Riparian buffers in agricultural landscapes are designed to trap pollutants in overland flow by slowing, filtering, and infiltrating surface runoff entering the buffer via sheet flow. However, observational evidence suggests that concentrated flow is prevalent from agricultural fields. Also, over time sediment can accumulate in riparian buffers forming berms that restrict sheet flow from moving into the buffers; these berms ultimately back up surface runoff, resulting in an eventual breakthrough which concentrates runoff. Breakthrough by concentrated flow can lead to gully formation that may reduce the filtering capacities of buffer systems by providing direct conduits to stream channels. This study explores the frequency of concentrated flow paths in riparian buffers at both the field and watershed scale. At the field scale, intensive topographic surveys were conducted at 10 field sites in southern Illinois to characterize concentrated flow paths, accumulated berm sediments, and field area drained by concentrated flow. Detailed digital elevation models (DEMs) were created for each site and riparian buffer and agriculture field characteristics were analyzed to assess the development and occurrence of concentrated flow paths. At each site, soil samples were analyzed to characterize sediment deposition patterns within the buffer. To assess the prevalence of concentrated flow paths at the watershed scale, three watersheds in southern Illinois were selected for walking stream surveys. Five stream segments, approximately 1000 m long, were randomly selected within each watershed and surveyed for the occurrence and size of concentrated flow paths. These data were analyzed with respect to riparian buffer vegetation, buffer width, and surrounding land cover data. Concentrated flow paths were identified in all topographic surveys and all walking stream surveys indicating a common occurrence in agricultural watersheds of southern Illinois. Among field scale sites, concentrated flow accounted for 82.5-100% of the drainage areas contributing to riparian buffers. Results from the watershed scale analysis suggest that concentrated flow paths are significantly more abundant in agricultural land cover, than forested land. Current riparian buffer design principles are based on the assumption that sheet flow is the primary form of surface runoff entering buffers. Furthermore, buffers are installed and not maintained which can lead to berm accumulation and buffer failure. Results from this study indicate that concentrated flow was the prevalent form of runoff at field scale sites. Managers need to consider the occurrence of concentrated flow paths when designing riparian buffers to protect stream water quality.

Made available in DSpace on 2016-06-02T20:00:43Z (GMT). No. of bitstreams: 1 4369.pdf: 12366504 bytes, checksum: d0746d888c77116c1453db230bd4d8b3 (MD5) Previous issue date: 2012-05-03 / Financiadora de Estudos e Projetos / The infiltration well as a Best Management Practices (BMPs) stands out because it requires small areas for its implementation an it´s fully applicable to urban lots. This paper presents an experimental study of an infiltration well built in real scale at Universidade Federal de São Carlos SP with the objective of evaluation its performance as a BMP in the control of stormwater runoff and the removal of suspension materials. The soil was characterized as sand loam, and infiltration capacity between 93,98 and 19,24 mm per hour, these values were obtained thought field tests by the inverted well method and the double ring infiltrometer method respectively. The Rain Envelope Method was used for sizing, and the well was intentionally sized at odds with the standards of safety project. With the electronic equipment s and the precipitation measures were monitored 22 real rain events and simulated rain events, during 11 months of the well operation. During this period there was no record of extravasation of the well, representing an efficiency of 100% in reducing the runoff. After eight months of the well operation tests were conducted about the permeability of the geotextile, and the amount of powder material in the aggregate materials content in the well, in other words, the gravel and sand making up the filter cover, and also the qualitative parameters: apparent color and turbidity. The geotextile showed permeability reductions of 50,7%, 7,7% and 21,2% in the samples from the background, the wall sides, and the cover of the well respectively. The well sand filter cover retained 34,8% of fines, while the gravel retained 0,13% for the same period. About the well efficiency analyses in the removing the parameters apparent color and turbidity, it was showed that it wasn t characterized as a treatment unit of these parameters, this fact is due to the quality of water which represents the roof inlet structure. For modeling the Puls method, the saturated soil permeability defined as K non optimized was calculated for each monitored event (Kno). Kno was adjusted by non-linear regression (K optimized - Ko) for each monitored event, restricting the parameters based on values obtained in the field tests, thus for each monitored rain event was obtained two moldings for the constant values of K (Kno and Ko). The model representativeness was evaluated by the coefficients of determination ranging from 0,68 to 0,98 for the events modeled with values from Ko and 0,02 to 0,76 for the Kno, being the Ko most representative for the modeling of Puls. / O poço de infiltração como técnica compensatória de drenagem, se destaca por necessitar de pequenas áreas para sua implantação e ser totalmente aplicável a lotes urbanos. Este trabalho apresenta um estudo experimental de um poço de infiltração construído em escala real no Campus da Universidade Federal de São Carlos SP com o objetivo de avaliar seu desempenho como estrutura compensatória de drenagem urbana no controle do escoamento superficial e na remoção de material em suspensão. O solo foi caracterizado como Areia Média Argilosa SC, com capacidade de infiltração entre 93,38 mm/h e 19,24 mm/h, valores obtidos em ensaios de campo pelos métodos de poço invertido e de duplo anel respectivamente. No dimensionamento utilizou-se o método da Curva Envelope e intencionalmente não seguiram-se as recomendações de segurança para projeto. Com auxílio de equipamentos eletrônicos e das medidas de precipitação, foram monitorados 22 eventos de chuvas reais e chuvas simuladas, durante 11 meses de funcionamento do poço. Neste período não houve registro de extravasamento do poço, representando uma eficiência de 100% na redução do volume escoado. Após oito meses de seu funcionamento foram realizados ensaios da permeabilidade do geotêxtil, do teor de materiais pulverulentos dos agregados ao poço, ou seja, a brita e a areia que compõem o filtro da tampa, e dos parâmetros qualitativos: cor aparente e turbidez. O geotêxtil apresentou redução média da permeabilidade de 50,7%, 7,7% e 21,2% nas amostras do fundo, paredes e tampa do poço respectivamente. A areia do filtro da tampa reteve 34,8% de finos, enquanto a brita reteve 0,13% de finos no mesmo período. Com relação á remoção da cor aparente e da turbidez constou-se que o poço não caracteriza-se como uma unidade de tratamento destes parâmetros, tal fato deve-se à qualidade da água do telhado que representa a entrada de água na estrutura. Para a modelagem pelo método de Puls a permeabilidade do solo saturado definida como K não otimizado (Kno) foi calculada para cada evento monitorado. O Kno foi ajustado através de regressão não-linear (K otimizado - Ko), restringindo os parâmetros com base nos valores obtidos nos ensaios de campo, dessa forma para cada evento monitorado obteve-se duas modelagens para os valores de K constantes (Kno e Ko). A representatividade do modelo foi avaliada por meio dos coeficientes de explicação que variaram de 0,68 a 0,98 para os eventos modelados com os valores de Ko, e de 0,02 a 0,76 para o Kno, sendo o Ko mais representativo para a modelagem de Puls.

Master of Agribusiness / Agricultural Economics / Terry Griffin / Agricultural runoff containing phosphorus is believed to be a major contributor of algae blooms in the Western Lake Erie Basin. However, the implementation of best management practices (BMPs) can be used to help reduce the runoff of phosphorus. This research involved conducting surveys to analyze the current implementation of BMPs in Michigan and Indiana. The hypothesis is that the survey results are similar between the two states. An additional hypothesis is that the Michigan and Indiana results are similar to results from two other studies that were previously conducted. The results from this research generally support the hypothesis that a similar number of farmers in Michigan and Indiana are already implementing best management practices on their farms. In addition to the results being similar across Michigan and Indiana, there is also some evidence that shows that the results are similar to studies from the Ohio State University (LaBarge and Prochaska 2014), CropLife magazine (Erickson and Widmar 2015) and NRCS (U.S. Department of Agriculture, Natural Resources Conservation Service 2016); however upon further investigation there are distinct differences before and after media mentions of ramifications from the Lake Erie algal blooms. While it is difficult to force farmers to implement BMPs, the results of this study may help to educate them, which may cause them to add these practices to their operations.

Master of Science - Agricultural Education and Communication / Department of Communications and Agricultural Education / Lauri M. Baker / The equine industry is an established part of Maryland Agriculture; the most recent equine census placed 79,100 equines valued at approximately $714 million in the state, with approximately ten percent of those animals housed in Montgomery County. But, equine operators are a unique demographic in the agricultural realm. They are not managing their lands to produce food or fiber and often are employed in other professions unrelated to agriculture. Unlike other agricultural operators, they are often unaware of conservation terms or practices and programs available to help implement these practices on their land. The basic objective of this study was to explore the level of understanding equine operators in Montgomery County, Maryland have of conservation best management practices (BMPs), associated cost-share programs, industry regulations and the aspects and methods of communication that influence them in gaining awareness of and the adoption of these practices on their properties. The study applied the tenets of the decomposed theory of planned behavior (DTPB), which combines the theory of planned behavior (TPB), diffusion of innovation theory (DOI) and economic constraint theory gathered through semi-structured qualitative interviews with participants, selected using purposive and snowball sampling. Utilizing the grounded theory method to discover emerging patterns in the data resulting from these interviews aided in identifying the most effective means of educating equine operators regarding BMPs and increasing the adoption of these practices on equine properties within the County. Equine operators in the study were found to use a variety of informational sources, had a high level of adaptation of the BMPs they used and overall saw their role as land stewards as an important aspect of their environmental actions.

The expansion of urban and suburban areas is a world-wide phenomena. One product of this development is a dramatic increase in impermeable surfaces and a consequent increase in stormwater runoff. Bioretention cells are one best management practice frequently used to mitigate the environmental impacts of urban stormwater runoff. To ensure that a bioretention cell will continue to perform adequately in the long term, it is imperative that the environmental conditions it will experience and their effect on its performance through time are considered during its design. Although bioretention cells are frequently used for stormwater management, very few quantitative data exist on how they perform through time and in varied physical environments. In regions with seasonal freeze-thaw cycles, it is important to understand the effects of freeze-thaw cycles on the infiltration rate of bioretention cell soil mixtures so that the integrity of the design will not be compromised by seasonal change. This project uses laboratory tests to investigate the effects of freeze-thaw cycles and sediment input on the infiltration capacity of three different bioretention cell soil mixtures. These results will provide an analog for long-term changes in bioretention cell infiltration rates due to freeze-thaw cycles, providing critical data on which soil mixture would be best implemented in geographic regions susceptible to freeze-thaw activity. Furthermore these results will inform design standards for bioretention cells to ensure their long-term performance.

Around the world, many forested areas have been and continue to be cleared for expanding agriculture. Canada’s remaining forested lands account for around 9% of the world’s forest cover. Although only a fraction is lost to deforestation annually (0.02%, 2013), Statistics Canada reports that conversion to agriculture is the most significant driver of forest loss. As climate changes and agricultural demand expands, this trend is expected to continue, and ecosystems will continue to be impacted by resulting habitat loss and hydrological changes that can impact infrastructure and communities. Additionally, changes to sediment and nutrient loadings can harm ecosystems and affect the downstream usability of freshwater supplies. The impact of increased sediment and nutrient concentrations in freshwater systems has been extensively documented in the literature. In some extreme cases, it can lead to anoxic ‘dead zones’ in riverine, lacustrine, and marine habitats. Many river systems in Canada have shown elevated nutrient levels in recent years, often tied to the expansion of agricultural land use and destruction of natural forests to increasing nutrient levels in downstream rivers, lakes, and oceans. This study applies numerical modelling to quantify the influence of forest loss, agricultural expansion and the application of best management practices (BMPs) on water quality and quantity in the South Nation Watershed in eastern Ontario, Canada. The land use in the watershed is mainly agricultural (over 60%) with forest (27%) that is unevenly distributed in the basin. Aerial photography surveys from 2008 and 2014 show a steady decline in forest cover. Recent water quality monitoring has shown nutrient concentrations at or above Canadian water quality standards in many parts of the basin. The Soil and Water Assessment Tool (SWAT) was used to model the watershed because of its capacity to simulate comprehensive land management scenarios and assess their impact on a variety of water quantity and parameters quickly and effectively. The work was performed in four steps: 1. Recent land use configurations (2008-2014) in the watershed were acquired, and simplified land use projections based on the direct substitution of cropland for forest land were developed. 2. A numerical model was calibrated and validated for the initial land use scenario. 3. These land use scenarios, as well as more hypothetical scenarios representing more extensive deforestation and reforestation, were used as the basis for hydrological modelling using 31 years of real-world meteorological observations. 4. Idealized vegetated filter strips (VFSs) and grassed waterways (GWWs) were added to the cropped land packages to study the potential of these practices to contribute to the management of water quality. Analysis of the 33 output datasets derived from simulations of the suite of land use scenarios with and without VFSs and GWWs leads to several conclusions, while also raising some questions. Generally, forests significantly reduce sediment, nitrate and phosphorus outputs to streams as well as slightly reducing water yield compared to cropped areas due to an increase in surface runoff, groundwater and lateral flow combined with the absence of tile drainage. Across subbasins, this translates to significant reductions in sediment, nitrate and total phosphorus loadings entering the river reaches and a slight increase in water yield. At the basin outlet near Plantagenet, Ontario, streamflow and sediment loading show to have little sensitivity to changes in forest and crop cover, while increased forest cover leads to significantly reduced nutrient loadings, particularly in late spring and early winter. It is clear from this work that continued deforestation will continue to drive further nutrient enrichment in the South Nation River, while VFSs seems to have a significant potential for offsetting some of this enrichment. Streamflow and sediment loadings, however, are not significantly impacted by foreseeable deforestation. The influence of land use change and BMPs was much more significant in the runoff than in exports from the basin, suggesting there would be value in further examination of water quality and quantity at a higher spatial density to expand on assumptions of in-stream processes made here.

Best management practices are methods that have been determined to be the most effective and practical means of preventing or reducing pollution. Best Management Practices (BMPs) relating to surface water pollution abatement for North Dakota beef cow operations are of particular importance due to the importance of the agriculture industry in North Dakota. North Dakota has yet to address the use of voluntary BMPs to address potential surface water pollution regulations. Probit models were used to estimate the likelihood of North Dakota beef cow operators adopting specific production practices to reduce potential surface water pollution through the use of BMPs. The six BMPs discussed in this research include nutrient management, rotational grazing, filterstrjps, riparian buffers, streambank fencing, and streambank bridging/crossing. Number of beef cows on operation, education, awareness of cost share programs, contact with extension service, ownership structure, debt level, record keeping method, and pasture season usage were found to be significant in the likelihood of adopting a BMP.

<p>A survey of farmers was conducted to determine the extent of cost-share and non-costshare BMP implementation and to evaluate the impact of socio-economic variables of the adoption of BMPs in Virginia's Chesapeake Bay drainage basin. Farmers in 67 counties in Virginia were randomly selected using VirGIS land use data and GRASS 4.1. All of the counties included in the study had at least 90 percent of their total land in the Chesapeake Bay drainage basin. Surveys were mailed to approximately 5,850 farm operators and 1,377 responses were returned, with approximately 1,099 estimated to farm in the Chesapeake Bay basin.</p> <p> A concern for pollution in the Chesapeake Bay was evident by farmers throughout the Bay basin, as 80 percent of the respondents indicated being concerned about water pollution in the Chesapeake Bay. However, only 33 percent believed that their farm contributed to water quality problems. The most often indicated perceived causes of pollution were runoff from urban or paved areas, industrial waste or factory discharge, sewer systems, and litter or garbage.</p> / Master of Science

Anthropogenic eutrophication has become an issue of foremost importance in water bodies all around the globe. Nutrients coming from agricultural activities have been identified as one main contributor to this problem. Technologies and inovations (Best Management Practices, BMPs) have been designed for mitigating agricultural impact on water bodies. However, the problem still persists, partly due to a lack of adoption of these practices by targeted farmers. The Santa Lucía River (SLR) in Uruguay has undergone a process of eutrophication during the last decades, resultingin the implementation of a mitigation plan by the Uruguayan government. The need of collaboration by local farmersin the implementation of BMPs calls for the need of better understanding their perspectives on the process, as well as farmers’ motivations for actively participating in it. To address this knowledge gap, eleven farmers residing in the Santa Lucía River basin (SLRB) were interviewed using a semi-structured interview approach. The farmers were asked about their experiences and opinions on the implementation of BMPs in the SLRB. The obtained data was transcribed and coded using a template analysis approach. This study identified three overarching categories: personal factors influencing motivation, perception of the government, and improvement factors. Within these, eleven factors were identified to depict farmers’ perspectives and/or be influential for their motivations. Results indicate that farmers are motivated and willing to collaborate in the preservation of the SLR’s water, but that there are still many factors that influence their capacity to do so, and must be taken in account in order for this objective to be viable.

Changing climates, human population growth, and aging infrastructure threaten the availability and quality of one of life's most vital resources, water. Hydrological ecosystem services are goods and benefits derived from freshwater that include flood damage mitigation, water for agricultural and commercial use, swimmable and navigable waters, and healthy aquatic habitats. Using computer algorithms inspired by biological and ecological processes known as evolutionary algorithms and on-site stormwater management practices such structural best management practices (BMPs) and green stormwater infrastructure (GSI), this research aims to maximize hydrological ecosystem services at the watershed-scale in both agricultural and urban environments by integrating these algorithms with the watershed model Soil and Water Assessment Tool (SWAT), and the hydraulic model Storm Water Management Model (SWMM). This dissertation first develops an information theoretic approach to global sensitivity analysis for distributed models, demonstrated using SWAT, and later uses the sensitive model parameters in a multi-objective automatic calibration scheme using multi-objective particle swarm optimization (MOPSO). Multiple alternative watershed-scale BMP designs (parallel terraces, detention/infiltration ponds, field borders, and grade stabilization structures) that help minimize peak runoff and annual sediment yield were simultaneously identified using SWAT coupled with the species conserving genetic algorithm (SCGA). Finally, using recently developed economic estimates called triple bottom line (TBL) accounting, watershed-scale GSI designs are identified that reduce combined sewer overflow volumes in an urban setting while maximizing the net benefit across social, economic, and environmental categories. Overall, this dissertation research provides useful and relevant computer-based tools for water resources planners and managers interested in maximizing hydrological ecosystem services benefits.