Apesar da grande área ocupada pelo Cerrado no território brasileiro e de sua importância ecológica e hidrológica, ainda é desconhecida a repartição da água das chuvas no gradiente fisionômico da vegetação nesse bioma. No presente estudo quantificamos a interceptação da água das chuvas e a umidade do solo, para estabelecer correlações entre as características estruturais da vegetação, representadas principalmente pela área basal, e os dados hidrológicos. Para tanto, quantificamos a transprecipitação e o escoamento pelo tronco das árvores, em 15 parcelas representativas do gradiente fisionômico entre o cerrado típico e o cerradão, localizados na Estação Ecológica de Assis (EEcA), SP, para obtenção da proporção da precipitação efetiva que atravessa o dossel e chega à superfície do solo, em comparação com a precipitação total, quantificada a céu aberto. Os indivíduos lenhosos em cada parcela com DAP 5 cm foram identificados e medidos. A quantidade de transprecipitação foi tanto maior quanto menos complexa a estrutura da vegetação, sendo também influenciada pelas características da chuva incidente. A proporção da transprecipitação também foi fortemente influenciada pela estrutura da vegetação, porém, não foi detectada influência das características das chuvas. Assim, foi possível concluir que, em ambiente de Cerrado, é a estrutura da vegetação que influencia de forma decisiva a proporção de água que alcançará o solo sob forma difusa. A facilidade em captar a água da chuva e escoá-la pelo tronco variou em função de atributos da árvore, sendo que árvores mais altas e com copa volumosa escoaram maior quantidade, enquanto árvores de crescimento monopodial, tronco ereto e reto e copa compacta têm maior eficiência de captação. O agrupamento das parcelas em diferentes fisionomias resultou em diferenças significativas nas taxas de precipitação efetiva e interceptação, indicando que elas devem ser caracterizadas hidrologicamente como ambientes distintos, onde há gradação na quantidade de água que chega ao solo em função do gradiente de biomassa. A transição da entrada de água ao solo no gradiente do Cerrrado é crescente e contínua, desde as comunidades menos densas (cerrado típico) até as comunidades mais densas (cerradão). A dinâmica e a disponibilidade de água do solo foram mais influenciadas pelas propriedades do solo do que pela cobertura vegetal, quando ambos os fatores são variáveis. Concluímos que, em regiões nas quais a água é um recurso escasso, o manejo visando controlar a biomassa da vegetação é um recurso válido, visto que os resultados apontam para a importância das fisionomias mais abertas do Cerrado para a produção hídrica. / Despite the large area occupied by the Cerrado in Brazil and its ecological and hydrological importance, the rainfall partioning in the physiognomy gradient of the vegetation in this biome is still to be ellucidated. In this study, we quantified rainfall interception and the of soil moisture to establish correlations between vegetation structure, represented by the basal area, and hydrological data. Therefore, we quantified the troughfall and stemflow of trees in 15 plots representing the physiognomic gradient between typical cerradão and cerradão, located at Assis Ecological Station (EEcA), SP, to obtain the net rainfall reaching the ground, compared to the total precipitation quantified at open adjacent area. The woody plants with DBH 5 cm were identified and measured in every plot. Troughfall was lower when the vegetation structure was more complex, and was not influenced by micrometeorological factors. We concluded that, in Cerrado, vegetation structure decisively influences the proportion of rainfall to reaching the soil. The stemflow amount was greater the larger the tree and the tree canopy, while trees with monopodial growing, erect and straight trunk and compact canopy had more capture efficiency. Grouping plots by Cerrado physiognomies resulted in significant differences in both net precipitation and interception, indicating that they must be categorizes as hydrologically distinct environments. There is increasing and continuous transition from the more open communities (cerrado típico) to the forest physiognomies (cerradão) in the proportion of rainfall retained by the canopies. The dynamics and the availability of soil water were more influenced by soil properties than the vegetation cover, when both factors varies. This study points out the importance of low biomassa Cerrado physiognomies for hydric production and we concluded that, when and where water is a scarce resource, controlling vegetation biomass can be recommended to aiming at water production.

Neste trabalho, o método de extração em fase sólida (SPE) com análises por cromatografia gasosa acoplada à espectrometria de massas (GC-MS) foi desenvolvido para a determinação de levoglucosano em amostras de água de chuva da região de Ribeirão Preto-SP, Brasil. O monossacarídeo levoglucosano foi proposto como um marcador específico para queima de biomassa, uma vez que o mesmo é liberado durante a pirólise da celulose em temperaturas acima de 300ºC. Após a otimização das variáveis SPE, as melhores condições dentre as avaliadas foram as seguintes: cartuchos SPE recheados com a fase extratora quitosana (1,0 g), volume de amostra igual a 5,0 mL, vazão de 1,0 mL min-1, solvente de eluição: metanol (volume igual a 2,5 mL), sem a adição de sal. O método SPE/GC-MS para a determinação de levoglucosano em amostras de chuva apresentou faixa linear no intervalo de concentração de 0,05 µg mL-1 a 0,50 µg mL-1, r 0,9967, exatidão de 95 a 110% e precisão inter ensaios com coeficientes de variação (CV) menores que 15%, exceto para o limite de quantificação (0,05 µg mL-1) o qual apresentou CV inferior a 20%. Segundo as determinações (SPE/GC-MS) de levoglucosano em amostras de água de chuva coletadas no período 03/08/2011 à 09/04/2012, as concentrações médias de levoglucosano na safra de cana-de-açúcar são aproximadamente quatro vezes superior ao período de entressafra. Este fato é justificado pela elevada taxa de queima da palha da cana-de-açúcar na região de Ribeirão Preto-SP no período safra, e consequentemente, maior emissão de material particulado para a atmosfera incluindo levoglucosano, COD, entre outros. / In this work, the method of solid phase extraction (SPE) with gas chromatography - mass spectrometry (GC-MS) analysis was developed for the determination of levoglucosan in rainwater samples collected in the region of Ribeirão Preto-SP, Brazil. The monosaccharide levoglucosan (1,6-Anhydro--D- Glucopyranose) was proposed as a specific marker for biomass burning, since it is released during the pyrolysis of cellulose at temperatures above 300 ° C. After optimization of the SPE variables, the best conditions were found to be as follows: SPE cartridges filled with the extraction phase chitosan (1,0 g), sample volume equal to 5,0 mL, flow rate of 1,0 mL.min-1 and elution with methanol (volume of 2,5 mL) without added salt. The use of the method SPE/GC-MS for to determination of levoglucosan in rainwater samples was in the range of concentration going from 0,05 to 0,50 g.mL-1, r 0,9967. The accuracy was 95-110%, determination of the inter assay precision gare coefficients of variation (CV) less than 15%, except for the limit of quantification (0,05 g.mL-1), for which CV was less than 20%. According to SPE/GC-MS determinations of levoglucosan in rainwater samples collected between 03/08/2011 and 09/04/2012, the average concentrations of this compound found during the harvest of sugar cane were approximately four times those obtained during the off-season. This fact is explained by the high rate of sugar cane burning in Ribeirão Preto-SP during harvest, which culminates in larger emissions of particulate matter to the atmosphere, including levoglucosano and COD, among others.

A escassez de água no planeta já é uma realidade pontual, inclusive já despontando no horizonte, em nosso país, fora do polígono da seca: na região metropolitana de São Paulo, o modelo de adução, a partir de bacias circunvizinhas, está perto de exaurir, pelos custos que esse tipo de solução adotada desde a época do império romano acarreta nas tarifas para o consumidor final. Assim, a busca pelas chamadas soluções racionais têm, cada vez mais, ganhado adeptos e, dentre estas, a que se tem mostrado mais eficiente e mais eficaz é a tecnologia do esgotamento sanitário a vácuo, visto ser a bacia sanitária a responsável por aproximadamente 40% do consumo residencial de água, e por um percentual semelhante também em edifícios comerciais. A partir do estudo de caso no edifício-sede da Secretaria de Orçamento Federal SOF, em Brasília, foi constatada economia de 30% no consumo médio de água, medido em metros cúbicos, depois da implantação do sistema a vácuo - em substituição ao sistema gravitacional, ocorrida em janeiro de 2008 a par de um aumento de apenas 2% no consumo de energia elétrica, medido em kWh, não produzindo ônus, por força do contrato com a concessionária local de eletricidade, do tipo azul. Foram feitas, ainda, comparações com alternativas de abastecimento, quais sejam água de reuso e o aproveitamento de águas pluviais, este mais comum no Brasil embora nitidamente mais recomendável para construções com até dois pavimentos, enquanto aquele, por enquanto, pode ser considerado uma prospecção teórica para as condições de nosso país / The water shortage in the planet is already a punctual reality that is already rising in our country outside the drought polygon (in northeastern part of Brazil). In the metropolitan area of São Paulo the adduction model coming from the neighboring basins is on the brinks of exhaustion, because this kind of solution costs, adopted since the Roman Empire times, brings up to tariffs to the final customer. In this manner, the search for the so called rational solutions has gained more and more followers and among these the one that has shown more efficiency and accuracy is the vacuum sewerage technology, considering that sanitary basin is responsible for almost 40% of the residential water consumption and a similar percentage occurs also in trade buildings. Taking the case study in the headquarter building of Secretaria de Orçamento Federal (SOF), in Brasília, it was verified a 30% economy in the average water consumption, measured in cubic meters, since the vacuum system was established (replacing the gravitational system), on January 2008, informed about only 2% increase in the electricity consumption, measured in kWh, it means that there was no effective increase in the electricity bill, once the local provide company contract, of the blue type, has foretold small oscillations in the supply without deduction on the bill. It was still done some comparative descriptions with others alternatives water supplies, whichever be grey water and rainwater harvesting, this one widely used in Brazil although it is more suggested to up to two floor buildings while the other, for the time being, can be considered as a theoretical prospection in our country

Esta pesquisa teve como objetivo principal o desenvolvimento de contribuições de natureza técnica para uma proposta de política pública visando a criação de um novo modelo de gestão de águas urbanas, por meio do desenvolvimento e implantação, em escala de lote residencial, de um sistema de gestão integrada da drenagem seletiva e aproveitamento de águas pluviais, e reúso de esgotos sanitários tratados, denominado \"Sistema de Drenagem e Reúso Inteligente\" (SiDRI). A pesquisa foi realizada em um sítio experimental peri- urbano, chamado de Lote Experimental Peri-Urbano, provido de cobertura de telhas de zinco, e os dados resultantes comparados com dados gerados em estudo prévio realizado em outros dois sítios experimentais urbanos, a saber: Laboratórios de Apoio ao Ensino de Graduação-1 e 2 (LAEGs-1 e 2), na área 1 do Campus-1 da USP de São Carlos, respectivamente providos de: telhas prensadas à base de embalagens longa vida recicladas (LAEG -1); e Cobertura Verde Leve CVL (LAEG-2). Para o manejo das águas urbanas em escala de lote residencial foram considerados dois tipos principais de contribuições: 1) Águas advindas de esgotamento sanitário, tratadas em uma fossa séptica biodigestora (FSB) modelo EMBRAPA, e 2) Águas pluviais, captadas e tratadas em um Sistema de Aproveitamento de Águas Pluviais (SAP), cuja concepção básica foi a mesma para os três sítios experimentais. Foram realizadas para o Telhado de Zinco seis séries amostrais consecutivas, para seis eventos de precipitação, em sete pontos de amostragem do SAP, e analisadas 38 (trinta e oito) variáveis de qualidade de água físico-químicas e biológicas. A análise dos resultados, comparada aos demais telhados, sugeriu, face à legislação pertinente, um aproveitamento predominantemente para fins não- potáveis, e desde que mediante prévia desinfecção das águas pluviais. Para a FSB, 15 campanhas de amostragem foram realizadas alternadamente, cujos resultados apontaram uma possibilidade ainda limitada de reuso para o esgoto tratado. Apesar dos resultados do presente estudo indicarem que o novo modelo de gestão de águas urbanas requer adequações, oferecem uma possibilidade de solução para desafios antigos e atuais na gestão das águas urbanas, tendo fornecido elementos para a configuração de uma nova política pública aqui chamada de \"Política Nacional de Gestão de Águas Urbanas\", a qual apresenta interfaces com políticas anteriores, como a Lei das Águas. / This research aimed as its main goal the development of contributions to a proposal for a public policy to the creation of a new urban waters management model, through the development and establishment, at urban lot scale, of an integrated selective drainage system and rainwater use, and reuse of treated domestic sewage, named \"Smart Drainage and Reuse System\" (SD&RS). The research was accomplished at an experimental peri-urban site, named Peri-Urban Experimental Lot, provided by a cover of zinc roof tiles, and its resulting data compared to data generated on a previous study accomplished at another two experimental sites, namely: Undergraduate Learning Support Laboratory-1 and 2 (LAEGs-1 and 2), respectively provided of: compressed tiles made of recycled long-life milk packaging (LAEG-1); and extensive green roof (LAEG-2). For handling of urban waters in residential lot scale, two main types of contribution were considered: 1) Waters from sanitary sewers, treated in a Septic Cesspool Biodigester (SCB) EMBRAPA Model, and 2) Rainwater, collected and treated in a Rainwater Use System (RUS), whose basic conception was the same for the three experimental sites. For the zinc roof, 6 (six) successive sampling series were performed, for 6 (six) rainfall events, in 7 (seven) sampling points of the Rainwater Use System (RUS), and 38 (thirty-eight) physicochemical and biological water quality variables were analysed. The results analysis, compared to the other roofs, suggested, according to the related regulations, a predominant use to non-potable purposes, and since previous rainwater disinfection. For the SCB, 15 (fifteen) alternated sampling series were performed, whose results indicated a still limitated reuse possibility for sanitary sewage. Despite of the results of the present study indicated that the new urban waters management model requires suitability, they offer a possibility of solution to old and actual challenges in urban waters management, since they provided elements for the design of a new public policy named here \"Urban Waters Management Federal Policy\", which presents interfaces with previous policies, like the Water Law.

Thesis (MSc. (Agricultural Economics)) -- University of Limpopo, 2011 / In-field rainwater harvesting technology is the technique that combines the advantages of water harvesting, no till, basin tillage and mulching on high drought risk clay soils. It reduces total runoff to zero, and also considerably reduce surface evaporation. The scarcity of agricultural water is increasing at a faster rate than for other sectors in Limpopo Province. Sufficient, clean drinking water is essential to life, but millions of people throughout the world including South Africa continue to have no access to this basic necessity. This study aimed at investigating the extent and nature of adoption of in-field rainwater harvesting technology by households in Lambani village of Limpopo Province. The main objectives of this study were to identify factors determining the in-field rainwater adoption technology for cropland productivity in Lambani village and to determine the extent to which in-field rainwater harvesting adoption influences cropland productivity in Lambani village. Simple random sampling technique was used to select 70 farmers in Lambani village of Limpopo Province. Data was collected using a structured questionnaire. Descriptive statistics, logistic regression model and linear regression model were used to analyse the data. Descriptive statistics was used to describe the characteristics of households and the nature of Lambani village, and logistic regression model was used to investigate factors that determine the adoption of infield rainwater harvesting technology, while linear regression model was used to determine the extent to which in-field rainwater harvesting influence the cropland productivity in Lambani village. The results from the logistic regression model indicate that 5 variables out of 10 variables are significant in explaining farmers’ adoption decision. Land size, access to financial service, access to information and contact with extension officer are some of the variables that have significantly positive effects on the adoption of infield rainwater harvesting technology, while hired labour has significantly negative correlation with adoption. Variables such as household size, level of education, age of the household, level of income and the main water source do not significantly influence adoption of in-field rainwater harvesting. This information will help prioritize

Groundwater chemistry is a function of recharge and the input chemistry of the rain, which gets transformed as it moves through the soil matrix. Apart from mineral transformations, anthropogenic activities are other external factors, which affect the groundwater chemistry. Stream – aquifer interactions alter the chemistry of groundwater in the regions nearer to the stream. A study is carried out to analyse the hydrogeochemical behavior under the influence of lithologic, precipitation and anthropogenic controls in the upper Cauvery basin. This is followed by the analysis of contributions made by the components of the hydrogeochemical cycle. A geochemical model is developed, which is used to study the spatiotemporal variations in groundwater chemistry of a silicatic rock group in a small experimental watershed. In order to study the effects of precipitation control on the groundwater chemistry the Upper Cauvery river basin (~ 10000 km2) is selected for the analysis, which stretches along three climatic zones – ‘semi-arid’ (500 – 800 mm/year rainfall), ‘sub-humid’ (1000 - 1200 mm/year) and ‘humid’ (1200 – 1500 mm/year) zones. The basin is mainly formed by granitic gneissic group of rocks with some traces of amphibolites and charnockites. Groundwater is observed to occur either in the saprolite or in the deeper hard rock zone based on the geomorphology even at the scale of a small watershed. Parts of this basin are under canal irrigation and are drained by Kabini and Cauvery Rivers. Groundwater – surface water interactions play an important role in these regions. Irrigation with different levels of intensities is practiced through groundwater in the upland areas. Observation wells considered in these three zones are classified into four classes based on the mean annual groundwater fluctuations. Wells in each of these four classes are further classified into ‘shallow’ and ‘deep’ categories based on the depth to groundwater. Analysis of the groundwater chemistry in the basin (widely spread with 120 wells in the three zones) shows a gradient in chemistry along the climatic gradient with sub-humid zone bridging between the semi-arid and humid zones. Ca/Na and Mg/Na ratios decrease from humid zone (unimodal rainfall) to semi-arid (bimodal rainfall) zone since both Na and Mg concentrations in groundwater increase along this gradient. These elements are mainly controlled by weathering reactions. Apart from the weathering of Ca, calcrete formations also play an important role in the semi-arid zone. Ion exchange process cycles between Cl and SO4 and between Ca and Na. Dissolution of CaCO3, silicate weathering and evaporation are the major mineralogical reactions. Variations in Na/Cl and Ca/Cl molar ratios indicate that shallow wells have higher molar ratios with higher variance than the deeper wells. Semi-arid zone is more silicaceous (higher Na/Cl value) than the humid zone, which has higher Ca/Cl ratio (~ 14). Effective seasonal patterns are identified using ‘recharge – discharge’ concept based on the rainfall intensity. Wells under normal scenario have low Na/Cl and Ca/Cl ratios in the ‘recharge period’ than in the corresponding ‘discharge period’ (dilution chemistry). Wells in the relatively higher pumping regions, which receive sufficient annual recharge exhibit dilution chemistry though groundwater level fluctuations are higher. However, wells in regions with insufficient recharge show ‘anti - dilution’ chemistry. Thus, the ‘recharge – discharge’ concept is useful in identifying the pumped wells from deeper wells and helps in characterizing the anthropogenic effects on the basin. Rainfall and its chemistry are to be analysed to understand the groundwater chemistry. Hence, data from various monitoring stations in India are analyzed for assessing the influence of several major factors such as, topographic location of the area, its distance from sea and annual rainfall. These stations are categorized as ‘urban’, ‘suburban’ and ‘rural’. pH, HCO3, NO3 and Mg concentrations have not changed much from coast to inland. On the other hand, SO4 and Ca concentrations changes are subjected to local emissions. Cl and Na (marine elements) originate solely from sea and a model is developed to quantify the variation in concentration of these elements under the influence of inland distance and annual rainfall. Non – linear regression model for the various categories shows that both rainfall amount and precipitation chemistry follow a power law reduction with distance from sea. Cl and Na decrease rapidly for the first 100 km distance from sea, then decrease marginally for the next 100 km and then later stabilize. Regression parameters estimated for different cases are found to be consistent (R2 ~ 0.8). Variation in one of the regression parameters accounts for the effect of urbanization. Model developed for precipitation chemistry is validated using stations from the southern peninsular region of the country. Model predictions are found to be in good correlation with observations with a relative error of ~ 5%. This relationship between the three parameters – rainfall amount, coastline distance, and concentration (in terms of Cl and Na) was validated with experiments conducted at Mule Hole SEW and Kalekere. Monthly variations in precipitation chemistry at these stations are predicted from a downscaled (in time) model and then compared with the observed data. Models developed at both annual and monthly scale are found to perform well with the field observations. Hence, this model is used for predicting the precipitation chemistry (in terms of Cl and Na) of different station points in the upper Cauvery basin. Comparative performance of alternate methods of recharge estimation i.e. Chloride mass balance (CMB) and water table fluctuation (WTF) approaches, is analyzed at various stations in the basin. Annual rainfall, Cl concentration in rain (predicted from precipitation model) and the concentration of Cl in the groundwater are the inputs for the CMB approach. Since main source of Na is from atmosphere, Na is taken as an alternative for Cl in the CMB approach and recharge is estimated using sodium mass balance (SMB) approach. Na concentrations contributed from weathering are quantified and eliminated in the analysis. Recharge estimated using SMB approach is found to be higher than CMB estimate in the semi-arid and the sub-humid zones. Water table fluctuation (WTF) method is used to compare the recharge obtained from both CMB and SMB approaches. Estimates using WTF approach are found to be higher than both CMB and SMB in the semi-arid and the sub-humid zones while SMB is found to be higher than CMB estimates. SMB and WTF estimates match well in the humid zone. An exponential relationship between recharge and annual rainfall is observed. Recharge coefficient estimated on an annual scale varied from 0.1 to 0.25 across the basin. Among CMB and SMB approaches, SMB is a better alternative for recharge estimation in semi-arid zones, where WTF approach performed poorly. Water – rock reactions are driven by the inequilibrium reactions of water with the mineral assemblage in the rock. These reactions evolve towards equilibrium with the primary minerals while a series of secondary minerals precipitate. Mass balance approach is adopted to quantify the rate at which the water – rock interactions occur in order to reach the equilibrium. Field experiments in the experimental watershed (Mule Hole SEW, ~ 4.5 km2) are carried to identify the minerals present in the region and their composition. Quartz, oligoclase, sericite, epidote and chlorite are the primary minerals while kaolinite and Fe-oxides are the secondary minerals present in this region. Percentages of oxides of different elements in each of these minerals are determined from the field experiments. Stoichiometric coefficients of different elements in each of these minerals are determined from these percentages. Long – term weathering rates are determined using these stoichiometric coefficients along with the mass fluxes of each element. Set of minerals present at different depths are found to vary among the thirteen observation wells of Mule Hole SEW. Hence, the mass balance calculations resulted in different weathering rates for a particular mineral based on the spatial location and the particular depth of the occurrence of the mineral. These weathering rates are tested for the sensitivity to carbonates with the inclusion of calcite in the mass balance calculations. With this sensitivity analysis it is observed that the presence of carbonates in the nodular form in the shallow wells has not changed the weathering reactions and their rates, and hence these wells are termed to be in the ‘silicate with secondary carbonate’ system. On the other hand, carbonates are not present in deeper wells, inclusion of which alters the equilibrium of the mass balance calculations. Thus, these wells are said to belong to the ‘silicate’ system. Anorthite present in some of the wells (MH2 and MH6) dissolves accompanied with the dissolution of carbonates. These wells are observed to belong to the third group the ‘amphibolites with primary carbonate’ system. Weathering rates of all the minerals present in these three different systems are also determined annually (short term rates). Mean of these short – term rates are observed to be the same as the long – term (over a period of 4 years) weathering rates with a minor difference of 3 – 10% in values. Thus, the weathering rates determined using mass balance approach is used to determine the quantities of concentrations of different elements contributed from the mineralogical reactions. Temporal variations in the concentrations of different chemical species in this small experimental watershed are simulated using a hydrogeochemical model. The model is developed based on a mixing cell approach, which considers the spatiotemporal variations in the recharge and the weathering inputs. Most of the weathering reactions are observed to take place in the saturated zone, which is termed as the ‘mixing zone’. This zone extends from few meters above the groundwater table to few meters below the water table. Mixing zone is discretized into series of ‘cells’ and concentrations in this zone are simulated. This group of cells is assumed to move along with the groundwater fluctuation. Sensitivity of the model is analysed subject to the variations in the recharge and the weathering fluxes. The developed model is used to simulate the concentrations of the groundwater in the three systems – ‘silicate’, ‘silicate with secondary carbonate’ and ‘amphibolites with primary carbonate’. Field data for chemical species is observed to vary in this mixing zone, boundaries of which are defined from the model simulations. Simulations corresponding to the cell at the mid depth of this mixing zone are observed to correlate well with the field data. Hence, the model developed is able to simulate the temporal variations in the groundwater chemistry. In summary, the study analyses the effects of lithological, climatic and anthropogenic factors on groundwater chemistry. The transformations in the rainwater chemistry as it reaches groundwater are analysed along different stages. A hydrogeochemical model is developed to simulate the groundwater concentrations in three different mineralogical settings over a period of three years.

<p>The access to water in the regions around Lake Victoria varies with the rainy seasons. Today the daily labor of fetching water is a heavy burden for people in the rural areas. In the process of this study farmers in the Western and Nyanza provinces in Kenya are interviewed, water samples are analysed and present rainwater harvesting techniques and purification methods are observed. As a result, suitable solutions to the problems found are discussed. An optimal system is chosen for the region with a concept selection matrix. An elaborated dimensioning tool for roof and purpose-built harvesting systems is developed. Finally a summarized manual is attached in order to raise interest for rainwater harvesting among the farmers that the non-governmental organisation SCC-Vi Agroforestry cooperates with.</p> / <p>Tillgången till vatten i områdena kring Victoriasjön varierar med regnperioderna. Det dagliga arbetet med att hämta vatten är idag en stor börda för människor på landsbygden. Under processen av denna studie intervjuas bönder i Western och Nyanza provinserna i Kenya, vattenprover analyseras och nuvarande regnvatteninsamlingstekniker och reningsmetoder observeras. Som ett resultat diskuteras passande lösningar på de problem som hittats. Ett optimalt val av komplett system för regionerna tas fram med hjälp av en konceptvalsmatris. Ett genomarbetat verktyg för dimensionering av tak- och ändamålsbyggda insamlingssystem utvecklas. Slutligen inkluderas en sammanfattande manual för att väcka intresse för regnvatteninsamling bland de bönder som den ideella organisationen SCC-Vi Agroforestry samarbetar med.</p>

South Africa, in common with many parts of Sub-Saharan Africa, is facing increasing water shortages. Limited available water arising from a low and poorly distributed rainfall, must supply domestic, agricultural, industrial and ecosystem needs. Agricultural activities of smallholder farmers, who largely occupy arid to semi-arid areas, are rainfall-driven as they do not have the capacity to develop conventional water sources, such as boreholes and large dams. This situation has led to persistent food shortages, low income and a lack of investments, resulting in high dependency levels of which examples include over reliance on social grants, household crop production that largely relies on external inputs and availability of cheap unskilled labour. A growing global perception that water for agriculture has low value relative to other value uses could further jeopardize the already over exploited agricultural water. Developing economies such as South Africa are likely to favour, in terms of water allocation, e.g. electricity generation through steam turbines relative to irrigation needs because industry plays a more significant role in the economy. While substantial scientific research has resulted in enhanced yields through in-situ water harvesting and soil and water conservation, as well as crop and soil fertility management and plant breeding, less work has been done to assess the impact of intermittent dry spells on crop yield, particularly with regard to smallholders. Indeed, the interventions that have been promoted to smallholders may provide little buffer against such events. In addition, the increase in yield from many such efforts has been marginal and inconsistent, leading some to conclude that semi-arid environments are hydrologically marginal, have no significant agricultural potential and any attempts to intensify agricultural activities would lead to severe environmental degradation. This study investigated the rainwater harvesting and storage potential among rainfed farmers in a summer-rainfall region of South Africa. The influences of this practice on soil hydraulic properties, water fluxes and crop production is detailed in subsequent chapters. Using historical meteorological data, this study commenced with an investigation of the factors that influence the length of maize (Zea Mays L.) growing seasons notably the prevalence of early season dry spells and late season low temperature which could be responsible for persistent low maize yields amongst smallholder rainfed farmers (Chapter 2). An increasing trend of dry spells was observed which was found to influence sowing dates and the length of the growing season. The influence of no-tillage (NT) as an intervention to secure more root-zone soil moisture was investigated in comparison to conventional tillage (CT) practices. Field experiments, with the aim of quantifying the extent to which water productivity and yields can be improved among smallholder rainfed farmers in the Potshini catchment, Thukela basin; South Africa (Chapter 8), were conducted during both the dry and growing seasons from 2005/06 – 2007/08 seasons at four sites with similar soil textural properties and slopes. Each site was developed as a runoff plot and was fitted with moisture and runoff measuring devices. Meteorological parameters were measured from a weather station installed nearby. A snapshot electrical resistivity survey was used to compliment soil moisture profiling. The analyses of the different measurements provided information on various water flow paths and potential downstream hydrological effects (Chapter 3). The average cumulative runoff was 7% and 9% of seasonal rainfall in NT and CT treatments over the three seasons. Changes over time in soil hydraulic properties due to tillage were examined at two depths through infiltration tests and determination of their bulk densities. These included changes in steady state infiltration rate and hydraulic conductivity (Chapter 4), interaction between soil infiltration and soil characteristics (Chapter 5) and water conducting porosity and water retention (Chapter 6). In 50% of the sites, NT treatments showed significantly higher hydraulic conductivity compared to CT treatments. In response to an unexploited opportunity identified to produce vegetables in winter, an assessment of the potential for runoff water harvesting systems using polyethylene lining as an alternative cost-effective construction method for underground rainwater storage systems, particularly in areas where groundwater levels fluctuate rapidly was undertaken (Chapter 7). The process from conceptualization through design, construction and utilization of the stored water is described and recommendations for the design and construction of such systems made. Finally, various case studies which highlight the potential impact of improved soil profile moisture storage, the additional benefits of water stored in tanks and recommendations for tailored policies to support household food and income generation are made (Chapter 8). / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

Centralized infrastructure (CI) is difficult to sustain with limited water and fossil fuel resources because CI withdraws 100% of water demand from the environment as an open-loop system and electricity is consumed to transport and treat water and wastewater while demand is increasing. Hybrid infrastructure (HI) is proposed to combine CI with decentralized alternatives such as low impact development (LID) technologies (i.e., xeriscaping, rain gardens, and rainwater harvesting) or greywater reclamation systems with membrane bioreactors (MBRs). Water, wastewater, and stormwater systems in the City of Atlanta (COA) were regarded as CI. HI was compared to CI using life cycle environmental impacts measured by water reuse index (WRI) and life cycle assessment (LCA) scores. WRI is a ratio of water withdrawal to sustainable water resources of wastewater (i.e., return flow) and stormwater discharge, which presents water stress level (e.g., 0.2 ~ 0.4: medium-high level). LCA score is determined as % of annual world average environmental damage per capita. As stormwater runoff, water demand, greywater generation, rainwater harvesting, etc. vary depending on land use and population density, feasibility of decentralized alternatives was evaluated in eleven residential communities. Five single-family residential communities were designated as between R-1 of 16 people/10 acres and R-5 of 169 people/10 acres and six multi-family residential communities were designated as between RG-1 of 148 people/10 acres and RG-6 of 5,808 people/10 acres. HI with LID technologies reduced WRI of COA that relies on CI from 0.45 to 0.12. HI reduced the LCA scores of CI with combined sewer system (CSS) by between 1% for RG-6 and 68% for R-1 and the LCA scores of CI with separate sewer system (SSS) by between 0% for RG-6 and 18% for R-1. As population density increases for the multi-family residential communities, harvested rainwater decreases and a small amount of water demand is satisfied. Consequently, it has a negligible impact on the LCA scores in RG-6. HI with greywater reclamation system reduced WRI of COA from 0.45 to 0.35. HI resulted in the LCA scores greater as compared to CI in the five single-family communities and RG-1, RG-2, and RG-3 because of the electricity consumption of small-scale MBR. However, the electricity consumption per kgal decreases with increasing MBR treatment capacity and the LCA scores were reduced by 5% for RG-4, 15% for RG-5, and 21% for RG-6. The MBR treatment capacity of RG-4 is 15.6 kgal/day.

Este trabalho busca estimar a eficiência da economia de água potável no Campus Santa Mônica, Universidade Federal de Uberlândia, utilizando reservatórios de água pluvial para a substituição de água tratada por água de chuva para fins não potáveis. Por meio de informações obtidas junto a Prefeitura Universitária foi possível estimar a demanda diária de água de abastecimento para os Blocos desse Campus, em especial para aqueles com predominância de salas de aulas. A fim de verificar a capacidade de obtenção de água de chuva nas áreas impermeáveis buscou-se no site Hidroweb da Agência Nacional de Águas (ANA) os dados de precipitação diários no período de 1980 a 2015. Com as informações de oferta e demanda de água das principais edificações da área de estudo, construiu-se em Planilhas Eletrônicas, o balanço hídrico diário e a estimativa da eficiência de reservatórios na faixa de volume de 10 a 80m . O período médio de retorno do capital investido variou de 4,1 a 41,3 anos em função das características de cada bloco, tais como: área do telhado, volume do reservatório e demanda. Verificou-se que a escolha do reservatório com base apenas na porcentagem da demanda atendida é ineficaz, o bloco 3Q, por exemplo, apresentou para a demanda 10L/discente.dia uma porcentagem de demanda atendida 32% e 65% superior respectivamente as demandas de 15 e 20L/discente.dia, porém a economia média anual de água potável para a demanda de 20L/discente.dia foi, em média, 9% e 24% maior que as economias médias das demandas de 15 e 10L/discente.dia respectivamente. Além disso, através de uma regressão linear múltipla foram propostas fórmulas para o cálculo da economia anual nos campi da UFU em função do tipo de telhado da cobertura, da população do bloco, do volume do reservatório de armazenamento instalado, da demanda diária por água e da área total da cobertura. Para todos os campi da UFU o coeficiente de correlação R foi superior a 0,83. / This work seeks to estimate the efficiency of the drinking water economy in the Santa Mônica Campus, Federal University of Uberlândia, using rainwater reservoirs to replace rainwater treated water for non potable purposes. By means of information obtained from the University City Hall, it was possible to estimate the daily supply water demand for the Blocks of this Campus Especially those with a predominance of classrooms . In order to verify the capacity to obtain rainwater in the impermeable areas, the daily rainfall data from 1980 to 2015 was searched on the National Water Agency's website (Hidroweb). With the information on water supply and demand Of the main buildings in the study area, it was built on Electronic Sheets, the daily water balance and the estimation of the efficiency of reservoirs in the volume range of 10 to 80m3. The average return period of invested capital ranged from 4.1 to 22.8 years, depending on the characteristics of each block, such as roof area, reservoir volume and demand. It was verified that the choice of the reservoir based only on the percentage of the demand served is ineffective, for example, block 3Q presented a demand percentage of 32% and 65%, respectively, higher than demand Of 15 and 20L / student.day, but the average annual saving of drinking water for the demand of 20L / student.day was on average 9% and 24% higher than the average savings of 15 and 10L / student demands. Day respectively. In addition, through a multiple linear regression, formulas were proposed for the calculation of the annual savings in UFU campuses according to the type of coverage roof, the population of the block, the volume of installed storage tank, daily demand for water and Of the total coverage area. For all UFU campuses the correlation coefficient R was higher than 0.83. / Dissertação (Mestrado)