricultural policy and market settings. Results suggest that water pricing, on its own, is not necessarily the most effective means for achieving the WFD water demand management and cost recovery objectives, and proposes that a policy mix combining economic with regulatory elements may be best designed to pursue these objectives with fewer detrimental consequences. This study highlights that conflicts between CAP and the WFD may result in losses of efficiency, policy efficacy and losses of welfare, that could be minimised by integrating both policy measures and objectives, in a coherent and combined approach, exploring synergies and coordinating efforts to overcome sources of conflict.
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Hammond, Wagner Courtney Ryder. "Governing Water Quality Limits In Agricultural Watersheds". ScholarWorks @ UVM, 2019. https://scholarworks.uvm.edu/graddis/1062.
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The diffuse runoff of agricultural nutrients, also called agricultural nonpoint source pollution (NPS), is a widespread threat to freshwater resources. Despite decades of research into the processes of eutrophication and agricultural nutrient management, social, economic, and political barriers have slowed progress towards improving water quality. A critical challenge to managing agricultural NPS pollution is motivating landowners to act against their individual farm production incentives in response to distant ecological impacts. The complexity of governing the social-ecological system requires improved understanding of how policy shapes farmer behavior to improve the state of water quality. This dissertation contributes both theoretically and empirically to NPS pollution governance by examining the impacts of water quality policy design on farmer nutrient management decision making and behavior.
In the first study, I theoretically contextualize the issue of agricultural NPS pollution in the broader discussion of environmental public goods dilemmas to suggest that an increased focus on the link between policy and behavior can improve sustainable resource management. I propose two empirical approaches to study the policy-behavior link in environmental public goods dilemmas: 1) explicit incorporation of social psychological and behavioral variables and 2) utilization of actor mental models, or perceptions of the world that guide decision making, to identify behavioral drivers and outcomes. In the second and third studies, I then use these approaches to examine how water quality policies for agricultural NPS collectively change farmer behavior to reduce nutrient emissions. The second chapter uses a quantitative, survey-based approach to examine the relationship between mandatory policy design and behavior change in New Zealand. I find that a shift to mandatory policy is not immediately associated with increased adoption of nutrient management practices, but the mandatory policy design is important for potential future behavior change and long-term policy support. In the third study, I combine qualitative methodology with network analysis of qualitative data to examine a spectrum of agricultural NPS pollution policies in Vermont, USA and Taupo and Rotorua, New Zealand. I use farmer mental models to examine behavior change within each of the regions, the perceived drivers of behavior change and perceived outcomes of the policy. In this study, farmers across all three regions cite mandatory water policy as a key behavioral driver, but in each region, policy design interacts with the social-ecological context to produce distinct patterns of behaviors and perceived outcomes. Taken together, this dissertation demonstrates that agricultural NPS pollution policy design must consider the interactions between policy and other social-ecological behavioral drivers in order to achieve long term water quality improvements.
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Kingdon, Lorraine B. "The Central Arizona Project: Water with a Bitter Twist". College of Agriculture, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/295716.
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Jalilov, Shokhrukh-Mirzo. "Impact of Rogun Dam on Downstream Uzbekistan Agriculture". Thesis, North Dakota State University, 2011. http://hdl.handle.net/10365/16332.
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Strains among the states of Central Asia caused by overuse of the region?s scarce water resources have been increasing in recent years. This is especially true for the relations between Tajikistan, upstream, and Uzbekistan, downstream, on the Amudarya River. Major controversy exists over constructing Rogun Dam on the Vakhsh River, a tributary of the Amudarya River. Construction of Rogun Dam, with a planned height of 335 m (1099 ft), began in 1976 but was stopped in 1991 with the breakup of the former Soviet Union. The intent of this dam is to supply Tajikistan with energy, but a side effect will be the changed flow regime of the Amudarya River to downstream states (especially Uzbekistan). The major impact will be on the agricultural sector of Uzbekistan. The objectives of this study are to estimate the monetary impacts of Rogun Dam and propose mitigation measures to minimize impacts. The study investigates the nature and extent of those impacts and indicates policy implications to mitigate negative consequences of the possible water shortage in summer by assessing the baseline situation and comparing that situation with future status-quo (no changes) level of water. Future water shortage could cost Uzbekistan annually over US $609 million economic loss in agriculture, reduce the country?s GDP by 2.2%, and result in 336,000 unemployed people. If Uzbekistan changes its present water use practice and increases water use efficiency, the future water shortage during irrigation periods will not as seriously affect the country?s economy, as adaptive management measures could cut the losses by 40%.
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Jones, Michael A. "Systems Modeling and Economic Analysis of Photovoltaic (PV) Powered Water Pumping Brackish Water Desalination for Agriculture". DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4265.
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Global growing demand for agricultural production has put increased pressure on freshwater resources in various global locations. Many areas have saline groundwater resources which have not been utilized for agriculture due to the economics associated with water pumping and desalination. Limited availability to electricity and high operational costs of diesel generators are major obstacles to utilization of these resources. Reduced costs associated with large-scale renewable energy have renewed interest in understanding the potential impacts of developing distributed photovoltaic (PV) powered water pumping and desalination systems for agriculture. In order to determine the economic feasibility of solar-powered water pumping and desalination for agriculture, an engineering system model that performs hourly simulations of direct-coupled PV pumping and desalination systems by integrating environmental resource data and industrial component performance data was developed. Optimization algorithms were created to identify the best membrane type, control method and reverse osmosis system configuration for a given set of locational parameters. Economic analysis shows that PV-powered systems are more economical than diesel-powered systems for water pumping, with water desalination costs for PV- and diesel-powered systems being comparable. Grid-powered systems are able to pump and desalinate water for a lower cost than PV or diesel for all cases evaluated. A sensitivity analysis is performed to generalize results for different input parameters and illustrate the impact of input variables on water unit costs. Several case studies in the Jordan Valley were evaluated to illustrate the economic viability of solar-based systems with simulation results including a direct comparison to diesel- and grid-connected alternatives. Results indicate that under fair environmental conditions and irrigating greenhouse vegetables, the PV-, diesel-, and grid-powered systems produce favorable internal rates of return of 40%, 84%, and 248%, respectively. Under poor environmental conditions and less profitable crops the PV-, diesel-, and grid-powered systems all result in negative internal rates of return, illustrating the need for optimal location and crop selection for system implementation.
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Wang, Shu-Tai. "The Freezing Behavior of Water as Influenced by Ice Cream Stabilizers /". The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487935125881971.
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Kivumbi, Dorian. "Decision support system for improved irrigation water management". Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301207.
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Zaikin, Andrey. "Economics of soil and water conservation in irrigated and dry lands agriculture". Online access for everyone, 2006. http://www.dissertations.wsu.edu/Thesis/Summer2006/a%5Fzaikin%5F072606.pdf.
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BassiriRad, Hormoz. "Influence of temperature on root water and ion transport and the subsequent effect on shoot water status and growth of barley and sorghum seedlings". Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185129.
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Short term root temperature treatments between 15 to 40°C at a constant air temperature produced a differential response in shoot growth of barley and sorghum seedlings. Maximum growth rate occurred at 25°C in barley and 35°C in sorghum. The stimulation of growth in barley in the suboptimal temperature ranges (15 to 25°C) was associated with both enhanced L(p) and Jᵢ whereas growth inhibition at elevated temperatures (>25°C) was associated with no changes in L(p), but was accompanied by a severe inhibition of solute fluxes suggesting that supraoptimal temperature inhibition of growth in barley is caused by limited ion and not water supply to the leaves. In sorghum, the enhanced shoot growth in the 15 to 25°C range coincided with stimulated L(p) and Jᵢ. Between 25 to 35° temperature induced enhancement of growth was mainly caused by enhanced L(p). In both plants even when root L(p) appeared to cause temperature induced changes in growth, the bulk leaf water, osmotic and turgor potential remained unaffected. It is suggested that when reduced water supply limits growth, undetectable changes in xylem water potential may mediate temperature response in root L(p) and growth. Temperature effects on ion transport across the root were found to be regulated at the site of ion release into the xylem (Φ(cx)) rather than the site of ion entry into the root (Φ(oc)). When ABA was added to the external solution, L(p) was enhanced but qualitative responses of Jᵢ and L(p) to changes in root temperature remained unchanged in barley. However, addition of ABA to the medium with sorghum roots caused a severe inhibition of solute fluxes at temperatures above 25°C which happened only when the temperature was raised above 35°C in the absence of ABA. The ABA study suggested that temperature induced changes in root transport properties of both plants were not mediated by ABA.
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Uribe-Chavez, Armando. "A numerical model and semi-analytic equations for determining water table elevations and discharges in non-homogeneous subsurface drainage systems". Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/289956.
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A free water surface finite element model was developed. The method was implemented with the Galerkin approach to solve the Laplace equation in the saturated region. It was developed in the object oriented Visual C ++ computer language to permit easy update and drawing of the adaptive mesh. For each time step, the new water table position was calculated based on flux across the water table, a Brooks-Corey equation mass balance for the unsaturated region, and an equation that calculates water table position for the saturated region. An equation was developed to calculate a drainage transfer coefficient, alpha, based on percentage of perforated area in the drain tube wall. The drainage transfer coefficient was incorporated into the finite element model as a Fourier boundary condition. To validate the finite element model, its results were compared with the Kirkham equation results for steady state recharge of three subsurface drainage systems. The finite element model was used to calibrate a semi-analytical frozen stream tube model for subsurface drainage of heterogeneous soils. The first step in the calibration procedure is to run the finite element model for steady state recharge and calculate the water table height divided by recharge rate (the stream tube resistance to flow) as a function of distance between drains. Least squares regression is used to fit a polynomial logarithmic equation, called the resistance function, to the stream tube resistance to flow vs. distance from the drain curve. A differential equation based on the principle of conservation of mass and application of Darcy's law to the frozen stream tube was solved to obtain an equation that calculates stream tube flow rate and final water table elevation as a function of the resistance function and initial water table elevation. An example was developed for a non-homogeneous subsurface drainage system to illustrate the use of the semi-analytical model to predict water table fall and discharge.
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Costa, Pedroso Rui Miguel [Verfasser]. "Dimensioning Branched Water Distribution Networks for Agriculture / Rui Miguel Costa Pedroso". Bonn : Universitäts- und Landesbibliothek Bonn, 2014. http://d-nb.info/1052101356/34.
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Robinson, Allan. "Integrated systems modelling of the interaction between water resources and agriculture". Thesis, Cranfield University, 1999. http://hdl.handle.net/1826/3903.
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Environmental problems associated with the use of water are inherently complex,
involving the interaction of several different systems. Further, there is often limited
data on the interaction, because of its location between disciplines. In order to study
these problems in a quantitative, policy relevant way, a numerical model is required that
integrates the different systems and is tailored to contain the processes important to the
interaction.
A numerical water resource system model is developed to study the problems associated
with the interaction between agriculture and water. The model integrates an
econometric model of farmer behaviour with a dynamic model of water flow and solute
transport. The Argolid valley in Greece represents an area where severe environmental
problems have arisen as a result of the overexploitation of groundwater for agriculture.
When applied to the Argolid valley the water resource system model reproduces the
evolution of the environmental problems that have arisen. It is then demonstrated that
the model can be used to investigate some future scenarios and policy options related to
the environmental problems that have developed.
The main contribution of this research is to demonstrate that a properly designed
numerical model that reproduces the dynamic interaction between human behaviour and
the physical environment can enable the exploration of the evolution of environmental
problems despite a lack of calibration data. Having achieved this the model can then be
used in a policy relevant way to investigate the implications from a range of different,
possible policy options.
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Alhassan, Abdulaziz (Abdulaziz Abdulrahman). "Computational design and optimization of infrastructure policy in water and agriculture". Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111500.
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Thesis: S.M., Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 87-90).
Investments in infrastructure tend to be associated with high capital costs, creating a necessity for tools to prioritize and evaluate different infrastructure investment options. This thesis provides a survey of computational tools, and their applicability in fine-tuning infrastructure policy levers, prioritizing among different infrastructure investment options and finding optimal sizing parameters to achieve a certain objective. First, we explore the usability of Monti Carlo simulations to project future water demand in Saudi Arabia and then, we use the outcome as an input to a Mixed Integer Linear Program (MILP) that investigates the feasibility of seawater desalination for agricultural irrigation under different water costing schemes. Further, we use numerical simulations of partial differential equations to study the conflicting interests between agricultural and municipal water demands in groundwater aquifer withdrawals and lastly we evaluate the use of Photo Voltaic powered Electro Dialysis Reversal (PV-EDR) as a potential technology to desalinate brackish groundwater through a multidisciplinary system design and optimization approach.
by Abdulaziz Alhassan.
S.M.
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Wenhold, FAM, M. Faber, Averbeke W. Van, A. Oelofse, Jaarsveld P. Van, van Rensburg WS Jansen, Heereden I. Van i R. Slabbert. "Linking smallholder agriculture and water to household food security and nutrition". Water SA, 2007. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000820.
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Promoting household food security and reducing malnutrition rates of a growing population with the same amount of water
is a challenge facing South African nutritionists and agriculturalists alike. Apart from non-food related effects of agriculture
in general, the crop and livestock production practices of the South African smallholder farmer may have nutritional implications,
primarily when practised on residential land and resulting in home consumption. Yet, few studies have systematically
investigated the impact thereof. It appears that crop diversification, gender issues and nutrition education are among the
important factors that strengthen the link between agriculture and nutrition. Since food production is the most water-intensive
activity in society, nutritional water productivity (i.e. nutrition per volume water) of foods and the nutritional water footprint
of diets should be investigated in order to achieve a sustainable solution. This implies that both the demand for a diet consisting
predominantly of water-productive plant products, as well as the supply thereof, be addressed.
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Modi, Albert T. "Water status and metabolite changes during seed development and germination in soybean /". The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488191667183902.
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Li, Qionfang. "An investigation of integrated management of irrigation systems for agriculture and aquaculture". Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268373.
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Ferguson, John N. "Natural variation of water use and water productivity in Arabidopsis thaliana". Thesis, University of Essex, 2017. http://repository.essex.ac.uk/19554/.
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Plant performance under reduced water availability has traditionally been assessed as drought resistance and more recently as water use efficiency (WUE). An extensive body of work has been established over the past 15 years where the natural variation of water use efficiency has been studied in the model species Arabidopsis thaliana (Arabidopsis). At the same time, a substantial degree of criticism has arisen with respect to the use of drought resistance and WUE as measures of plant performance, due to the lack of relatedness of these parameters to reproductive performance, i.e. yield. The work in this thesis is centered on understanding the physiological and genetic basis of water use and water productivity as alternative measures of plant performance under the context of reduced water availability. The first part of this study describes an extensive assessment of the natural variation of water use and water productivity in Arabidopsis in relation to numerous key physiological, phenological, and developmental parameters. Furthermore, this work concisely relates plasticity of key traits to historical climatic variation. A fundamental aspect of this work was the clarification that it is possible to estimate long term water use to a high degree of accuracy based on short term water use, i.e. soil drying rate, and flowering time. Flowering time was demonstrated to be the predominant driver of vegetative performance and water use, however it appeared to be genetically uncoupled from reproductive performance. This is in contrast to previous work that suggests WUE, measured as the ratio of C12 to C13 isotopes (δ13C), is positively associated with flowering time. Additionally, it was demonstrated that multiple commonly employed proxies of reproductive performance including total biomass, WUE, and flowering time, were not sufficient at predicting seed yield in Arabidopsis across multiple environments. The second part of this study involved the genetic dissection of water use and productivity related traits in Arabidopsis through a quantitative trait loci (QTL) mapping study and a genome wide association study (GWAS). QTL mapping using a recombinant inbred line (RIL) population developed from the ecotypes Col-0 and C24 revealed two key flowering time genes, FLOWERING LOCUS C (FLC) and FRIGIDA (FRI), as key regulators of water use. It was demonstrated that a combination of non-functional alleles of both FLC and FRI reduced long term water use via a shorted life cycle, which is again in contrast to previous work relating to the genetic dissection of WUE in Arabidopsis. Crucially, it was observed that reduced water use mediated in this fashion did not detrimentally impact upon reproductive performance. GWAS was employed subsequent to the QTL mapping in order to identify candidate genes underlying the variation for productivity as a unique trait and also as a factor of water use, i.e. water productivity. GWAS identified multiple promising candidate genes that potentially underlie the heritable genetic variation for flowering time, water use, and water productivity.
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Amer, Saud Abdulaziz. "Spectral response of sweet corn, squash, and beans to nitrogen, zinc and water treatments". Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/298785.
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The study consisted of six experiments conducted to examine the spectral response of different varieties of corn (Zea mays), squash (Cucurbita pepo) and bean (Phaseolus vulgaris) under variable zinc (Zn), nitrogen (N) and water treatments. Five of these experiments were conducted in the greenhouse during 1988 and 1989. The sixth experiment was conducted in the field during the summer of 1989. Ground-based, remotely sensed data were collected over plant canopies during the growing period, using an Exotech Model 100 AX hand-held radiometer. The Exotech offers filter sets which match the thematic mapper (TM) bands 1 through 4 (0.45-0.52, 0.52-0.60, 0.63-0.69, and 0.76-0.90 μm). Canopy spectral reflectance and derived vegetation indices showed their ability to significantly discriminate among varieties and variable treatments. Soil adjusted vegetation index (SAVI) mimics the normalized difference vegetation index (NDVI) and transformation normalized difference vegetation index (TNDVI) and exhibited all the characteristics of the NDVI curve when there were no soil influences (a single soil type). Red and near infrared (NIR) reflectance factors exhibited ability in monitoring crop growth and development. The TNDVI showed its superiority in detecting variations and in correlating with ground truth data (biomass cover percent). However, the study showed that remotely sensed data were sensitive to variations (varieties and treatments), but the data did not differentiate between them, unless supported with ground truth data.
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Roth, Robert L., i Byrant R. Gardner. "Asparagus Response to Water and Nitrogen". College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/214273.
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The relationships of asparagus yields to varying levels of water and nitrogen were determined. Maxinuem yields of 345, 560 and 300 crates/acre were produced for asparagus crowns that were 3, 4 and 5 years old, respectively. A total seasonal water depletion rate of 98 inches was calculated for the fern growing season. Optimum nitrogen applications were estimated at approximately 350 -400 lb/ac.
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Moolman, Christina Elizabeth. "Modeling the marginal revenue of water in selected agricultural commodities a panel data approach /". Diss., Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-09162005-094852.
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