Water is characterised by both its quantity (availability) and its quality. Salinity, which is one of the major water quality parameters limiting use of a wide range of land and water resources, refers to the total dissolved solutes in water. It is influenced by a combination of several soil-water-salt-plant related processes. In order to develop optimum management schemes for environmental control through relevant hydrological modelling techniques, it is important to identify and understand these processes affecting salinity. Therefore, the various sources and processes controlling salt release and transport from the soil surface through the root zone to groundwater and streams as well as reservoirs are extensively reviewed in this project with subsequent exploration of some hydro salinity modelling approaches. The simulation of large and complex hydrological systems, such as these at a catchment scale, requires a flexible and efficient modelling tool to assist in the assessment of the impact of land and water use alternatives on the salt balance. The currently available catchment models offer varying degrees of suitability with respect to modelling hydrological problems, dependent on the model structure and the type of the approach used. The A CR U agrohydrological modelling system, with its physically-conceptually based characteristics as well as being a multi-purpose model that is able to operate both as a lumped and distributed model, was found to be suitable for hydro salinity modelling at a catchment scale through the incorporation of an appropriate hydro salinity module. The main aim of this project was to develop, validate and verify a hydro salinity module for the ACRU model. This module is developed in the object-oriented version of ACRU, viz. ACRU2000, and it inherits the basic structure and objects of the model. The module involves the interaction of the hydrological processes represented in ACRU and salinity related processes. Hence, it is designated as ACRUSalinity. In general, the module is developed through extensive review of ACRU and hydrosalinity models, followed by conceptualisation and design of objects in the module. It is then written in Java object-oriented programming language. The development of ACRUSalinity is based mainly on the interaction between three objects, viz. Components, Data and Processes. Component objects in ACRU2000 represent the physical features in the hydrological system being modelled. Data objects are mainly used to store data or information. The Process objects describe processes that can take place in a conceptual or real world hydrological system. The Process objects in ACRUSalinity are grouped into six packages that conduct: • the initial salt load determination in subsurface components and a reservoir • determination of wet atmospheric deposition and salt input from irrigation water • subsurface salt balance, salt generation and salt movement • surface flow salt balance and salt movement • reservoir salt budgeting and salt routing and • channel-reach salt balancing and, in the case of distributed hydro salinity modelling, salt transfer between sub-catchments. The second aim of the project was the validation and verification of the module. Code validation was undertaken through mass balance computations while verification of the module was through comparison of simulated streamflow salinity against observed values as recorded at gauging weir UIH005 which drains the Upper Mkomazi Catchment in KwaZuluNatal, South Africa. Results from a graphical and statistical analysis of observed and simulated values have shown that the simulated streamflow salinity values mimic the observed values remarkably well. As part of the module development and validation, sensitivity analysis of the major input parameters of ACRUSalinity was also conducted. This is then followed by a case study that demonstrates some potential applications of the module. In general, results from the module evaluation have indicated that ACRUSalinity can be used to provide a reasonable first order approximation in various hydrosalinity studies. Most of the major sources and controlling factors of salinity are accommodated in the ACRUSalinity module which was developed in this project. However, for a more accurate and a better performance of the module in diversified catchments, further research needs to be conducted to account for the impact of salt loading from certain sources and to derive the value of some input parameters to the new module. The research needs include incorporation in the module of the impact of salt loading from fertilizer applications as well as from urban and industrial effluents. Similarly, further research needs to be undertaken to facilitate the module's conducting salt routing at sub-daily time step and to account for the impact of bypass flows in heavy soils on the surface and subsurface salt balances. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.

Lucerne is a deep-rooted perennial pasture that is promoted to land managers in southern Australia to mitigate the effects of dryland salinity, a problem of national significance caused by the replacement of native trees and shrubs with annual crops and pastures. In recent years, the acceptance of climate change has provided further rationale for increasing the use of perennial legumes in our farming systems. Perennial legumes have a role in offsetting C02 emissions by sequestering C and N in soil, and provide new, resilient options for future farming in a warmer and more variable climate. This research has focused on evaluating the diverse range of germplasm found in lucerne (Medicago sativa spp.) for a range of attributes in order to determine its compatibility with existing and future farming systems in southern Australia. Regional field evaluation at 8 sites in southern Australia showed that lucerne is a broadly adapted and robust plant. After 3 years, plant density ranged from 2-55 plants / m2 with differences in persistence attributed to tolerance to a combination of stresses including soil acidity, saline and sodic subsoils, drought conditions and persistent heavy grazing. Highly winter-active lucerne (class 9-10) was confirmed to be the most suitable group for short phase rotations in southern Australia, providing grazing is well managed. This germplasm was less persistent than other winter activity groups, but produces more total herbage yield in environments with winter dominant rainfall patterns. Highly winter-active lucerne has poor persistence under continuous grazing, but this may aid in its removal when used in rotation with crops. Winteractive germplasm (class 6-8) was more grazing tolerant and persistent, making it the most suitable group for longer phase rotations (>4 years), or where more flexible grazing management practices are required (i.e. 35 days grazing followed by 35 days recovery). Individual grazing tolerant plants from this group were selected and randomly inter-mated to form new breeder’s lines in the development of a grazing tolerant cultivar. For the first time, the high water-use of a farming system involving wheat overcropped into lucerne is presented. Lucerne over-cropped with wheat used an additional 43-88 mm of water in comparison to continuous wheat at Roseworthy and Katanning respectively. Over-cropping reduced wheat yield by 13-63%, but it can be more efficient in terms of land area to grow lucerne and wheat as a mixture than on separate parcels of land. Very winter-dormant lucerne (class 1-2) appears to be less competitive with winter cereal crops during wheat establishment. It may also be possible to reduce lucerne’s competition with wheat at the critical stage of anthesis, with low spring yielding lucerne varieties identified in this research (SA37908). This group of plants provides excellent potential for the development of high water-use farming systems because they are grazing tolerant and persistent, and have summer forage production and sub-soil water extraction rates that are equivalent to winter active lucerne. The research has been used to identify the perfect ideotype for lucerne in phase farming and over-cropping systems, which can be used to set targets in future breeding programs. The research also highlights current opportunities for the integration of lucerne into southern Australian farming systems to help curb the spread of dryland salinity and reduce the impact of climate change. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1344608 / Thesis (Ph.D.) - University of Adelaide, School of Agriculture, Food and Wine, 2008

Thesis (Ph.D.)--Flinders University, School of Biological Sciences. / Typescript bound. Includes bibliographical references. Also available online.

Thesis (MSc)--University of Stellenbosch, 2005. / Bibliography. Also available via the Internet.

O reúso de efluentes de esgotos domésticos na irrigação de culturas representa uma alternativa adequada na gestão dos recursos hídricos devido ao fornecimento de nutrientes e água em quantidades suficientes para o desenvolvimento das culturas, porém, também pode introduz impactos negativos ao solo, em parte, potencializados pela irrigação contínua ao longo do tempo. O maior efeito está relacionado com o aumento da salinidade e sodicidade. Uma alternativa para mitigar este impacto, é o uso de espécies vegetais extratoras e acumuladoras de sais que estão presentes no solo. Neste trabalho avaliaram-se as alterações nas propriedades químicas de um planossolo (disposto em 36 vasos, 18 isolados da chuva e dos ventos e 18 expostos a eventos climáticos) irrigado durante dois meses (junho-julho) com efluente de esgoto tratado por um reator UASB + lagoa de polimento. Posteriormente, avaliou-se o desempenho da espécie halófita Atriplex nummularia na remoção de sais e cátions acumulados no substrato (agosto 2008 – fevereiro 2009), monitorando o comportamento da condutividade elétrica, sódio, potássio, cálcio, magnésio e pH (no extrato do solo) e pH, condutividade elétrica e sódio trocável no percolado dos vasos. Durante a fitorremediação, foram aplicados além do efluente utilizado na etapa anterior (tratamento 3), efluente de um sistema UASB (tratamento 2) e água potável (tratamento 1). Também foi avaliado o comportamento das características físicas do solo mediante a determinação das curvas de retenção de água no inicio e final do experimento. A irrigação com o efluente do sistema UASB + lagoa de polimento incrementou significativamente o teor de sódio ao mesmo tempo em que diminuiu as concentrações de cálcio e magnésio; incrementando em até 30 % o percentual de sódio trocável (PST), indicando a sodificação da camada superficial (0-20 cm) dos substratos. O pH e a condutividade elétrica (indicadores da salinidade do solo quando atingem valores inferiores a 8,5 e superiores a 4 dS m-1, respectivamente) aumentaram sem atingir valores críticos. As condições de maior acumulação de sais e cátions apresentaram-se nos vasos que não estiveram expostos às variáveis climáticas. Com respeito à etapa de fitorremediação, as eficiências na remoção de sódio estiveram acima de 85% (em ausência de chuva) e fora da estufa valores entre 30 – 45% para os tratamentos 2 e 3 e acima de 80% para o tratamento 1. Resultados que mostram o melhor desenvolvimento da planta na ausência de chuvas e ventos fortes. Já os efeitos sobre as características físicas das amostras não foram estatisticamente significativos (α = 0.01), provavelmente pelo curto tempo de duração do experimento. Os resultados em geral, evidenciaram o potencial da Atriplex nummularia na fitorremediação de solos irrigados com efluentes de esgotos tratados. / Wastewater reuse in crops irrigation represents a good alternative in the water resources management because it supplies nutrients and water in sufficient amount to guarantee the growing of cultures, but also can affects negatively the soil due to the constant irrigation along time. The worst effect is related to the increase of the soil salinity and sodium content. An option to mitigate this effect is to use varieties of vegetable species that can extract or accumulate salt. This study researched the changes in the chemical properties of a Plano soil (distributed in 36 pots, 18 protected of rains and winds and 18 exposed them), irrigated over two months (June – July) with secondary treated wastewater from an anaerobic reactor/maturation pond. Besides that, it was studied the performance of the halophyte Atriplex nummularia in removing salts and cations accumulated in the soil (August 2008 – February 2009), by measuring from the soil extract samples: the behavior of electrical conductivity, sodium, potassium, calcium, magnesium and pH; and from the pots leachate: pH, electrical conductivity and exchangeable sodium. During the phytoremediation process, besides the wastewater effluent used in the first stage (treatment 3), there were also applied wastewater effluent from an UASB reactor (treatment 2) and potable water (treatment 1). Also, it was studied the behavior of soil´s physicals characteristic measuring water retention curves at the beginning and end of the experiment. Irrigation with the secondary treated wastewater from an anaerobic reactor/maturation pond increased significantly soil’s sodium concentration, and simultaneously, it decreased calcium and magnesium concentrations in the soil; augmenting the Exchangeable Sodium Percentages (ESP), thus indicating the sodification of soil superficial layer (0 – 20 cm). The values of pH and electrical conductivity (soil salinity indicators when reaching values below 8,5 and over 4 dS m-1, respectively) increased, but did not reached critical values. The pots not exposed to environmental conditions presented greater salts and cations concentrations accumulated on top soil. Phytoremediation stage efficiencies were higher than 85% (in the absence of rain) and between 30 and 45% (in the presence of rain) for applied treatments 2 and 3, respectively; and more than 80% for the applied treatment 1. These results showed that the plant performance is better in the absence of rain and strong winds. The changes on the physical characteristics were statistically non-significant (α = 0.01), probably because of the short duration of the experiment. The results in general, showed the potential of the Atriplex nummularia in phytoremediation processes of wastewater-irrigated soils.

Made available in DSpace on 2014-06-11T19:26:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-05-11Bitstream added on 2014-06-13T20:34:06Z : No. of bitstreams: 1 yamasaki_mt_me_bauru.pdf: 2126849 bytes, checksum: 4896e264bafeff1d70577b538318f03e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A resistividade elétrica vem sendo somada junto aos estudos de investigação geotécnica devido ao seu apelo ambiental, visto que esta técnica se dá por meio da imposição de um fluxo de corrente elétrica em uma amostra de solo, permitindo-se avaliar as condições geológicas locais por um método não destrutivo. A obtenção dessa medida vem sendo somada aos estudos de investigação geotécnica devido ao seu apelo ambiental, otimizando as amostragens e permitindo a avaliação das condições geológicas locais por meio de um método não destrutivo. Dessa maneira, o objetivo dessa dissertação de mestrado é avaliar, em laboratório, o comportamento da resistividade elétrica variando-se o teor de salinidade no fluido de percolação em dois solos tropicais: um arenoso, sedimentar, característico da região de Bauru, e outro argiloso, resultado do intemperismo do Diabásio, proveniente do município de Piracicaba. As análises foram realizadas utilizando-se resultados, dos ensaios de caracterização, compactação, permeabilidade e curva de retenção. o teor de salinidade do fluido foi considerado, tanto na compactação, como na percolação em três concentrações: água destilada, 250 ppm e 500 ppm de NaCI, além de abastecimento, controlando-se o teor de umidade, a compactação, o índice de vazios e o grau de saturação. Os resultados mostraram-se que a resistividade elétrica tende a ser constante no ramo úmido da curva de compactação e também quando o grau de saturação está acima de 80%. Notou-se também que a curva de resistividade versus sucção pode ser divida em dois trechos: o primeiro corresponde às baixas sucções, com a continuidade da água nos poros e resistividade menores; o segundo trecho, que se inicia na primeira entrada de dar, conduz a um nítido aumento nos valores de... / The electrical resitivity of a homogeneous material could be defined as the measurements of the difficult of crossing of the electrical current and it depends of the dimension and type of material. However, when that material is soil, composed by three phases (solid, liquid and gas), this measure is influenced by several factors that could be controlled in laboratory tests. The electrical resistivity has been used geotechnical research studies since this technique improve the sampling of environmental works and allowing the evaluation of local geological conditions through a non-destructive method. Thus, the goal of the study was evaluate the behavior of electrical resistivity of two tropical soils varying the salinity concentration in the percolation fluid: a sandy sediment, characteristic of the Bauru city; a clayey soil, Weathered of Diabase from Piracicaba City. Results of soil mechanics laboratory tests as characterization tests, compaction, permeability and soil-water retention curve were used in the analyses. In both, compaction and permeability tests, the procedure were carried out varying the fluid salinity: distilled water, water supply; 250ppm and 500ppm of NaCi. The moisture content, compaction energy, void ratio and degree of saturation. The tests results showed the rsistivity values tend to be constant in the wet density curve and when the degree of saturation is above 80%. It was also noted that the curve of resistivity suction could be divided into two segments: the first corresponds to low suctions where there is continuity of water in the porous leading to low resistivity values; the second segment begins in the first air entrance, with discountinuous state of pore-water and sa sharphy increase in the resistivity values. The formation factors (FF) were obtained during the permeability tests: 7,5 to the sandy soil and... (Complete abstract click electronic access below)

O reúso de efluentes de esgotos domésticos na irrigação de culturas representa uma alternativa adequada na gestão dos recursos hídricos devido ao fornecimento de nutrientes e água em quantidades suficientes para o desenvolvimento das culturas, porém, também pode introduz impactos negativos ao solo, em parte, potencializados pela irrigação contínua ao longo do tempo. O maior efeito está relacionado com o aumento da salinidade e sodicidade. Uma alternativa para mitigar este impacto, é o uso de espécies vegetais extratoras e acumuladoras de sais que estão presentes no solo. Neste trabalho avaliaram-se as alterações nas propriedades químicas de um planossolo (disposto em 36 vasos, 18 isolados da chuva e dos ventos e 18 expostos a eventos climáticos) irrigado durante dois meses (junho-julho) com efluente de esgoto tratado por um reator UASB + lagoa de polimento. Posteriormente, avaliou-se o desempenho da espécie halófita Atriplex nummularia na remoção de sais e cátions acumulados no substrato (agosto 2008 – fevereiro 2009), monitorando o comportamento da condutividade elétrica, sódio, potássio, cálcio, magnésio e pH (no extrato do solo) e pH, condutividade elétrica e sódio trocável no percolado dos vasos. Durante a fitorremediação, foram aplicados além do efluente utilizado na etapa anterior (tratamento 3), efluente de um sistema UASB (tratamento 2) e água potável (tratamento 1). Também foi avaliado o comportamento das características físicas do solo mediante a determinação das curvas de retenção de água no inicio e final do experimento. A irrigação com o efluente do sistema UASB + lagoa de polimento incrementou significativamente o teor de sódio ao mesmo tempo em que diminuiu as concentrações de cálcio e magnésio; incrementando em até 30 % o percentual de sódio trocável (PST), indicando a sodificação da camada superficial (0-20 cm) dos substratos. O pH e a condutividade elétrica (indicadores da salinidade do solo quando atingem valores inferiores a 8,5 e superiores a 4 dS m-1, respectivamente) aumentaram sem atingir valores críticos. As condições de maior acumulação de sais e cátions apresentaram-se nos vasos que não estiveram expostos às variáveis climáticas. Com respeito à etapa de fitorremediação, as eficiências na remoção de sódio estiveram acima de 85% (em ausência de chuva) e fora da estufa valores entre 30 – 45% para os tratamentos 2 e 3 e acima de 80% para o tratamento 1. Resultados que mostram o melhor desenvolvimento da planta na ausência de chuvas e ventos fortes. Já os efeitos sobre as características físicas das amostras não foram estatisticamente significativos (α = 0.01), provavelmente pelo curto tempo de duração do experimento. Os resultados em geral, evidenciaram o potencial da Atriplex nummularia na fitorremediação de solos irrigados com efluentes de esgotos tratados. / Wastewater reuse in crops irrigation represents a good alternative in the water resources management because it supplies nutrients and water in sufficient amount to guarantee the growing of cultures, but also can affects negatively the soil due to the constant irrigation along time. The worst effect is related to the increase of the soil salinity and sodium content. An option to mitigate this effect is to use varieties of vegetable species that can extract or accumulate salt. This study researched the changes in the chemical properties of a Plano soil (distributed in 36 pots, 18 protected of rains and winds and 18 exposed them), irrigated over two months (June – July) with secondary treated wastewater from an anaerobic reactor/maturation pond. Besides that, it was studied the performance of the halophyte Atriplex nummularia in removing salts and cations accumulated in the soil (August 2008 – February 2009), by measuring from the soil extract samples: the behavior of electrical conductivity, sodium, potassium, calcium, magnesium and pH; and from the pots leachate: pH, electrical conductivity and exchangeable sodium. During the phytoremediation process, besides the wastewater effluent used in the first stage (treatment 3), there were also applied wastewater effluent from an UASB reactor (treatment 2) and potable water (treatment 1). Also, it was studied the behavior of soil´s physicals characteristic measuring water retention curves at the beginning and end of the experiment. Irrigation with the secondary treated wastewater from an anaerobic reactor/maturation pond increased significantly soil’s sodium concentration, and simultaneously, it decreased calcium and magnesium concentrations in the soil; augmenting the Exchangeable Sodium Percentages (ESP), thus indicating the sodification of soil superficial layer (0 – 20 cm). The values of pH and electrical conductivity (soil salinity indicators when reaching values below 8,5 and over 4 dS m-1, respectively) increased, but did not reached critical values. The pots not exposed to environmental conditions presented greater salts and cations concentrations accumulated on top soil. Phytoremediation stage efficiencies were higher than 85% (in the absence of rain) and between 30 and 45% (in the presence of rain) for applied treatments 2 and 3, respectively; and more than 80% for the applied treatment 1. These results showed that the plant performance is better in the absence of rain and strong winds. The changes on the physical characteristics were statistically non-significant (α = 0.01), probably because of the short duration of the experiment. The results in general, showed the potential of the Atriplex nummularia in phytoremediation processes of wastewater-irrigated soils.

Made available in DSpace on 2016-06-02T18:55:24Z (GMT). No. of bitstreams: 1 4855.pdf: 1701786 bytes, checksum: f886dd37262de3e99d2829c84764b9bf (MD5) Previous issue date: 2013-02-01 / Universidade Federal de Minas Gerais / The concern in developing strategies to solve the water scarcity problem is growing and actual. As a big consumer of the available fresh water, agriculture is the activity with the biggest potential for applying of water reuse. This study set up in CCA/UFSCar evaluated, on laboratory conditions, the physical and chemical properties of a soil irrigated with treated wastewater after the application of a water sheet corresponding to five cycles of lettuce s growth (Lactuca sativa, L.) and in a greenhouse, evaluated the sanitary characteristics and mass of the Elisa type lettuce and the physical, chemical and microbiological characteristics of the soil after the cultivation with treated wastewater, comes from the wastewater treatment plant from the university. In the laboratory experiment, eighteen undisturbed soil samples were coupled in a constant head permeameter and received a water sheet corresponding to five cycles of lettuce s growth, 0.58, 1.16, 1.74, 2.32 and 2.9 L of water for each cycle. The soil samples were distributed in five groups that received treated wastewater and one control group that received distilled water. Soil samples were collected to analyze the granulometry, saturated hydraulic conductivity (ksat), exchangeable sodium percentage (ESP) and soil fertility. Treated wastewater and distilled water leached samples were collected to analyze the electrical conductivity, sodium adsorption ratio (SAR), turbidity, pH, sodium, potassium, magnesium, phosphorus, calcium and nitrate. In a greenhouse, two cycles of Elisa lettuce were cultivated with two treatments (treated wastewater and supply water) with four repetitions. After the harvest of the lettuce, soil samples were collected to analyze granulometry, density, ksat, and soil fertility, total coliforms, Escherichia coli and heterotrophic. The harvested lettuces were analyzed for total coliforms, Escherichia coli and chemical analysis of plant tissue. In laboratory, there was an increase of ESP and the concentration of phosphorus and sodium on soil after the application of the water sheet. There wasn t significant difference on the physical properties of soil, turbidity and SAR. In a greenhouse, there wasn t significant difference between the treatments on nutrients absorption of lettuces cultivated, but the weight of lettuces irrigated with wastewater was 100% greater than the lettuces irrigated with supply water on the second cycle. It was not detected the presence of Esherichia coli on the cultivated lettuces, but there was total coliforms contamination, that presents a risk of contamination to the consumer. The irrigation with treated wastewater increased the nutrients on soil and the SAR indicated a soil salinization risk. The treated wastewater does not cause damage on the physical properties of soil. / A preocupação em desenvolver estratégias para minimizar o problema da escassez de água é crescente e atual. Como grande consumidora da água doce disponível, a agricultura é o setor com maior potencial de aplicação da água de reúso. Este trabalho desenvolvido no CCA/UFSCar avaliou, em laboratório, as propriedades físicas e químicas do solo irrigado com água de reúso tratada após aplicação de lâmina de irrigação correspondente ao cultivo de cinco ciclos de alface (Lactuca sativa L.) e, em casa de vegetação, as características sanitárias e a massa da cultura de alface Elisa e as características físicas, químicas e microbiológicas do solo após o cultivo com água de reúso, proveniente da estação de tratamento de esgoto da universidade. No experimento em laboratório, dezoito amostras indeformadas de solo foram acopladas em permeâmetro de carga constante e receberam lâmina de irrigação referente a cinco ciclos de cultivo de alface, 0,58, 1,16, 1,74, 2,32 e 2,9 L de água para cada ciclo. As amostras foram divididas em cinco grupos que receberam água de reúso e um grupo controle, que recebeu água destilada. Amostras de solo foram coletadas para determinar a granulometria, condutividade hidráulica saturada (ksat), porcentagem de sódio trocável (PST) e fertilidade do solo. Amostras da água de reúso e água destilada lixiviadas foram coletadas para determinar a condutividade elétrica, razão de adsorção de sódio (RAS), turbidez, pH, sódio, potássio, magnésio, fósforo, cálcio e nitrato. Em casa de vegetação, dois ciclos de alface "Elisa" foram cultivados com dois tratamentos (água de reúso e de abastecimento) com quatro repetições. Após a colheita, amostras de solo foram coletadas para determinar a granulometria, densidade, ksat, fertilidade do solo, coliformes totais, Escherichia coli e heterotróficos. Nas alfaces colhidas foram determinados os coliformes totais, Escherichia coli e análise química do tecido vegetal. Em laboratório, houve aumento da PST e teor de fósforo e sódio no solo após aplicação das lâminas de irrigação. Não houve diferença significativa nas propriedades físicas do solo, turbidez e RAS. Na casa de vegetação, não houve diferença significativa entre os tratamentos na absorção de nutrientes pelas alfaces cultivadas, porém, a massa das alfaces irrigadas com água de reúso foi 100% maior que a das alfaces irrigadas com água de abastecimento no segundo ciclo. Não foi detectada presença de Escherichia coli nas alfaces cultivadas, mas houve concentração de coliformes totais, o que representa risco de contaminação ao consumidor. A irrigação com água de reúso aumentou o teor de nutrientes no solo e a RAS indicou risco de salinização. A água de reúso não causou alterações nas propriedades físicas do solo.

Made available in DSpace on 2015-05-14T12:17:11Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3692529 bytes, checksum: 617960435734547cdb52750a2e656349 (MD5) Previous issue date: 2013-08-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Salinization appears as one of the main present problems in semiarid irrigated areas of the Northeast Region, leading to environmental and economic losses. This study consisted of a degradation analysis of natural resources and the impacts brought up by inadequate soil use in the São Gonçalo Irrigated Perimeter. In order to analyze this problem, the following methodological procedures were carried out: map elaboration for soil use; field research with collection samples of water (6 samples), and of soil (157 samples) for a laboratorial analysis, and questionnaires in a universe of 100 colonists for a secondary data collection. Results found showed that: the Perimeter is, mostly, made up of soils with a great salinization tendency; many pieces of land are cultivated with well-water with high concentrations of salt in solution; the flooding irrigation method is one of the irrigation types used, also contributing for local salinization: plantations with the most remarkable PISG production are of a vegetal type which have high productive levels even in salinization (coconut and rice); many spaces are abandoned or utilized for cattle-raising because they do not offer any agricultural productivity conditions any longer; most of the irrigators have salinization problems in their allotments; 51,78% of the PISG territory have high salinity levels, making it difficult for agriculture to develop with species that are not adapted to such conditions; a considerable part of the irrigators appear to be unaware of what motivates the problem of salinization and do not know the fact that the irrigation methods and the water utilized creates or intensifies this process; most of the irrigators do not have technical maintenance, making the cultivation without the technical knowledge demanded by irrigated agriculture; there is great dissatisfaction by the irrigators towards the present situation of the Perimeter s infrastructure, and problems about roads and the occurrences of obstructions in drainage and irrigation channels were the main complaints. Based on what was observed, we believe that, although benefits able to be obtained by the use of irrigated agriculture are incontestable, it is also undeniable that they may bring remarkable impacts over the environment. Taking into account that the reality observed in PISG is part of many of the perimeters irrigated in the Brazilian semiarid, a sense of reflection over these areas as well as the present activity arouse. / A salinização constitui-se em um dos principais problemas existentes nas áreas irrigadas do semiárido nordestino, provocando danos econômicos e ambientais. Este trabalho consistiu em uma análise da degradação dos recursos naturais e os impactos gerados pelo manejo inadequado do solo no Perímetro Irrigado de São Gonçalo. Para analisar esta problemática, foram tomados os seguintes procedimentos metodológicos: elaboração de mapa de uso do solo; pesquisas de campo, com a coleta de amostras de água (6 amostras) e de solo (157 amostras) para posterior análise em laboratório, e aplicação de questionários em um universo de 100 colonos para coleta de dados secundários. Os resultados encontrados mostraram que: o Perímetro é composto em grande parte do seu território por solos com grande tendência a salinização; muitos lotes são cultivados com a utilização de água de poços com altos teores de sais em solução; o método de irrigação por inundação é uma das formas de irrigação utilizadas, também contribuindo para a salinização local; os plantios que possuem maior destaque na produção do PISG são de espécies vegetais que obtém bons níveis produtivos, mesmo em situação de salinidade (coco e arroz); muitos espaços são abandonados ou utilizados para a pecuária por não apresentarem mais condições de produtividade agrícola; a maior parte dos irrigantes possuem problemas de salinização em seus lotes; 51,78% do território do PISG possui teores elevados de sais, dificultando o desenvolvimento da agricultura com espécies não adaptadas a estas condições; uma parte bastante considerável dos irrigantes não sabe o que motiva o problema da salinização, não tendo o conhecimento que os métodos de irrigação e a água utilizada criam ou intensificam esse processo; a maior parte dos irrigantes não possui assistência técnica, exercendo o cultivo sem os conhecimentos técnicos que a agricultura irrigada exige; ocorre grande insatisfação dos irrigantes para com a atual situação da infraestrutura do Perímetro, tendo como principais queixas problemas referentes às estradas e a ocorrência de obstrução dos drenos e dos canais de irrigação. Com base no que foi observado, acreditamos que apesar de serem incontestáveis os benefícios capazes de serem obtidos pelo uso da agricultura irrigada, não se pode negar também que estes podem gerar impactos notáveis ao ambiente. Levando em consideração que a realidade observada no PISG faz parte de muitos dos perímetros irrigados no semiárido brasileiro, urge um repensar sobre essas áreas, assim como a própria atividade em questão.

Orientador: Anna Silvia Palcheco Peixoto / Banca: Vagner Roberto Elis / Banca: George de Paula Bernardes / Resumo: A resistividade elétrica vem sendo somada junto aos estudos de investigação geotécnica devido ao seu apelo ambiental, visto que esta técnica se dá por meio da imposição de um fluxo de corrente elétrica em uma amostra de solo, permitindo-se avaliar as condições geológicas locais por um método não destrutivo. A obtenção dessa medida vem sendo somada aos estudos de investigação geotécnica devido ao seu apelo ambiental, otimizando as amostragens e permitindo a avaliação das condições geológicas locais por meio de um método não destrutivo. Dessa maneira, o objetivo dessa dissertação de mestrado é avaliar, em laboratório, o comportamento da resistividade elétrica variando-se o teor de salinidade no fluido de percolação em dois solos tropicais: um arenoso, sedimentar, característico da região de Bauru, e outro argiloso, resultado do intemperismo do Diabásio, proveniente do município de Piracicaba. As análises foram realizadas utilizando-se resultados, dos ensaios de caracterização, compactação, permeabilidade e curva de retenção. o teor de salinidade do fluido foi considerado, tanto na compactação, como na percolação em três concentrações: água destilada, 250 ppm e 500 ppm de NaCI, além de abastecimento, controlando-se o teor de umidade, a compactação, o índice de vazios e o grau de saturação. Os resultados mostraram-se que a resistividade elétrica tende a ser constante no ramo úmido da curva de compactação e também quando o grau de saturação está acima de 80%. Notou-se também que a curva de resistividade versus sucção pode ser divida em dois trechos: o primeiro corresponde às baixas sucções, com a continuidade da água nos poros e resistividade menores; o segundo trecho, que se inicia na primeira entrada de dar, conduz a um nítido aumento nos valores de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The electrical resitivity of a homogeneous material could be defined as the measurements of the difficult of crossing of the electrical current and it depends of the dimension and type of material. However, when that material is soil, composed by three phases (solid, liquid and gas), this measure is influenced by several factors that could be controlled in laboratory tests. The electrical resistivity has been used geotechnical research studies since this technique improve the sampling of environmental works and allowing the evaluation of local geological conditions through a non-destructive method. Thus, the goal of the study was evaluate the behavior of electrical resistivity of two tropical soils varying the salinity concentration in the percolation fluid: a sandy sediment, characteristic of the Bauru city; a clayey soil, Weathered of Diabase from Piracicaba City. Results of soil mechanics laboratory tests as characterization tests, compaction, permeability and soil-water retention curve were used in the analyses. In both, compaction and permeability tests, the procedure were carried out varying the fluid salinity: distilled water, water supply; 250ppm and 500ppm of NaCi. The moisture content, compaction energy, void ratio and degree of saturation. The tests results showed the rsistivity values tend to be constant in the wet density curve and when the degree of saturation is above 80%. It was also noted that the curve of resistivity suction could be divided into two segments: the first corresponds to low suctions where there is continuity of water in the porous leading to low resistivity values; the second segment begins in the first air entrance, with discountinuous state of pore-water and sa sharphy increase in the resistivity values. The formation factors (FF) were obtained during the permeability tests: 7,5 to the sandy soil and... (Complete abstract click electronic access below) / Mestre