Protecting water quality, biota, and ecosystem services of streams (cumulatively referred to as stream health) while increasing food production is a major global challenge. One way to balance these often-competing interests is through the installation of agricultural conservation practices, such as excluding livestock from streams via fencing and adjusting grazing patterns. However, conservation practices often do not improve stream health as expected. Failure to achieve stream health outcomes may be due to biophysical (e.g., conservation practices are not appropriate for the landscape) or social reasons (e.g., agricultural producers are not willing to use conservation practices). Therefore, the goal of my dissertation research was to understand factors influencing effectiveness of conservation practices using an interdisciplinary approach that integrates ecological engineering, ecology, and social science. My research focuses on southwest Virginia, a karst region where cattle grazing is common. In the introduction, I developed a social-ecological framework that outlines how the natural and social sciences can be used to guide effective placement and implementation of conservation practices and explain why interdisciplinary approaches are often necessary due to social-ecological connections that influence efficacy (i.e., feedbacks, heterogeneity, time lags, and thresholds). In Chapter 1, I modeled pollutant transport to characterize watershed features that contribute disproportionate amounts of pollutants to streams. I found that water, and associated nitrate, is primarily entering streams through subsurface pathways, whereas sediment is entering the stream through streambank erosion. Therefore, a combination of conservation practices that stop nitrogen at its source (e.g., nutrient management plans) and stabilize streambanks (e.g., fenced riparian buffers) could be useful for protecting stream health. For Chapter 2, I sampled water quality, habitat, and macroinvertebrates from 31 streams within sub-watersheds that span a range of pollutant yields, conservation practice densities, and agricultural land use extent to understand the pathways through which conservation practices influence stream health. Agricultural land use increased total nitrogen and decreased macroinvertebrate diversity, but conservation practices stabilized nitrogen and improved bank stability. Despite such improvements, adverse effects on water quality and habitat still limited the biotic assemblage. Therefore, innovative conservation practices, higher densities of existing practices, or allowing more time for the effects of existing practices to improve water quality and habitat may be required to achieve stream health goals. For Chapter 3, I surveyed producers to understand if they continue to use their conservation practices after their cost-share contracts end (i.e., persistence) and factors that influence persistence. Persistence was most strongly related to producers' attitudes towards the conservation practice, producers' motivations, and practice durability. Therefore, persistence could be encouraged by using producers' motivations to focus messaging on ways conservation practices are achieving producers' goals and allocating more funding to practice maintenance. Overall, my interdisciplinary approach led to a greater understanding of pollutant dynamics, the pathways through which conservation practices influence stream health, and social constraints to persistence. This knowledge can inform what conservation practices may be most effective and strategies to keep appropriate practices on the landscape long enough to achieve stream health goals. / Doctor of Philosophy / As farmers work to feed a growing worldwide population, streams can inadvertently receive pollution, like excess sediment and nitrogen. Too much sediment can clog the gills of aquatic animals and reduce their habitat, and too much nitrogen can cause excessive plant growth and decrease the amount of oxygen in the water. The cumulative effects of pollution from farming can result in streams being unable to support human uses such as clean drinking water and fishing opportunities. To increase food production while protecting streams, government agencies help farmers pay for the costs of using conservation practices that can reduce pollution. Examples of conservation practices include keeping livestock out of streams with fences, ensuring the ground is covered with plants in between planting crops, and developing a plan for the maximum amount of fertilizer that can be used. Unfortunately, conservation practices are sometimes ineffective, and streams still become polluted despite their use. My goal was to understand why some conservation practices are ineffective and how conservation practices might be improved for southwest Virginia. In the introduction, I developed a framework that illustrates how connecting the natural and social sciences can improve conservation practice efficacy by guiding planning and placement of new practices. In Chapter 1, I used a computer program to simulate pollution within streams so that I could understand which locations have the greatest amount of pollution and why. I found that nitrogen typically enters streams through the water in the soil rather than water running over the land surface and that sediment mostly enters the stream through erosion of the streambanks. These results suggest that conservation practices such as limiting the amount of nutrients placed on the landscape could be especially effective for reducing nitrogen pollution, whereas building fences to exclude cattle from streams and planting trees along streams can help reduce sediment pollution. For Chapter 2, I visited 31 streams in southwest Virginia that had varying amounts of pollution and conservation practices and collected water quality, habitat data, and aquatic insects. All these metrics are good indicators of pollution, but aquatic insects are particularly excellent indicators because their populations respond to cumulative changes in habitat and water quality. Streams with more conservation practices did not exhibit more diverse insect communities but did show stabilized water quality and habitat. These results indicate that the types of conservation practices currently used are not completely protecting streams and farmers may need to use more practices, new types of practices, or use their current practices for longer periods of time. For Chapter 3, I surveyed farmers to find out if they continue to use their conservation practices after funding from agencies ends, as well as their motivations for their actions. Farmers indicated that they were more likely to continue using conservation practices if their goals for using the practice were achieved and that they had difficulty keeping fences and trees from being destroyed by floods and wildlife. Government agencies could increase continued use of conservation practices by showing farmers how the practices are achieving their goals and by providing more funding to maintain practices. By combining research from several fields of study, I was able to better understand which conservation practices would be most effective in protecting streams and new ways to support farmers in using conservation practices.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Kyle R. Douglas-Mankin / Water quality trading (WQT) is a market-based approach to improve water quality. It is an innovative, voluntary program that connects point source (PS) dischargers who need to reduce their pollutant loads with land managers who could offset those loads with nonpoint source (NPS) reductions to economically achieve water quality improvements in a watershed. The potential issues impeding WQT are its inability to address trading risks and quantify the uncertainty of potential load reduction in trades between PS and NPS. Recent research has also shown that trading information level and transaction costs cause problems in implementing WQT. Therefore, the goals of this study were to quantify the uncertainties of pollutant load reduction and delivery effect for potential trades, to estimate their spatiotemporal variations, and to provide information for stakeholders to reduce intangible costs of WQT. This study simulated agricultural cropland with more than 225 alternative land management practices to identify trends among these scenarios. Both total nitrogen and total phosphorus loads were modeled with SWAT and EUTROMOD for 36 years to analyze the potential load reduction, in-field uncertainty ratio, in-stream delivery ratio, and overall trading ratio (TR) in Lower Kansas watershed, Kansas. The analyses of site-specific effects in both geospatial and temporal aspects were also applied on subbasin level. The variant loading patterns and time distributions of each subbasin showed strong site-specific phenomena. The ANOVA of in-field nutrient load showed significant differences among the design criteria of scenarios. The results also showed a significant delivery and lake effects within the subbasins. The overall TR ranged from 1 to 2.2 or more in different scenarios. The advanced cluster analysis presented a potential method to eliminate the problems involved in fixed TRs while keeping the method simpler than finer-resolution floating TR system. Based on WQT geospatial data model, a three-tier GIS-based web interface Water Quality Trading Information Platform System (WQTIPS) was then developed for WQT information and assessment. A case study demonstrated WQTIPS can provide systematic, spatially information for stakeholders to assess the potential environmental benefit changes from the land management shifts using a simple interface. This study demonstrated that it is possible to automate water-quality trades, use watershed models to minimize trading risk and maximize water-quality benefits, and prioritize among possible trades both spatially and by BMP.

The State of Kuwait has three large refineries, namely, Mina Al Ahmadi Refinery, Mina Abdullah Refinery and Shuaiba Refinery. These refineries process and refine Kuwait Crude Oil through different process units. There are many heaters, boilers and flares that form a part of the complicated equipment which enhance the different petroleum processes. Fuel gas is used as a firing fuel for those heaters and boilers. As a result, stack emissions like SO2, NOx, CO are predominantly present in the flue gases and this study focuses on those emissions and their impact on the surrounding residential area. The area of interest will be Umm Al-Hyman residential area. This study accumulates emission inventories from the three refineries and the respective ground level concentration of the pollutants in the neighboring residential area. It also focuses on the impact of emissions from the refinery operations on the ground level concentrations in the surrounding areas by using the inventory model and latest emission factors to provide accurate emission estimates. The models were developed and the results were verified with the actual data from the area of impact. As a result of the findings of the major pollutants, namely SO2, NOx & CO, it is found that SO2 and CO are not exceeding Kuwait EPA Ambient Air Quality Standards for Residential Areas normally. However, NOx is observed to exceed occasionally. Even though, NOx emissions from refineries sources represented by plume models were much less, there is a consistent increase in the measured NOx. Furthermore, in 2007, the measured hourly, daily and annual NOx concentration exceeded the international standard many times. The increasing trend in NOx is attributed to continuous increase in population and the number of motor vehicles. The study will go further step in recommending engineering solutions and best practices to reduce the pollutants concentrations which will help in the reduction of human health risks and protect the environment.

Tidal freshwater reaches of estuaries may play an important role in mitigating nutrient fluxes from watersheds to the coastal zone due to their location at the interface between riverine and estuarine systems. We developed annual N and P budgets for the tidal, freshwater James River over 4 calendar years (2007-2010) taking into account riverine inputs at the Fall Line, local points sources (including CSO events), ungagued inputs, riverine outputs, and tidal exchange. The tidal freshwater James River experiences high areal loading rates of TN (383 mg/m2/d) and TP (70 mg/m2/d) due to the combined effects of large watershed area and local point source discharges. On an annual basis, riverine sources dominated TN and TP inputs (59% and 84%, respectively), whereas during low discharge summer months (May-Oct) point sources were more important. Proportional retention of TP inputs (59±7%) was greater than TN retention (27±4%) with annual absolute retention being 1,800±350 kg TP/d, and 5,900±2,700 kg TN/d. Proportional retention of TN and dissolved inorganic fractions of N and P was highest during the low discharge summer months due to reduced loading rates and increased residence times and biotic activity. TP retention was greatest during high discharge winter months (Nov-Apr) when loading rates were highest. High retention during this period of low biotic activity suggests that trapping of riverine derived particulate-bound P via sedimentation was an important mechanism of P retention. Understanding this seasonal variation in nutrient inputs and retention can help to inform management decisions regarding reducing nutrient inputs to the Chesapeake Bay and improving local water quality.

Sampling data of many surface water bodies in Broward County tend to reveal abnormal levels of bacterial concentrations for total coliform, Escherichia coli and Enterococcus. Given the presence of septic systems in geohydrologically sensitive areas throughout the County, several studies (Morin 2005 and Bocca 2007) suggested a correlation in the high bacterial densities and the septic sites. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

The Finite Difference Time Domain (FDTD) Method has been a powerful tool in numerical simulation of electromagnetic (EM) problems for decades. In recent years, it has also been applied to biomedical research to investigate the interaction between EM waves and biological tissues. In Wireless Body Area Networks (WBANs) studies, to better understand the localization problem within the body, an accurate source/receiver model must be investigated. However, the traditional source models in FDTD involve effective volume and may cause error in near field arbitrary direction. This thesis reviews the basic mathematical and numerical foundation of the Finite Difference Time Domain method and the material properties needed when modeling a human body in FDTD. Then Coincident Phase Centers (CPCs) point sources models have been introduced which provide nearly the same accuracy at the distances as small as 3 unit cells from the phase center. Simultaneously, this model outperforms the usual sources in the near field when an arbitrary direction of the electric or magnetic dipole moment is required.

In Taiwan, non-point source (NPS) pollution is one of the major causes of the impairment of surface waters. NPS pollutants, which are associated with stormwater runoff from agricultural land uses can be quite diffuse and difficult to treat. The I-Liao Creek Basin, located in southern Taiwan, flows through approximately 90-km and drains towards the Kaoping River. It is one of the major sub-basin in the Kaoping River watershed, which is the largest and the most intensively used watershed in Taiwan. Field investigation results indicate that the main water pollution sources in the I-Liao Creek Basin are domestic wastewater and NPS pollutants from agricultural activities. In this study, an Integrated Watershed Management Model (IWMM) was applied for simulating the water quality in the I-Liao Creek watershed. The model includes a global atmosphere module, a land module, a human impact module, a canopy module, and a global ocean module. Those modules can be linked and managed by a graphic user-interface. The model was calibrated and verified with field data, and was used to investigate potential NPS pollution management plans. Moreover, the Storm Water Management Model (SWMM) was used to verify the accuracy of the simulated results of flow and water qualities. Results from this study show that geographical information system (GIS) is an important mean for land-use identification and waste load estimation in the catchment. Linking the information of land utilization with the NPS pollution simulation model may further provide essential information of pollution potential of NPS pollution for all sub-regions in the river basin. Results and experience obtained from this study will be helpful in designing the watershed management and NPS pollution control strategies for other similar river basins.

Polybrominated diphenyl ethers (PBDEs), flame retardants, have been applied to consumer goods, such as furniture, electrical devices, textiles, and appliances for decades. Due to their physico-chemical properties, PBDEs are semi-volatile and easily leach off the consumer good during aging, stress, or normal wear and tear of the good. Once airborne, they pose an environmental health threat because they can adsorb onto dust particles, soil, or other particulates that can be inhaled, ingested, or come into contact with the dermal layer. Additionally, PBDEs have a molecular structure similar to other persistent organic pollutants, such as polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins and furans. They are a health threat due to their endocrine-disrupting nature by affecting thyroid functioning, fertility, and child development. The purpose of the study is to measure selected PBDEs in a wastewater treatment plant (WWTP) that produces reclaimed water, such that a mass balance can be completed, and to compare this mass balance with theoretically expected concentrations. The mass balance includes the collection of samples from wastewater, sewage sludge, and air at points within the WWTP. The PBDEs examined are BDE-28, 47, 99, 100, 153, 154, and 183. The second part of the study will compare effluent concentrations to reclaimed water concentrations in order to examine the potential exposure (if any) of using reclaimed water. Influent concentration of mean (sum7)PBDE was found to be 49,117 pg/L and effluent concentration was 4,603 pg/L, illustrating a 91% removal rate of PBDEs during the wastewater treatment plant. Sludge samples contained the highest total concentrations of PBDEs with mean (sum7)PBDE ranging from 14.0 to 41.3 ug/kg dry weight. Air samples were highest at the post-aeration (248 pg/m3 mean (sum7)PBDE) step due to the use of highly oxygenated air assisting in the release and volatilization of the PBDEs. Sludge was found to carry the largest mass loading at 14.2 lb/day (sum7)PBDE. Of the total mass loading of PBDEs from the WWTP, sludge is responsible for 86.7%, followed by reclaimed water and effluent (11.7% and 1.6%, respectively). The mass loading from air was negligible with less than 0.01% contribution to the total mass loading. Whereas reclaimed water overall had higher PBDE congener mean concentrations than the effluent, the independent samples t-test found no statistically significant differences between the two groups. The results of this study can be used to improve the wastewater treatment process to reduce the impact of PBDEs being released into the environment by WWTPs, and to educate the public on utilizing reclaimed water in a safe and healthy manner.

Most managed turfgrass species require frequent inputs to maintain an acceptable level of quality. Among these inputs, nitrogen (N) fertilization is usually the most limiting in terms of growth and development. However, N fertilization is also linked to non-point source (NPS) pollution. White clover (WC) is known for its ability to provide N when mixed into stands of turfgrass, and does not pose a threat for NPS pollution. Two field studies were designed to investigate the effects of WC inclusion in stands of cool-season turfgrasses. In the first field study, three cultivation techniques were examined for establishment of WC into preexisting turfgrass stands at three different seasonal timings. Scalping during the summer was seen as providing the highest WC populations, although scalping treatments also caused the most initial damage to the turfgrass. In the second field study, mixed stands of turfgrass and WC were examined for response to several weeks of traffic simulations, with WC withstanding the traffic events. Additionally, a greenhouse study was implemented to examine the effects of several commercial broadleaf herbicides on two WC varieties. Only 2,4-D was shown to be safe for application to both WC varieties, although Microclover did show tolerance to quinclorac applications.

An evaluation of chemical parameters of surface waters proceed in the three small basin areas in Šumava Mountains, in the area of Svatý Tomáš highlands, during the year 2009: Bukový (woods), Mlýnský (semi{--}intensive and drained pasture, part of Pasečná village) and Horský stream (wetlands, woods, mowed meadows, a part of Svatý Tomáš village). The aim was to chart the three main periods during the year. The spring sampling (the 12th May) should illustrate the beginning of growing season with higher water flow rates. The summer sampling (the 21st July) is the period on the top of growing and touristic season, seasonal works in wood and especially in agriculture (grazing and mowing meadows). The last sampling (the 21st October) represents the season at the end of growing season, generally with the lowest flow rates in the stream, the end of touristic season and the end of full{--}area grazing. Already during the field research, involving the water sampling and conductivity measurement, there were some inflows with increased concentrations of dissolved solids found. Whereas in Bukový stream, as has been assumed, these inflows didn´t more or less occur, in Horský stream they had, relatively surprisingly but significantly, appeared immediately in headwater area. The elevated concentrations of dissolved solids occurred in Mlýnský stream in the whole area of basin, as has been assumed regarding to drainage and full{--}area grazing. One year monitoring proved the advantage of water quality evaluation using simple measurement of conductivity in field. High water conductivity in field was subsequently confirmed by laboratory analysis of selected ions. On the basis of identification of point sources of pollution, the recommendation improving present condition was suggested.