<p> Water quality monitoring is essential to human health, ecological stability, and scientific research but remains hampered by Large, expensive, inflexible, and sometimes unreliable systems. To address these problems, an open source, flexible, and inexpensive sonde was designed and created capable of meeting research needs, along with a buoy system to support its use. A new optical UV based sensor was created to help measure phosphate ion levels. Together these technologies could further ecological research and help safeguard ecosystems.</p>

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abstract: Uncertainty is inherent in predictive decision-making, both with respect to forecasting plausible future conditions based on a historic record, and with respect to backcasting likely upstream states from downstream observations. In the first chapter, I evaluated the status of current water resources management policy in the United States (U.S.) with respect to its integration of projective uncertainty into state-level flooding, drought, supply and demand, and climate guidance. I found uncertainty largely absent and discussed only qualitatively rather than quantitatively. In the second chapter, I turned to uncertainty in the interpretation of downstream observations as indicators of upstream behaviors in the field of Wastewater-Based Epidemiology (WBE), which has made possible the near real-time, yet anonymous, monitoring of public health via measurements of biomarkers excreted to wastewater. I found globally, seasonality of air and soil temperature causes biomarker degradation to vary up to 13-fold over the course of a year, constituting part of the background processes WBE must address, or detrend, prior to decision-making. To determine whether the seasonal change in degradation rates was introducing previously unaccounted for uncertainty with respect to differences in observed summertime and winter-time populations, I evaluated demographic indicators recorded by the Census Bureau for correlation with their distance from all major wastewater treatment plants across the U.S. The analysis identified statistically significant correlation for household income, education attainment, unemployment, military service, and the absence of health insurance. Finally, the model was applied to a city-wide case study to test whether temperature could explain some of the trends observed in monthly observations of two opiate compounds. Modeling suggests some of the monthly changes were attributed to natural temperature fluctuation rather than to trends in the substances’ consumption, and that uncertainty regarding discharge location can dominate even relative observed differences in opiate detections. In summary, my work has found temperature an important modulator of WBE results, influencing both the type of populations observed and the likelihood of upstream behaviors disproportionally magnified or obscured, particularly for the more labile biomarkers. There exists significant potential for improving the understanding of empirical observations via numerical modeling and the application of spatial analysis tools. / Dissertation/Thesis / Doctoral Dissertation Biological Design 2019

A thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Johannesburg, 2019 / Water resource systems management entails the coordination of hydrologic, infrastructural and human activities to plan, develop and supply water efficiently and sustainably. Hydrologic and human behaviour involve high levels of uncertainty and therefore pose unique challenges to water management. In reservoir yield and operation analysis, hydrologic uncertainties are usually incorporated in risk analysis using stochastically generated data but the impacts of human behaviour, although significant, are typically not incorporated. This study was therefore inspired by the need to quantitatively incorporate the impact of human behaviour into reservoir system performance thereby adding value to reservoir operational decision making. Unauthorised water abstraction is a significant human behaviour‐related activity and was therefore selected for this study. A socio‐hydrological model that simulates, couples and dynamically co‐evolves reservoir operation and human behaviour to assess the impact of unauthorised water abstractions on reservoir yield and operation was developed. The model quantitatively and stochastically relates fourstate drivers; hydrological state, users’ compliance, management competence and reservoir performance. Users’ compliance and management competence were modelled statistically by a 3‐parameter skew‐normal distribution and the propensity to unauthorised water abstraction (risk perception) was modelled as a function of users’ compliance, management competence and the hydrological state. The occurrence of unauthorised water abstraction was modelled stochastically by relating a sigmoidal function of risk perception to management competence. To assess the impact of human behaviour, nine scenarios derived from the different combinations of 3 categories of users’ compliance and management competence were developed and tested. The model was applied at a monthly time step to 2 hypothetical but realistic reservoir systems that were based on 90 years of hydrology and configuration of the Elands and the Olifants River reservoir systems in South Africa. Reservoir operation for maximizing yield was optimized by applying a simulation‐optimization approach that used 3 reservoir operating rule curves defined using trigonometric and simple linear functions. Shuffled complex evolution (SCE‐UA) was used for optimisation. The SCE‐UA was effective for the optimisation of the two reservoir systems when simple linear operating rules were applied. When trigonometric rule curves were applied, the SCE‐UA optimized the Elands system effectively but repeatedly terminated at a local optimum with 35% less yield for the larger Olifants system. It was therefore decided to mainly use the results from the linear rule curves to assess the effect of human behaviour on the performance of the two systems. Realistic time series of unauthorised water abstractions whose severity increased as users’ compliance and management competence declined were obtained. The losses in average yield for varying combinations of users’ compliance and management competence ranged from 2.3 to 9.2% and 5.3 to 11.5% for the Elands and Olifants systems respectively. The overall average loss in yield for all the nine scenarios were 5.8% and 8.9% for the Elands and Olifants River systems respectively. The losses in yield in individual years, however, varied considerably and during the drought years of the 90 year simulation period, they were much higher than the average losses. In one year, a 55% reduction in yield resulted from the scenario with the most adverse human behaviour. Optimised reservoir operating rule curves became more restrictive and lower reservoir storage trajectories were obtained as human behaviour declined. The modelling, therefore, revealed that yield reduced as human behaviour deteriorated and the losses obtained were reasonably close to the reported annual water loss due to unlawful uses of 6.4% in South Africa. The sensitive nature of the subject of study makes model verification on real‐life systems challenging. However, the research shows that practical reservoir system modelling that quantitatively incorporate the impact of human behaviour is a future possibility. / PH2020

Bibliography: pages 138-151. / Water resource decision making in Greater Cape Town is characterised by numerous, often conflicting goals. Among these are ensuring engineering feasibility and flexibility of supply, maximising water yield, minimising costs and minimising negative environmental and social impacts. Furthermore, in the face of ongoing development, decisions on future water supply options can be expected to increase in complexity along with the potential for conflict as natural resources become more scarce. In the present political climate, the need to transform public sector decision making into a democratic and transparent process has been recognised. Stakeholder groups need to be satisfied that their interests are taken into account in decision making and that decision makers are accountable for their actions. This thesis argues the case for the use of a formal framework to improve future decision making between water supply options in light of the above goals. After debating which type of framework would be most appropriate, the possible workings of a future system are briefly outlined.

Green stormwater infrastructure (GSI) is implemented in urban landscapes to manage stormwater quantity and quality. Bioretention is an infiltration-based GSI strategy and demonstrates variable performance for total nitrogen (TN) removal. Internal water storage (IWS) is a sub-grade design feature that uses an underdrain with an elevated outlet to force a submerged layer. When a carbon source is present, often woodchips, IWS facilitates denitrification—the microbial reduction of nitrate (NO3-) to nitrogen gas (N2). This work considers the impact of IWS underdrain configuration, geometry, and IWS media on hydraulics, TN, and NO3- removal to enhance IWS design. To explore the impact of underdrain height, three laboratory columns with underdrains located at the bottom (0 cm), middle (15 cm), and top (30 cm) of a gravel-woodchip IWS were coupled with USGS VS2DRTI simulations. For narrow IWS geometries, width to depth (w/d) ratio < 1, hydraulic efficiency (ev) decreased from 1.0 to 0.76 as underdrain height increased from the bottom (0 cm) to top (30 cm). Changes in ev were attributed to the presence of immobile (low flow) zones below raised underdrains that limited solute transport. The presence of immobile zones impacted NO3- removal efficiency which decreased from 63% (bottom underdrain) to 32% (top underdrain) for a hydraulic loading rate (HLR) of 2.5 cm/h. However, simulated scenarios beyond the lab scale revealed ev varied less than 10% for IWS w/d ratios > 1 and indicated flow dynamics observed for narrow columns do not always translate to wider field systems. Under transient flow conditions, minimizing effluent NO¬3- concentrations and loads ranked least to greatest in the order bottom > middle > top underdrain configurations and dual isotopes in NO3- confirmed the presence of denitrification in mobile zones. Laboratory columns with bottom underdrain configurations considered three IWS media compositions of gravel, gravel-woodchip, and gravel-woodchip-biochar. Synthetic stormwater was modified to include dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and trace organic nitrogen compounds. Under continuous flow conditions, NO3- removal efficiency ranked in the order gravel-woodchip (78%) > gravel-woodchip-biochar (61%) > gravel (-10%) for a HLR of 2.5 cm/h. During antecedent dry periods, the gravel-woodchip-biochar and gravel-woodchip IWS removed NO3- within 18 hours following a transient event. However, the presence of biochar resulted in ammonium (NH4+) generation and effluent concentrations exceeded levels toxic to aquatic life. High-frequency field monitoring of an IWS with a raised underdrain was performed for eight storms over ten months. IWS nitrogen concentrations during storm events revealed that peak TN concentration generally occurred within the first hour during the rising limb of the IWS water level and that TN was likely exported from the system in the form of DON and NO3-. Additionally, NH4+ washout from unsaturated soil occurred during February through May and was attributed to sodium dispersion due to road salt application. This work coupled laboratory columns, modeling, and field studies to address the complexities of nitrogen management in bioretention as impacted by IWS underdrain height, geometry, ev, media selection, absorbent amendments, and seasonal patterns. When approaching IWS design for water quality enhancements, practitioners are encouraged to consider all these variables but recognize that the desired TN removal will not be achieved in some cases. / Environmental Engineering

A water characteristic and hydrogeologic study was conducted at the site of a proposed lignite mine in Kemper and Lauderdale Counties, Mississippi. The goal of the project was to collect background information on the conditions of subsurface and surface water resources, prior to the development of the proposed mine. Every water well, spring, stream, and pond within the project area was sampled, tested for specific variables, and analyzed. Measurements of pH, temperature, dissolved oxygen, turbidity, and specific conductivity were collected. Subsurface water levels were measured at accessible water wells. Spring and stream flow rates were gauged by measuring the velocity of the flow and the cross sectional area. Fourteen surface water sites were monitored, as well as fluctuations during base, normal, and highlow events. The data determined that streams are flashy and overall good quality. The project area possesses limited ground water resources that are of good quality.

Daily pan evaporation data are poorly collected. This thesis uses different methods to correct these inadequate data, and make them usuable for many scientific purposes. Nine Southeastern region states with a total of 83 evaporation sites were chosen to represent the study region. These data were corrected to be serially complete and homogeneously sound for the entire stations' period of record. After the data corrections were made, temporal and spatial analyses were completed. These analyses help display the functionality of these corrected data. This study provides an enhanced understanding of the evaporation regime of the Southeastern region and makes an enormous amout of usable data available. These data sets are contributed to the literature for use in future research, and are distributed to all State and Regional Climate Centers in the Southeastern region.

Yes / Water governance is a widely-used but ill-defined term. Our objective throughout this seminar series has been to analyse what it does mean and to question the consensus that seems to attach to it. In this paper for the final seminar I discuss what governance is not, I suggest what it is and I consider some propositions and issues that seem to have emerged from our meetings. In doing this, I appreciate that governance can mean different things to different people, but I suggest that, used in a specific way, it is a concept with particular value and significance for water development. / ESRC

Yes / The concept of water governance is a firmly established part of the consensus on international water development, and has become a constant theme in the policy processes we are discussing in this seminar. Originating in its present format at about the time of the second World Water Forum in 2002, it was specifically restated at the International Conference on Freshwater in Bonn, 2001 (¿the essential key is stronger, better performing governance arrangements¿), and it featured prominently in the outputs from the Third World Water Forum in Kyoto, 2003. In the Alternative Water Forum, held here in Bradford just after the Kyoto event, we encouraged participants to analyse and critically debate the underlying ideas, In this paper I want to encourage this continuing analysis and debate. Like many of the issues we shall be discussing over the next couple of days, I believe it repays closer consideration, and that it encompasses a set of important ideas which must not be lost in constant re-iteration of a general theme. / ESRC