This is a thesis about water efficiency, a particular set of practices in the water industry of England and Wales designed to reduce end-use water demand in homes and businesses. Broadly, the thesis aims to understand how water efficiency activities organised and funded by water companies might more effectively support the development of sustainable patterns of domestic demand, in order to contribute to long-term sustainable water management. To achieve this aim, mixed qualitative methods are used to; a) evaluate the extent to which two non-conventional water efficiency activities engage with the collective elements of everyday consumption that existing research deems necessary to steer demand (Strengers, 2012, Macrorie et al., 2014, Shove, 2014, Geels et al., 2015); b) develop a conceptual understanding of demand management as a professional practice, to understand how Water Company activities are shaped, sustained and stifled; and c) develop an understanding of what future water efficiency activities might look like that take account of the findings from this research. Central to this research and analysis is the notion of 'collective', a term that denotes a conceptual perspective on demand that departs from a focus on individuals, towards the shared social, technological and natural relations that structure everyday activity (Browne et al., 2014). The analysis uses this notion of collectives to examine the impacts and limitations of Save Water Swindon, a large-scale 'whole-town' approach to water efficiency (Case Study 1); to explore how Care for the Kennet contributes to demand management by reconfiguring relations between water in the home and water in the river (Case Study 2); and to uncover the collective context of the professional practices of managing demand (Case Study 3). The findings illustrate that demand is shaped by routines that extend far beyond the spaces in which water is used, both intentionally and unintentionally, and therefore highlight a distributed web of people and practices that might be involved in demand management. The findings from these empirical enquiries are used to as the basis to work with the water industry to reimagine interventions that engage in the collective context of demand, and elicit conceptual understandings of the processes and actors involved in governing social change. Overall, the approach taken in this thesis demonstrates the vitality of practice-based enquiry that provides deep analytical detail to better understand the mundane yet complex processes that sustain everyday water use. Supplementing the analysis with ideas from a variety of social science disciplines and working alongside the water industry, facilitated by the CASE studentship, pushes the analysis beyond the confines of domestic practices typical of practice-based research. Subsequently this research offers contributions to policy, practice and theoretical developments as it explores the intersections between demand and professional practices and local environments, evaluates interventions, examines practices of demand management, and unravels the possibilities for future intervention. Consequently, though focused on water management in the UK, this research offers insights for other resource agendas and regional contexts, expanding discussions in these spaces to think creatively about avenues for future policy and management practice.

Made available in DSpace on 2014-08-13T14:51:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-06-27Bitstream added on 2014-08-13T17:59:33Z : No. of bitstreams: 1 000776732.pdf: 2655431 bytes, checksum: 22c3362b8f558ed929854d3c4a527e66 (MD5) / O Arroz é o cereal mais consumido no mundo e o método de irrigação por inundação é o mais empregado devido às condições agronômicas criadas que favorecem à obtenção de maior produtividade mas também a maior consumo de água. Portanto o objetivo deste estudo foi avaliar o consumo de água no sistema de irrigação com distribuição de múltipla entrada na cultura do arroz, a qual foi desenvolvido durante a safra agrícola 2013/14 na área da várzea do Departamento de Engenharia Rural da Faculdade de Ciências Agronômicas da Universidade Estadual Paulista “Júlio de Mesquita Filho”, no campus Botucatu-SP. A irrigação do arroz no experimento foi realizada pelo método de irrigação por inundação intermitente dos tabuleiros e com altura de lâmina de água de 10 cm. A análise do consumo de água foi mediante a comparação dos componentes de entrada e saída do balanço hídrico em arroz irrigado com dois tratamentos, denominados MIRI para o tratamento de irrigação por distribuição de múltipla entrada e CONV para o tratamento de inundação convencional. Os componentes de entrada para cada tratamento foram a precipitação pluvial e lâmina de água de irrigação e os componentes de saída, a evapotranspiração da cultura (ETc), a percolação profunda e o fluxo lateral. Para a medição da precipitação pluvial foi usado um pluviômetro mediante leituras diárias e para a medição da lâmina de água aplicada na irrigação foram utilizados hidrômetros de vazão nominal de 15 m3 h-1. O cálculo diário da ETc foi pelo método de tanque evaporímetro classe A, as perdas de água por percolação profunda e fluxo ... / Rice is the most consumed cereal worldwide and flood irrigation method is the most used due to the agronomic conditions that not only favor higher productivity, but also higher water consumption. Therefore, the objective objective of this study was to evaluate water consumption in an irrigation system with multiple inlet distribution in the rice culture. The work was developed during crop 2013/14 in the lowland area of the Rural Engineering Department at the School of Agronomical Sciences of São Paulo State University “Júlio de Mesquita Filho” University, Botucatu Campus- São Paulo. The method of irrigation for rice culture used in the experiment was the intermittent flood with water depth flood of 10 cm. The analysis of water consumption was made by comparing the input and output components of the water balance in the irrigated rice in two treatments, called MIRI for the irrigation treatment by distribution of multiple inlet, and CONV for the conventional flooded treatment. Input components for each treatment were rainfall and irrigation; and output components were the crop evapotranspiration (ETc), deep percolation and lateral flow. Rainfall measurement was made by a Rain Gauge through daily readings. Measuring the amount irrigation water applied was made by flowmeters of nominal flow rate of 15 m3 h–1. The daily calculation of ETc was made by the class A evaporimeter tank method; water losses by deep percolation, and lateral flow was made by measuring the elevation of the water table and the relation between the irrigated perimeter area and height of the levee, respectively. To determine the water content in the soil the Time Domain Reflectometry method was used, measuring on field with TDR100 equipment. The total water consumption in the treatment MIRI was of 1.754,8 mm, which is 8,62 % lower than CONV treatment, 4 mainly due to decreased irrigation water applied, which was 9,75% lower ...

Orientador: Rodrigo Máximo Sánchez Román / Banca: João Carlos Cury Saad / Banca: Marconi Batista Teixeira / Resumo: O Arroz é o cereal mais consumido no mundo e o método de irrigação por inundação é o mais empregado devido às condições agronômicas criadas que favorecem à obtenção de maior produtividade mas também a maior consumo de água. Portanto o objetivo deste estudo foi avaliar o consumo de água no sistema de irrigação com distribuição de múltipla entrada na cultura do arroz, a qual foi desenvolvido durante a safra agrícola 2013/14 na área da várzea do Departamento de Engenharia Rural da Faculdade de Ciências Agronômicas da Universidade Estadual Paulista "Júlio de Mesquita Filho", no campus Botucatu-SP. A irrigação do arroz no experimento foi realizada pelo método de irrigação por inundação intermitente dos tabuleiros e com altura de lâmina de água de 10 cm. A análise do consumo de água foi mediante a comparação dos componentes de entrada e saída do balanço hídrico em arroz irrigado com dois tratamentos, denominados MIRI para o tratamento de irrigação por distribuição de múltipla entrada e CONV para o tratamento de inundação convencional. Os componentes de entrada para cada tratamento foram a precipitação pluvial e lâmina de água de irrigação e os componentes de saída, a evapotranspiração da cultura (ETc), a percolação profunda e o fluxo lateral. Para a medição da precipitação pluvial foi usado um pluviômetro mediante leituras diárias e para a medição da lâmina de água aplicada na irrigação foram utilizados hidrômetros de vazão nominal de 15 m3 h-1. O cálculo diário da ETc foi pelo método de tanque evaporímetro classe A, as perdas de água por percolação profunda e fluxo ... / Abstract: Rice is the most consumed cereal worldwide and flood irrigation method is the most used due to the agronomic conditions that not only favor higher productivity, but also higher water consumption. Therefore, the objective objective of this study was to evaluate water consumption in an irrigation system with multiple inlet distribution in the rice culture. The work was developed during crop 2013/14 in the lowland area of the Rural Engineering Department at the School of Agronomical Sciences of São Paulo State University "Júlio de Mesquita Filho" University, Botucatu Campus- São Paulo. The method of irrigation for rice culture used in the experiment was the intermittent flood with water depth flood of 10 cm. The analysis of water consumption was made by comparing the input and output components of the water balance in the irrigated rice in two treatments, called MIRI for the irrigation treatment by distribution of multiple inlet, and CONV for the conventional flooded treatment. Input components for each treatment were rainfall and irrigation; and output components were the crop evapotranspiration (ETc), deep percolation and lateral flow. Rainfall measurement was made by a Rain Gauge through daily readings. Measuring the amount irrigation water applied was made by flowmeters of nominal flow rate of 15 m3 h-1. The daily calculation of ETc was made by the class A evaporimeter tank method; water losses by deep percolation, and lateral flow was made by measuring the elevation of the water table and the relation between the irrigated perimeter area and height of the levee, respectively. To determine the water content in the soil the Time Domain Reflectometry method was used, measuring on field with TDR100 equipment. The total water consumption in the treatment MIRI was of 1.754,8 mm, which is 8,62 % lower than CONV treatment, 4 mainly due to decreased irrigation water applied, which was 9,75% lower ... / Mestre

Doctor of Philosophy / Department of Animal Sciences and Industry / Megan Rolf / In the future, water may not be as readily available due to an increase in competition from a growing human population, wildlife, and other agricultural sectors. To better understand water demands in the beef industry, water intake has to be accurately measured. It also critical to understand if water intake is a heritable trait and to determine its relationship to other production traits. This dissertation examines the number of days to accurately measure water intake in beef cattle, how to predict water intake in beef cattle using individual intakes, and estimates genetic parameters for water intake, dry matter intake (DMI), average daily gain (ADG), water efficiency measures, feed efficiency measures, and carcass traits. Study 1 investigates the test duration required to accurately measure water intake. Water intakes were collected over 70 d and shortened test periods (7 day intervals) were correlated with the full 70 day test to determine the minimum number of days required to accurately measure water intake. Water intake can be collected over a 35 to 42-day test period, with a minimal decrease in accuracy. Study 2 developed a water intake prediction equation that included different weather variables and average daily temperature (TAVG), average relative humidity (HVAG), solar radiation (SRAD), and wind speed (WSPD). Water intakes and feed intakes on individual animals were collected over a 70-day period along with (TAVG), (HVAG), (SRAD), (WSPD) for each day. Five different prediction equations were developed: summer, winter, slick bunk feed management, ad libitum feed management, and overall. All models included variables of DMI, metabolic mid test weight, TAVG, HAVG, SRAD, and WSPD, with R-squared values ranging from 0.34 to 0.41. Study 3 investigated the relationships between water intake and DMI, ADG, and water and feed efficiency traits. Variance components and genetic correlations were estimated using single-step genomic best linear unbiased prediction (GBLUP), incorporating genotypes on approximately 150,000 single nucleotide polymorphisms. Water intake was moderately heritable (0.39) and had moderate genetic correlations with DMI and residual feed intake, high genetic correlations with residual water intake, water to gain ratio, and feed to gain ratio, and had a low genetic correlation with ADG. Study 4 investigated the relationship between water intake and carcass traits. Single-Step GBLUP was used to estimate variance components and genetic correlations between water intake and carcass traits. Similar to study 3, water intake was moderately heritable (0.42). Water intake was moderately correlated with hot carcass weight (0.38), back fat (0.36), yield grade (0.29), and final body weight (0.29), but had a low genetic correlation with longissimus muscle area (0.08) and marbling (0.17). More research must be done to determine the relationships between water intake and other economically important traits in beef cattle and to better understand how environment and genetic background affect water intake. Improvements in water efficiency could decrease the amount of water cattle consume and assist producers in managing on-farm water resources during times of water scarcity.

Miami-Dade County implemented a series of water conservation programs, which included rebate/exchange incentives to encourage the use of high efficiency aerators (AR), showerheads (SH), toilets (HET) and clothes washers (HEW), to respond to the environmental sustainability issue in urban areas. This study first used panel data analysis of water consumption to evaluate the performance and actual water savings of individual programs. Integrated water demand model has also been developed for incorporating property’s physical characteristics into the water consumption profiles. Life cycle assessment (with emphasis on end-use stage in water system) of water intense appliances was conducted to determine the environmental impacts brought by each practice. Approximately 6 to 10 % of water has been saved in the first and second year of implementation of high efficiency appliances, and with continuing savings in the third and fourth years. Water savings (gallons per household per day) for water efficiency appliances were observed at 28 (11.1%) for SH, 34.7 (13.3%) for HET, and 39.7 (14.5%) for HEW. Furthermore, the estimated contributions of high efficiency appliances for reducing water demand in the integrated water demand model were between 5 and 19% (highest in the AR program). Results indicated that adoption of more than one type of water efficiency appliance could significantly reduce residential water demand. For the sustainable water management strategies, the appropriate water conservation rate was projected to be 1 to 2 million gallons per day (MGD) through 2030. With 2 MGD of water savings, the estimated per capita water use (GPCD) could be reduced from approximately 140 to 122 GPCD. Additional efforts are needed to reduce the water demand to US EPA’s “Water Sense” conservation levels of 70 GPCD by 2030. Life cycle assessment results showed that environmental impacts (water and energy demands and greenhouse gas emissions) from end-use and demand phases are most significant within the water system, particularly due to water heating (73% for clothes washer and 93% for showerhead). Estimations of optimal lifespan for appliances (8 to 21 years) implied that earlier replacement with efficiency models is encouraged in order to minimize the environmental impacts brought by current practice.

Please read the abstract (Synopsis) in the section, 00front of this document / Dissertation (MEng (Environmental Engineering))--University of Pretoria, 2008. / Chemical Engineering / MEng / unrestricted

O setor sucroalcooleiro encontra-se em plena expansão no país, incluindo áreas consideradas marginais, principalmente no que diz respeito à disponibilidade hídrica. O estabelecimento da cultura no campo é fundamental para o sucesso da atividade agrícola, uma vez que define parte do potencial de produção, sendo que o déficit hídrico nessa fase pode afetar significativamente o stand de plantas. Dessa forma, o presente trabalho teve por objetivo quantificar os níveis de déficit hídrico que comprometem o desenvolvimento inicial da cana-de-açúcar, para diferentes profundidades de solo (níveis de disponibilidade hídrica). O experimento foi conduzido na área de pesquisa do Departamento de Engenharia de Biossistemas na Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP) em ambiente protegido (casa de vegetação). O solo utilizado foi classificado como Latossolo Vermelho Amarelo, textura franco arenosa, denominado Série Sertãozinho. Foram utilizadas caixas de cimento amianto com capacidade de 100 litros, preenchidas com diferentes camadas de pedra brita nº 02, e solo, simulando profundidades de 10, 20, 30 e 40 cm. Os níveis de déficit hídrico foram representados pela evapotranspiração de referência acumulada de 0, 40, 80, 120, 160, 200, 240 e 280 mm, desde o plantio até o retorno da irrigação, estando a umidade inicial do solo na capacidade de campo. O sistema de irrigação utilizado foi por gotejamento e o manejo da irrigação com base em tensiometria. O delineamento experimental em blocos ao acaso (DBC) no esquema fatorial 4 x 8, totalizou 32 tratamentos, sendo a parcela experimental representada por uma caixa contendo, inicialmente, seis gemas de cana-de-açúcar. Observou-se que a umidade do solo na capacidade de campo na ocasião do plantio é suficiente para promover a brotação e emergência das mudas, independente do nível de déficit hídrico imposto posteriormente. Para profundidades de solo de 10 e 20 cm, nível de déficit hídrico de 160 mm de ET0ac provocou a morte total das plantas, enquanto que para profundidades de 30 e 40 cm, isto ocorreu com nível de 200 mm de ET0ac. Nível de déficit hídrico de 40 mm de ET0ac já é suficiente para reduzir, de forma significativa, o desenvolvimento da planta, independente da profundidade de solo. Entretanto, em condições desfavoráveis de plantio (a 10 e a 20 cm), o efeito negativo do déficit hídrico sobre o desenvolvimento da planta é ainda maior. Além deste efeito, a imposição do déficit hídrico também causou mudança no padrão de crescimento da planta, sendo expresso pela maior relação raiz - parte aérea. A eficiência no uso da água na fase inicial da cultura foi reduzida significativamente com o déficit hídrico e a redução da profundidade do solo explorada pelo sistema radicular, apresentando valores entre 0,16 e 3,21 g L-1. / Sugar and ethanol industry is booming in Brazil, including marginal areas, especially those related to water availability. The establishment of the crop in the field is fundamental to the success of this intensive agriculture, since it defines the baseline of the potential production. Water deficit at this stage can significantly affect plant stand. This study aimed to quantify water deficit levels that undertake the initial development of cane sugar, for different soil depths (levels of water availability). The experiment was conducted in the research area of the Biosystems Engineering Department at the School of Agriculture \"Luiz de Queiroz\" (ESALQ / USP) under greenhouse conditions. The soil was classified as Red-Yellow Latosol, sandy loam, called Sertãozinho Series. It was used cement boxes with a capacity of 100 liters, filled with different layers of nº 02 gravel, and soil, simulating porous media depths of 10, 20, 30 and 40 cm. The levels of water deficit were represented by the reference evapotranspiration accumulated (ET0ac) of 0, 40, 80, 120, 160, 200, 240 and 280 mm from planting until the return of irrigation, with the initial soil moisture at field capacity. Drip irrigation system and tensiometers were used to control soil moisture. The experiment was carried out under randomized block design (RBD) in a factorial scheme of 4 x 8, totalizing 32 treatments, being the experimental unit represented by a box containing six gems of sugar cane initially. Maintaining soil moisture at field capacity at planting time is sufficient to promote sprouting and emergence of seedlings, regardless of water deficit level following. For soil depths of 10 and 20 cm, water deficit level of 160 mm ET0ac caused total death of the plants, while soil depths between 30 and 40 cm, this occurred with a higher level of 200 mm ET0ac . Water deficit level of 40 mm ET0ac is enough to reduce significantly the aerial development of sugar cane plants, regardless of soil depth. However, under unfavorable planting conditions (10 and 20 cm soil preparation), the negative effect of drought on plant development is pronounced. In addition to this effect, the imposition of water deficit also caused changes in the plant growth rate that was expressed by a higher relationship root - aboveground biomass. Water use efficiency in the initial phase of sugar cane crop was significantly reduced with water deficit and the reduction of soil depth explored by the root system, with values ranging from 0,16 to 3,21 g dry mass L-1 of water.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Estudar a eficiÃncia do uso da Ãgua (EUA), a eficiÃncia econÃmica e os indicadores de rentabilidade na cultura do arroz (Oryza sativa, L.), foram os principais objetivos deste trabalho, realizado no PerÃmetro Irrigado de Morada Nova, CearÃ, no perÃodo de julho a dezembro de 2003. Estabeleceu-se a cultura do arroz cultivar EPAGRI 109, em unidades de solo com texturas areia-franca, franca e argilo-siltosa, sendo esta, em duas Ãreas, as quais denominaram-se I e II. Utilizaram-se calhas Parshall e sifÃes de plÃstico como instrumentos para mediÃÃo e aplicaÃÃo de Ãgua aos tabuleiros. O sistema de irrigaÃÃo utilizado foi inundaÃÃo. Os dados utilizados na anÃlise econÃmica foram de levantamentos de custos e receitas pertinentes à cada uma das unidades avaliadas. O perÃodo de irrigaÃÃo do cultivo de arroz para as condiÃÃes de solo e clima no Distrito de IrrigaÃÃo Morada Nova situa-se em torno de 120 dias, perÃodo este que deve ser tomado como referÃncia para o planejamento da irrigaÃÃo. A eficiÃncia de uso da Ãgua para os solos de textura leve apresentou valores mÃdios de 0,2 kg.m-3; jà para os solos de textura pesada, de 0,43 kg.m-3. A eficiÃncia de aplicaÃÃo de Ãgua na unidade textural argilo-siltosa, solo adequado ao cultivo de arroz apresentou um valor mÃdio de 66%. Na unidade textural areia franca, porÃm, solo sem aptidÃo ao cultivo do arroz, a eficiÃncia de aplicaÃÃo foi apenas de 35%, considerando-se em ambos os casos, somente os eventos de irrigaÃÃo sem dÃficit. A rentabilidade lÃquida de cada mil m3 , utilizando a metodologia de cobranÃa de Ãgua derivada e aplicada, mostrou-se superior nos solos argilo-siltosos com valores entre R$ 179,0 e R$ 94,0, enquanto os solos de textura mais leve esta rentabilidade nÃo ultrapassou os R$ 58,0. A receita lÃquida obtida em 1,0 ha de arroz na unidade textural areia franca (R$1.900,00), comparativamente ao valor obtido na unidade textural argilo-siltosa (R$2.400,00), incentiva o cultivo de arroz em solos sem aptidÃo para a cultura, porquanto o sistema de cobranÃa de Ãgua atualmente em vigor, leva em consideraÃÃo a Ãrea irrigada e nÃo o volume de Ãgua aplicada. A anÃlise da rentabilidade nas unidades texturais areia franca e argilo-siltosa, demonstrou a viabilidade do cultivo do arroz para ambas as unidades, em base aos critÃrios convencionais da anÃlise de investimento, porÃm, simulando-se uma remuneraÃÃo mensal do produtor no valor de R$ 240,0, o plano de cultivo na unidade textural areia-franca à inviÃvel, conforme os resultados obtidos: relaÃÃo benefÃcio custo (B/C) 0,98; valor presente lÃquido (VPL) -603,9 e taxa interna de retorno (TIR) 3,5%. Na unidade textural argilo-siltosa, porÃm, os indicadores se mostraram viÃveis: B/C 1,145, VPL R$ 4.204,1 e TIR 60,33%. / The main objective of this study was to determine the water use efficiency, the economic efficiency and the profit indexes for rice (Oryza sativa, L.) in the Morada Nova Irrigation District, state of CearÃ, Brazil, from July to December, 2003. EPAGRI 109 cultivar was cropped in three different soil units: sandyloam, silt and clay loam, the last two called units I and II, respectively. Parshall flumes and siphon tubes were used to measure and apply water to the field basins. The irrigation system used was basin irrigation (inundation). Data used for the economical analysis were obtained from costs and revenues surveyed in each plot evaluated. Irrigation period for planning for the soil and climate conditions of Morada Nova was 120 days. The water use efficiency for sandy soils presented average values of 0.2 kg.m-3; in the case of heavy soils such value was 0.43 kg.m-3. The water application efficiency for clay-loam soils was 66% in average, whereas for sandy-loam was 35%, considering, in both cases, irrigation without deficit. Net profit for a thousand cubic meter, using diverted and applied water methodology, showed superiority for clay-loam soils with values between R$179,00 and R$94,00, while for sandy soils the values were less than R$58,00. Profit analysis for sandy-loam and clay-loam showed feasibility for both soil units, based on conventional criteria of investment analysis, but considering in the simulation a minimum wage of R$240,00/worker, crop plan for the sandy-loam unit was not feasible, according to the obtained results: cost-benefit relation (B/C) equal to 0.98; net present value (VPL) of â 603.9 and âinternal rate of returnâ (TIR) equal to 3.5%. For the case of clay-loam soil the indexes presented feasibility: B/C = 1.145; VPL = R$4.204,10 and TIR = 60.33%.

Climate extremes, in particular droughts are significant driving forces towards riverine and terrestrial ecosystems disturbance. Drought impacts on stream ecosystems include losses that can either be direct (e.g. destruction of habitat for aquatic species) or indirect (e.g. deterioration of water quality, soil quality, and increased chance of wildfires). This study investigates hydrological and agricultural droughts and their recovery durations. For the riverine ecosystems, this study combines hydrologic drought and water quality changes during droughts and represents a multi-stage framework to detect and characterize hydrological droughts, while considering water quality parameters. Hydrological droughts are categorized into three stages of growth, persistence, retreat, and water quality variables (i.e., water temperature, dissolved oxygen concentration, and turbidity) are utilized to further investigate drought recovery. The framework is applied to 400 streamflow gauges across the Contiguous United States (CONUS) over the study period of 1950-2016. The framework is assessed and validated based on three drought events declared by the state of California in 2002, 2008, and for the 2012 US drought, which affected most of the nation. Results reveal the duration, frequency, and severity of historical droughts in various regions, additionally, duration of each stage of drought (i.e., growth, persistence, and retreat) is also assessed and the spatial patterns are diagnosed across the CONUS. Varied drought recovery durations are perceived for different water quality variables, and in general, it takes about two more months for water quality variables to recover from a drought, following the hydrological drought termination. For the terrestrial ecosystem, this study evaluated drought impacts on gross primary productivity (GPP), evapotranspiration (ET), and water use efficiency (WUE = GPP/ET) of different terrestrial ecosystems over the CONUS, as well as the drought-recovery during the period of 2000 to 2014. The response of WUE to drought showed large differences in various regions and biomes. WUE for arid ecosystems typically showed a positive response (increase) to drought, whereas WUE for humid ecosystems showed both positive and negative response to drought. The results revealed that WUE is correlated with drought severity, and for more severe droughts, WUE changes more significantly. Furthermore, terrestrial drought recovery shows a positive correlation with drought severity and in regions that experienced more severe drought episodes, ecosystem requires longer period to recover.

COLARES, Daniel Santana. Análise técnico-econômica do cultivo do arroz no perímetro irrigado Morada Nova, Ceará. 2004. 58 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Fortaleza-CE, 2004. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-06-20T12:57:34Z No. of bitstreams: 1 2004_dis_dscolares.pdf: 448942 bytes, checksum: 78b6b3820fccc6db2bddef9b9ec5db7a (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-06-20T13:00:02Z (GMT) No. of bitstreams: 1 2004_dis_dscolares.pdf: 448942 bytes, checksum: 78b6b3820fccc6db2bddef9b9ec5db7a (MD5) / Made available in DSpace on 2016-06-20T13:00:02Z (GMT). No. of bitstreams: 1 2004_dis_dscolares.pdf: 448942 bytes, checksum: 78b6b3820fccc6db2bddef9b9ec5db7a (MD5) Previous issue date: 2004 / The main objective of this study was to determine the water use efficiency, the economic efficiency and the profit indexes for rice (Oryza sativa, L.) in the Morada Nova Irrigation District, state of Ceará, Brazil, from July to December, 2003. EPAGRI 109 cultivar was cropped in three different soil units: sandyloam, silt and clay loam, the last two called units I and II, respectively. Parshall flumes and siphon tubes were used to measure and apply water to the field basins. The irrigation system used was basin irrigation (inundation). Data used for the economical analysis were obtained from costs and revenues surveyed in each plot evaluated. Irrigation period for planning for the soil and climate conditions of Morada Nova was 120 days. The water use efficiency for sandy soils presented average values of 0.2 kg.m-3; in the case of heavy soils such value was 0.43 kg.m-3. The water application efficiency for clay-loam soils was 66% in average, whereas for sandy-loam was 35%, considering, in both cases, irrigation without deficit. Net profit for a thousand cubic meter, using diverted and applied water methodology, showed superiority for clay-loam soils with values between R$179,00 and R$94,00, while for sandy soils the values were less than R$58,00. Profit analysis for sandy-loam and clay-loam showed feasibility for both soil units, based on conventional criteria of investment analysis, but considering in the simulation a minimum wage of R$240,00/worker, crop plan for the sandy-loam unit was not feasible, according to the obtained results: cost-benefit relation (B/C) equal to 0.98; net present value (VPL) of – 603.9 and “internal rate of return” (TIR) equal to 3.5%. For the case of clay-loam soil the indexes presented feasibility: B/C = 1.145; VPL = R$4.204,10 and TIR = 60.33%. / Estudar a eficiência do uso da água (EUA), a eficiência econômica e os indicadores de rentabilidade na cultura do arroz (Oryza sativa, L.), foram os principais objetivos deste trabalho, realizado no Perímetro Irrigado de Morada Nova, Ceará, no período de julho a dezembro de 2003. Estabeleceu-se a cultura do arroz cultivar EPAGRI 109, em unidades de solo com texturas areia-franca, franca e argilo-siltosa, sendo esta, em duas áreas, as quais denominaram-se I e II. Utilizaram-se calhas Parshall e sifões de plástico como instrumentos para medição e aplicação de água aos tabuleiros. O sistema de irrigação utilizado foi inundação. Os dados utilizados na análise econômica foram de levantamentos de custos e receitas pertinentes à cada uma das unidades avaliadas. O período de irrigação do cultivo de arroz para as condições de solo e clima no Distrito de Irrigação Morada Nova situa-se em torno de 120 dias, período este que deve ser tomado como referência para o planejamento da irrigação. A eficiência de uso da água para os solos de textura leve apresentou valores médios de 0,2 kg.m-3; já para os solos de textura pesada, de 0,43 kg.m-3. A eficiência de aplicação de água na unidade textural argilo-siltosa, solo adequado ao cultivo de arroz apresentou um valor médio de 66%. Na unidade textural areia franca, porém, solo sem aptidão ao cultivo do arroz, a eficiência de aplicação foi apenas de 35%, considerando-se em ambos os casos, somente os eventos de irrigação sem déficit. A rentabilidade líquida de cada mil m3 , utilizando a metodologia de cobrança de água derivada e aplicada, mostrou-se superior nos solos argilo-siltosos com valores entre R$ 179,0 e R$ 94,0, enquanto os solos de textura mais leve esta rentabilidade não ultrapassou os R$ 58,0. A receita líquida obtida em 1,0 ha de arroz na unidade textural areia franca (R$1.900,00), comparativamente ao valor obtido na unidade textural argilo-siltosa (R$2.400,00), incentiva o cultivo de arroz em solos sem aptidão para a cultura, porquanto o sistema de cobrança de água atualmente em vigor, leva em consideração a área irrigada e não o volume de água aplicada. A análise da rentabilidade nas unidades texturais areia franca e argilo-siltosa, demonstrou a viabilidade do cultivo do arroz para ambas as unidades, em base aos critérios convencionais da análise de investimento, porém, simulando-se uma remuneração mensal do produtor no valor de R$ 240,0, o plano de cultivo na unidade textural areia-franca é inviável, conforme os resultados obtidos: relação benefício custo (B/C) 0,98; valor presente líquido (VPL) -603,9 e taxa interna de retorno (TIR) 3,5%. Na unidade textural argilo-siltosa, porém, os indicadores se mostraram viáveis: B/C 1,145, VPL R$ 4.204,1 e TIR 60,33%.