Biofuel production-driven land-use change in agricultural land can have impacts on ecosystem services. Since there is no planned mandate after the Renewable Fuel Standard, there are questions about what implications will future land-use changes have on water quality and how do water quality changes, resulting from potential bioenergy scenarios, affect changes in people's well-being? To answer these questions, I will estimate the value of the predicted changes in water quality under biofuel policy scenarios in counties inside the Mississippi River Basin. From this study, I found that as the percent of land-use changes increase across each county, water quality decreased. I also found that for every unit increase for the change in water quality index, the percentage of individuals' willingness to pay for a change in water quality would increase. The predicted willingness to pay for a change in water quality for a given household varied from -$72 to $143.

Failure to monitor the quality of drinking water can have devastating consequences. The development and implementation of sensing technology can be a crucial aspect of water quality control strategies. Chemiresistive sensors can be installed at any point of the distribution system and can provide real-time data on the levels of different water quality parameters. These sensors work by detecting changes in the conducting properties of a transducing element, induced by interactions with the analyte. Nanocarbon films have attracted interest as possible transducing materials because of their similarities to graphene, a two-dimensional material known for its exceptional electron transport properties. This thesis explores the fabrication and sensing performance of few layer graphene (FLG) and graphene-like carbon (GLC) films. The FLG sensors were used to detect copper ions in water, while the GLC sensors were used to monitor the concentration of free chlorine. The films were functionalized to improve selectivity and showed noticeable changes in their conducting properties as a result of charge transfer between them and the analyte. These changes were quantified by probing the sensors with a constant voltage and they were found to be dependent on the concentration of the analyte over a wide dynamic range. Overall, the work presented in this thesis suggests that, by tuning the selectivity of the films, nanocarbon based chemiresistive sensors can be a universal solution to water quality monitoring. / Thesis / Master of Science (MSc)

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23499号 / 工博第4911号 / 新制||工||1767(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 米田 稔, 教授 清水 芳久, 准教授 島田 洋子 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Yes / The intrinsic fluorescence of aquatic organic matter emitted at 350 nm when excited at 280 nm correlates widely with water quality parameters such as biochemical oxygen demand. Hence, in sewage-impacted rivers and groundwater, it might be expected that fluorescence at these wavelengths will also correlate with the microbial water quality. In this paper we use a portable fluorimeter to assess the relationship between fluorescence intensity at this wavelength pair and Escherichia coli enumeration in contrasting river catchments of poor water quality: in KwaZulu-Natal, S. Africa and the West Midlands, UK. Across all catchments we demonstrate a log correlation (r = 0.74) between fluorescence intensity and E. coli over a seven-log range in E. coli enumerations on non-perturbed (unfiltered) samples. Within specific catchments, the relationship between fluorescence intensity and E. coli is more variable, demonstrating the importance of catchment-specific interference. Our research demonstrates the potential of using a portable fluorimeter as an initial screening tool for indicative microbial water quality, and one that is ideally suited to simple pollution scenarios such as assessing the impact of faecal contamination in river or groundwater at specific sites. / This research was funded by the UK EPSRC Grant EP/H003061/1.

This research is motivated by an issue frequently encountered in environmental water quality evaluation. Many times, the sample size of water monitoring data is too small to have adequate power. Here, we present a Bayesian power prior approach by incorporating the current data and historical data and/or the data collected at neighboring stations to make stronger statistical inferences on the parameters of interest. The elicitation of power prior distributions is based on the availability of historical data, and is realized by raising the likelihood function of the historical data to a fractional power. The power prior Bayesian analysis has been proven to be a useful class of informative priors in Bayesian inference. In this dissertation, we propose a modified approach to constructing the joint power prior distribution for the parameter of interest and the power parameter. The power parameter, in this modified approach, quantifies the heterogeneity between current and historical data automatically, and hence controls the influence of historical data on the current study in a sensible way. In addition, the modified power prior needs little to ensure its propriety. The properties of the modified power prior and its posterior distribution are examined for the Bernoulli and normal populations. The modified and the original power prior approaches are compared empirically in terms of the mean squared error (MSE) of parameter estimates as well as the behavior of the power parameter. Furthermore, the extension of the modified power prior to multiple historical data sets is discussed, followed by its comparison with the random effects model. Several sets of water quality data are studied in this dissertation to illustrate the implementation of the modified power prior approach with normal and Bernoulli models. Since the power prior method uses information from sources other than current data, it has advantages in terms of power and estimation precision for decisions with small sample sizes, relative to methods that ignore prior information. / Ph. D.

The U.S. EPA has identified pathogen indicators as a leading cause of impairments in rivers and streams in the U.S. Elevated levels of bacteria in streams draining the agricultural watersheds cause concern because they indicate the potential presence of pathogenic organisms. Limited understanding of how bacteria survive in the environment and are released from fecal matter and transported along overland flow pathways results in high uncertainty in the design and selection of appropriate best management practices (BMPs) and in the bacterial fate and transport models used to identify sources of pathogens. The overall goal of this study was to improve understanding of the fate and transport mechanisms of two pathogen indicators, E. coli and enterococci, from grazed pasturelands. This goal was addressed by monitoring pathogen indicator concentrations in fresh fecal deposits for an extended period of time. Transport mechanisms of pathogen indicators were examined by developing a method to partition between the attached and unattached phases and then applying this method to analyze runoff samples collected from small box plots and large transport plots. The box plot experiments examined the partitioning of pathogen indicators in runoff from three different soil types while the transport plot experiments examined partitioning at the edge-of-the-field from well-managed and poorly-managed pasturelands. A variety of techniques have been previously used to assess bacterial attachment to particulates including filtration, fractional filtration and centrifugation. In addition, a variety of chemical and physical dispersion techniques are employed to release attached and bioflocculated cells from particulates. This research developed and validated an easy-to-replicate laboratory procedure for separation of unattached from attached E. coli with the ability to identify particle sizes to which indicators preferentially attach. Testing of physical and chemical dispersion techniques identified a hand shaker treatment for 10 minutes followed by dilutions in 1,000 mg L-1 of Tween-85 as increasing total E. coli concentrations by 31% (P value = 0.0028) and enterococci concentrations by 17% (P value = 0.3425) when compared to a control. Separation of the unattached and attached fractions was achieved by fractional filtration followed by centrifugation. Samples receiving the filtration and centrifugation treatments did not produce statistically different E. coli (P value = 0.97) or enterococci (P value = 0.83) concentrations when compared to a control, indicating that damage was not inflicted upon the cells during the separation procedure. In-field monitoring of E. coli and enterococci re-growth and decay patterns in cowpats applied to pasturelands was conducted during the spring, summer, fall and winter seasons. First order approximations were used to determine die-off rate coefficients and decimal reduction times (D-values). Higher order approximations and weather parameters were evaluated by multiple regression analysis to identify environmental parameters impacting in-field E. coli and enterococci decay. First order kinetics approximated E. coli and enterococci decay rates with regression coefficients ranging from 0.70 to 0.90. Die-off rate constants were greatest in cowpats applied to pasture during late winter and monitored into summer months for E. coli (k = 0.0995 d-1) and applied to the field during the summer and monitored until December for enterococci (k = 0.0978 d-1). Decay rates were lowest in cowpats applied to the pasture during the fall and monitored over the winter (k = 0.0581 d-1 for E. coli and k = 0.0557 d-1 for enterococci). Higher order approximations and the addition of weather variables improved regression coefficients (R2) to values ranging from 0.81 to 0.97. Statistically significant variables used in the models for predicting bacterial decay included temperature, solar radiation, rainfall and relative humidity. Attachment of E. coli and enterococci to particulates present in runoff from highly erodible soils was evaluated through the application of rainfall to small box plots containing different soil types. Partitioning varied by indicator and by soil type. In general, enterococci had a higher percent attached to the silty loam (49%) and silty clay loam (43%) soils while E. coli had a higher percent attached to the loamy fine sand soils (43%). At least 50% of all attached E. coli and enterococci were associated with sediment and organic particles ranging from 8 – 62 μm in diameter. Much lower attachment rates were observed from runoff samples collected at the edge-of-the-field, regardless of pastureland management strategy. On average, 4.8% of E. coli and 13% of enterococci were attached to particulates in runoff from well-managed pasturelands. A second transport plot study found that on average only 0.06% of E. coli PC and 0.98% of enterococci were attached to particulates in runoff from well-managed pasturelands, but percent attachment increased slightly in runoff from poorly-managed pasture with 2.8% of E. coli and 1.23% of enterococci attached to particulates. Equations to predict E. coli and enterococci loading rates in the attached and unattached forms as a function of total suspended solids (TSS), phosphorous and organic carbon loading rates appeared to be a promising tool for improving prediction of bacterial loading rates from grazed pasturelands (R2 values ranged from 0.61 to 0.99). This study provides field-based seasonal die-off rate coefficients and higher order approximations to improve predictions of indicator re-growth and decay patterns. The transport studies provide partitioning coefficients that can be implemented into NPS models to improve predictions of bacterial concentrations in surface waters and regression equations to predict bacterial partitioning and loading based on TSS and nutrient data. Best management practices to reduce bacterial loadings to the edge-of-the-field from pasturelands (regardless of management strategy) should focus on retention of pathogen indicators moving through overland flow pathways in the unattached state. Settling of particulates prior to release of runoff to surface waters might be an appropriate method of reducing bacterial loadings by as much as 50% from highly erodible soils. / Ph. D.

Temperate agroforestry systems are an important area of research and practice in Eastern North America with the goal of creating more diverse, productive, and environmentally sound agricultural landscapes by using trees as key crops. There is extensive published research on contemporary temperate agroforestry models as well as tropical indigenous agroforestry systems, but publicly accessible properties that demonstrate these practices are currently limited. These practices, which include: Alley Cropping, Multi-functional Riparian Buffers, Short-rotation coppice, Non-timber forest farming, and novel crop breeding have potential to radically reshape American agricultural practices. As sediment and erosion control becomes stricter in agricultural land, and if future carbon tax or pricing legislation comes into play, non-tillage based agricultural practices will become more prevalent throughout the United States and the rest of the world. In the Mid-Atlantic region of the United States, where this project is based, orchards are a common perennial cropping system, but at present the industry is reliant on chemical inputs that have an economic and ecological cost associated with them. Developing, demonstrating, and popularizing systems that incorporate native, crop-bearing perennials, in a manner that is legible, aesthetically pleasing, and well-integrated into the surrounding topography and agricultural vernacular, this thesis will offer a proof-of-concept to landowners curious about incorporating low-input agroforestry practices. This thesis presents a series of unpublished manuscripts based on research of historical agroforestry practices in temperate North America. These manuscripts focus on agroforestry practices as they were practiced over nearly 500 years of American history. These findings culminate in the proposition of a design for an agroforestry research and demonstration farm in the Mid-Atlantic United States. The goal of this design is to recontextualize a historic dairy farm in Maryland, USA with the construction of a new education, production, and design center. This center, along with its associated infrastructure, the cropping layout, and an interpretive trail through a range of agroforestry systems proposes an immersive environment that allows a visitor to experience agroforestry at its many scales, from garden to wild-land. / Master of Landscape Architecture / Temperate agroforestry systems are an important area of research and practice in Eastern North America with the goal of creating more diverse, productive, and environmentally sound agricultural landscapes by using trees as key crops. There is extensive published research on contemporary temperate agroforestry models as well as tropical indigenous agroforestry systems, but publicly accessible properties that demonstrate these practices are currently limited. These practices, which include: Alley Cropping, Multi-functional Riparian Buffers, Short-rotation coppice, Non-timber forest farming, and novel crop breeding have potential to radically reshape American agricultural practices. As sediment and erosion control becomes stricter in agricultural land, and if future carbon tax or pricing legislation comes into play, non-tillage based agricultural practices will become more prevalent throughout the United States and the rest of the world. In the Mid-Atlantic region of the United States, where this project is based, orchards are a common perennial cropping system, but at present the industry is reliant on chemical inputs that have an economic and ecological cost associated with them. Developing, demonstrating, and popularizing systems that incorporate native, crop-bearing perennials, in a manner that is legible, aesthetically pleasing, and well-integrated into the surrounding topography and agricultural vernacular, this thesis offers a masterplan to create a proof-of-concept demonstration site to landowners curious about incorporating low-input agroforestry practices. This thesis presents a series of unpublished manuscripts based on research of historical agroforestry practices in temperate North America. These manuscripts focus on agroforestry practices as they were practiced over nearly 500 years of American history. These findings culminate in the proposition of a design for an agroforestry research and demonstration farm in the Mid-Atlantic United States. The goal of this design is to recontextualize a historic dairy farm in Maryland, USA with the construction of a new education, production, and design center. This center, along with its associated infrastructure, the cropping layout, and an interpretive trail through a range of agroforestry systems proposes an immersive environment that allows a visitor to experience agroforestry at its many scales, from garden to cultivated wilds.

A Colorimetric Coliphage Assay Detection System (CCADS) that is composed of a Liquid Colorimetric Presence-Absence (LCPA) method and a Colorimetric Agar-Based (CAB) method was developed to overcome the limitations imposed by the Standard Methods for the Examination of Water and Wastewater agar-based coliphage method (APHA method). Both CCADS methods are based on the induction of β-galactosidase in Escherichia coli and the release of the enzyme through a lytic cell infection. The released enzyme then cleaves a chromogenic substrate which produces a colored reaction product. The CCADS was evaluated against the APHA method under laboratory conditions using a common sewage coliphage strain as a model (American Type Culture Collection- 13706-B2), and under field conditions using water samples collected from four different sources. During the laboratory evaluation, both the LCPA and CAB methods were found to be superior in coliphage detection to the APHA method because: 1) the LCPA and CAB methods were easier to read and interpret than the APHA method, 2) the LCPA and CAB methods were not subject to false positive results, 3) the LCPA method theoretically detected fewer coliphage particles than the APHA method, and 4) the CAB method detected roughly twice the number of coliphage particles than the APHA method. During the field evaluation, the results indicated: 1) the LCP A method was as reliable as either the CAB or APHA methods in coliphage detection, 2) the LCP A and CAB methods were easier to read and interpret than the APHA method, 3) neither the LCPA method nor the CAB method were subject to false positive results, 4) the CAB method detected more coliphages than the APHA method under conditions of high fecal pollution, but both methods performed equally well in coliphage detection under conditions of low fecal contamination, and 5) the LCPA and CAB methods were equally as sensitive in coliphage detection as the APHA method. Finally, the coliphage group proved to be a useful indicator of fecal pollution in nonpotable water supplies that exhibited a high degree of fecal pollution, whereas they were not shown to be useful indicators in potable water supplies that exhibited low levels of fecal contamination. The lack of coliphage detection sensitivity under conditions of low fecal contamination does not appear to be method limited, but rather the result of inefficiencies in processing environmental samples using the concentration methods currently available. / Ph. D.

To protect the integrity of the United State's waters, the Federal Water Pollution Control Act of 1972 promoted the establishment of Best Management Practices (BMPs) for forestry. A commonly used BMP is the reservation of Streamside Management Zones (SMZs). In this study the effectiveness of three different SMZ widths, 30.5 m (100 ft), 15.3 m (50 ft), and 7.6 m (25 ft), as well as thinning in 15.3 m SMZs were studied. The objectives of the study were to determine the effects these SMZ treatments had on carbon pools, carbon fluxes and environmental conditions in the SMZ. The benthic macroinvertebrate populations present within the stream were also examined because of their relationship to ecosystem carbon dynamics. Carbon storage in plant communities, litter layer, soil (upper 10 cm), and total organic carbon present (TOC) within streams were measured and quantified. Total CO₂ efflux and the major environmental drivers of soil CO₂ efflux, soil moisture and soil temperature, were monitored along a single transect within each SMZ. This study showed that carbon dynamics and stream biota (benthic macroinvertebrates) were not adversely effected by more narrow SMZ width and thinning within the SMZ. SMZ width did affect soil temperature, one of the environmental drivers affecting soil respiration. Based on these short-term results a 15.3 m SMZ with thinning or without thinning appears adequate to prevent changes in ecosystem function and water quality for forest applications. / Master of Science

The Streamside Management Zone (SMZ) is a cornerstone of forestry Best Management Practices to protect streamwater quality from non-point source pollution resulting from silvicultural operations. However, the exact width and harvest intensity of SMZs that best protects water quality while allowing for commercially valuable timber harvesting has not been determined. The long-term objective of this study is to characterize SMZs and watersheds before and after harvest with different SMZ widths and harvesting intensities in the Allegheny Plateau of West Virginia. The objective this paper is to present the pre-harvest SMZ and watershed characterization. Each of the watershed SMZs were characterized pre-harvest in terms of vegetation, water, soil, carbon, and monetary value within SMZs to predict how silvicultural treatments will affect the future stands. The major overstory tree species found are Acer saccharum, Liriodendron tulipifera, Fagus grandifolia, Tilia americana, Betula lenta, snags, Betula lutea, Fraxinus spp., and Acer rubrum. The overall average streamwater temperature is 13°C. Highest daily temperature occurred in the mid-afternoon and lowest temperatures occurred just before sunrise. Streamwater quality was good, with near neutral pH, low nitrogen content, and high dissolved oxygen. USLE erosion estimates predicted an erosion rate of 2.9 Mg/ha/yr in the SMZ. However, the sediment rods showed an overall accumulation of soil in the SMZ, averaging 173 Mg/ha/yr. This equates to an average watershed loss of 10.9 Mg/ha/yr. In-stream and SMZ LWD volume was approximately equal at 28 and 33 m3/ha. Large woody debris was more decayed in the SMZ than in-stream LWD. / Master of Science