Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1987. / Includes bibliographical references (leaves 149-151).

Thesis (M.S.)--Missouri University of Science and Technology, 2010. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 8, 2010) Includes bibliographical references (p. 59-60).

Tanto no meio rural como urbano as novas tendências são de buscar uma melhoria de técnicas e de uso de materiais alternativos buscando-se uma maior sustentabilidade. A utilização de plantas nas paredes e telhados é um dos mais recentes campos da pesquisa ambiental e busca encontrar uma solução ecológica e sustentável para melhorar a qualidade de vida urbana e rural. Uma cobertura verde consiste de um substrato leve e de uma vegetação apropriada, plantada sobre uma base impermeável. Podem conter também camadas adicionais, tais como, um sistema de drenagem e irrigação e uma barreira anti-raízes. Os efeitos positivos da vegetação sobre o ambiente urbano já são bem conhecidos e neste caso da cobertura, diminuem as enxurradas, filtro biológico, redução da poluição do ar, amenizam o calor nas edificações durante o verão e o conservam durante o inverno. Há também benefícios para a fauna, com retorno de espécies que mantêm o equilíbrio biológico local. Essas coberturas podem ter muitas aplicações, como em indústrias, residências, escritórios e outras propriedades comerciais e rurais. Uma criteriosa seleção de plantas permite que a cobertura verde tenha sucesso em condições adversas. Por outro lado, são necessárias pesquisas no sentido de assegurar um meio de cultura que retenha água e ao mesmo tempo proporcione uma boa drenagem para que as raízes não apodreçam, permitindo uma maior gama de espécies de plantas na cobertura. Neste sentido, realizou-se um estudo dos substratos mais abundantes na região, buscando tecnologias apropriadas para a confecção dos telhados verdes e identificando as melhores técnicas de aplicação, de acordo com a necessidade de cada ambiente. Para a realização deste trabalho foram utilizados dez tipos de substratos que foram pré-selecionados de acordo com a disponibilidade no mercado, de mais fácil obtenção e de melhor custo beneficio ambiental. As análises estatísticas utilizam o delineamento experimental inteiramente ao acaso, em esquema fatorial com três repetições e utilizando o programa estatístico SAS para auxiliar na análise e confecção dos gráficos e discussões. Na avaliação do conjunto de características, a turfa marrom (TM) apresentou o menor valor de densidade seca, maior porosidade total, maiores valores de água facilmente disponível, água disponível e capacidade de retenção de água, e mesmo valor de espaço de aeração daquele sugerido como referência sendo um bom material para o uso em telhados verdes, formando compostos com outros materiais e buscando as melhores características e sustentabilidade do sistema. Dentre os substratos comerciais estudados, o substrato para espécies hortícolas (SH) apresentou os maiores valores de capacidade de retenção de água e água disponível para as plantas, possibilitando um maior intervalo entre irrigações ou chuvas, características importantes para o uso em telhados verdes. No entanto, tornam-se necessários mais estudos com a finalidade identificar mais materiais e substratos apropriados para o uso em telhados verdes, levando-se em conta as diferentes características de cada local, tipo de vegetação escolhida, capacidade de suporte da edificação, dentre outro fatores. / Rural and urban new trends seek an improvement in techniques and use of alternative materials for greater sustainability. The use of plants on walls and roofs is one of the newest fields of environmental research, looking for a green and sustainable solution to improve the quality of urban and rural life. A green cover consists of a substrate and appropriate vegetation planted on an impermeable base. It can also contain additional layers, such as a system of drainage and irrigation with an anti-root barrier. The positive effects of roof vegetation on urban environment are well known, as reducing the runoff,acting as a biological filter, reducing air pollution, minimizing heat inside the buildings during summer and maximizing during the winter. There are also benefits to fauna, with the return of various species, maintaining the local biological balance. The coverage can be adapted to industries, homes, offices and other commercial and rural properties. Careful selection of plants allows the green roof to succeed in adverse conditions. In addition, research is necessary to ensure a culture medium that retains water that the same time provides good drainage to prevent root rot, allowing a wider range of plant species in the cover. In this sense, a study was conducted involving the most abundant substrates of our region, seeking appropriate technologies for the manufacture of green roofs and identifying the best application techniques, according to the needs of each environment. For this work ten types of preselected substrates were used according to market availability, easier to obtain and with a better environmental cost/benefit ratio. Statistics of the experimental design was completely randomized in a factorial format with three replications and using the SAS statistical software to assist in the analysis and construction of graphs and discussions. In evaluating the feature of the cover set, brown peat (TM) presented the lowest value of dry density, higher porosity, higher values of easily available water, available water capacity and water retention, and even the amount of aeration space, suggested TM as being a good reference material for use in green roofs. Among the studied commercial substrates, the substrate for horticultural species (SH) showed the highest values of water holding capacity and water available to plants, allowing a longer interval between irrigations or rainfall, an important characteristic for its use on green roofs. However, more studies are needed in order to identify the most suitable materials and for use in green roof substrates, taking into account the different characteristics of each site, vegetation type, bearing capacity of the building, among other factors.

The objective of this study is to develop guidelines for the analysis of storm water retention ponds in Central Florida. Development of a combined seepage analysis considering both unsaturated and saturated groundwater flow incorporation into a systematic approach for storm water retention pond design will result in safer and more economical storm water management practices. The research was conducted in four phases: 1) A literature review. 2) A review of mathematical and empirical analysis of transient – unsaturated/saturated groundwater flow. 3) Construction and testing of a downscaled storm water pond model. 4) Incorporation of full scale percolation pond test data from ponds constructed and tested in Central Florida. The literature review was undertaken to research mathematical and empirical equations for both unsaturated and saturated groundwater seepage to be incorporated into the modelling and development of final system analysis. The review was concentrated on seepage studies conducted in subsoil conditions similar to those in Central Florida. It was found in the early review of literature that separate studies and modelling for unsaturated and saturated seepage are widespread and relatively well documented. However, documentation of combined groundwater seepage model, since the majority of storm water retention ponds in Central Florida experience both seepage condition (unsaturated/saturated) during the design storm event. Inspection of operational seepage ponds and interviews with regulatory agencies and consulting firms in Central Florida indicated that successful design of storm water retention ponds greatly depends on the accurate definition of the subsoil conditions and the seepage characteristics during a specific design storm event. Interviews with those responsible for pond design revealed that there is currently no widespread accepted design method, and most of the designs are based on mostly local experience. Also, history indicates that even though the unsteady seepage analysis is a complex phenomenon, there is usually very little money I the budget for its analysis and design. However, due to continuous increase of property values and the need to optimize pond sizing, the trend of under budgeting for seepage bond design is reversing. Application of the research results will yield a more accurate analysis which accounts for unsaturated and saturated seepage for sizing of storm water retention ponds in Central Florida. The analytical solutions developed from this research are a combination of acceptable mathematical and empirical groundwater seepage equations or dimensionless graphs modified for the purpose of storm water retention pond analysis.

Stormwater detention systems as they are frequently designed do not provide good water quality control of stormwater runoff. A filtration media to be used in conjunction with detention ponds to improve their pollutant removal efficiencies was tested at the University of Central Florida and found to be effective. The filtration media, which consisted of a mixture of sand and alum sludge, substantially improved effluent water quality. Average reductions of over 80 % were observed in concentrations of dissolved orthophosphorus, total orthophosphorus and total phosphorus. Reductions were also experienced in iron, aluminum, copper and zinc concentrations. A prototype filtration model is presently being tested on the Lake Eola watershed in Orlando, Florida. A stormwater management and design aid computer program originally written by Tim Curran (Curran 1980) to calculate stormwater hydrographs and retention volumes, and updated by the author to also calculate detention volumes will incorporate results from the prototype study.

The operation and maintenance of highways contributes a variety of pollutants to surface and subsurface waters. Solids, heavy metals, nutrients, oil and grease, pesticides and bacteria can all be associated with highway runoff. Although the full extent of the effect of all of these runoff constituents upon the quality of surrounding waters is not well defined, this study will mainly concentrate on nutrient contaminants (essentially nitrogen). The last decade has seen increasing efforts in research and development to abate contaminant discharges from highway runoff using a number of treatment facilities such as retention/detention basins, swales and wetland systems. An evaluation of the effectiveness of these systems in removing nitrogen by physical, chemical and biological uptake is the aim of this research endeavor. This information could prove invaluable in an overall assessment of the effectiveness of highway runoff treatment systems.

M.S.

This study analyzed data that had been previously collected by the Occoquan Watershed Monitoring Laboratory under the National Urban Runoff Program, to obtain an understanding of the degree of treatment of stormwater runoff obtainable in retention (maintains a water pool) and detention (drains completely) basins. Three basins were studied, two retention and one detention, and a total of 191 storm events were monitored using automatic sampling equipment. The samples were analyzed by the laboratory for COD, all nitrogen forms, all phosphorus forms, total suspended solids, and heavy metals (iron, manganese, etc.). It was concluded that detention and retention ponds achieve substantial reduction in the pollutant loads carried by stormwater runoff from residential areas. Non-soluble settleable materials were removed to a comparable degree by both basin types. However, the pool of water characteristic of a retention basin offered a superior environment for the removal of soluble pollutant forms, particularly nitrogen and phosphorus. The treatment obtainable in detention and retention basins make them effective devices for the abatement of urban runoff pollution. Through the mechanisms of solids settling and microbial degradation, a basin can treat polluted runoff to a considerable extent and reduce damage to receiving bodies of water. / M.S.

Diversion of the first flush of storm runoff to a detention basin for pollutant removal is an efficient way to control nonpoint source pollutant in urban areas. This can be achieved by a diversion box and detention basin system. To numerically simulate the response of the system to a design rainfall event and the associated pollutant loadings for a given drainage area, a desk top model has been developed for"user-friendly"' application in personal computers. Hydrographs and pollutographs are generated at the inlet and outlet of the diversion box and the detention basin.These hydrographs and pollutographs are examined and the peak outflow and peak pollutant concentrations are compared with allowable outflow and pollutant concentration for urban stormwater quality and quantity management. This model is designed for both the analysis and design of the system. / M.S.

Laboratory-scale settling columns were used to determine the settling velocity distributions of suspended solids to refine a methodology selected by the FHWA in designing wet detention basins for the treatment of highway stormwater runoff. Thirteen runoff samples were collected, over two years, from high volume (greater than 100,000 vehicles per day) highways in the Northern Virginia area. The sampling sites drained only highways and associated rights-of-way. Approximately 5.5 gallons of stormwater were placed in Plexiglass columns, and samples were withdrawn from column sampling ports immediately following sample addition, and after two, six, twelve, twenty-four, and forty-eight hours. Sampling depths along the column, were at one, two, and three feet from the base of the column. Each sample was analyzed for total suspended solids, five total and dissolved heavy metals, total Kjeldahl nitrogen, nitrate-nitrite nitrogen, total and dissolved phosphorus, and pH. Orthophosphorus, temperature, and total dissolved solids were analyzed only during the first year. The resulting analysis determined that highway runoff is similar to urban runoff in distribution and settling characteristics. Correlations between suspended solids removal and the removal of other pollutants were developed. The settling velocity distribution found in this study resulted in the revision of the FHWA design methodology for wet detention basins. / Master of Science