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Graduate Theses & Dissertations

: Effects of Intensive Agriculture on Stream Nutrient Export in East-Central Ontario, Canada; Recent agricultural land use change in east-central Ontario, including the expansion of intensive agriculture (corn and soybean crops) and tile drainage (TD) infrastructure, may alter the fluxes of both phosphorus (P) and nitrogen (N) to the Lower Great Lakes. Through intensive monitoring of several sub-watersheds that encompassed a range of row crop and TD extents, this study examined differences in stream N and P concentrations both seasonally and during variable flow conditions, to better understand land use/land cover (LULC) relationships with nutrient export. There was no clear relationship between total P (TP; concentration or export) and agricultural LULC, and instead, TP delivery was highly sensitive to flow events, and TP concentrations (especially particulate P; PP) were significantly higher during event flow compared with baseflow. In contrast, the dissolved fraction of P (total dissolved P; TDP) and dissolved nitrogen as nitrate (NO3-N) were not sensitive to flow, but were instead positively related to row crop agriculture, and associations between NO3-N concentrations/export and tile-drained row crop area were particularly strong (concentration r2 = 0.93; export r2 = 0.88). Regression relationships showed that with every 10% increase in row crop area in watersheds, NO3-N and TDP flow-weighted concentrations increased by 0.34 mg/L and 1.5 µg/L, respectively. As well, the same 10% increase in row crop agriculture translated to an increase of NO3-N export of as much as 130 kg/km2. Geospatial records of TD are incomplete in east-central Ontario, which presents challenges for evaluating the contribution of TD to nutrient export. Understanding the response of nutrients to changes in agriculture and agricultural practices is an integral part of watershed management as rapid changes in both urban and agricultural LULC continue to put pressure on water quality in the Lower Great Lakes. Author Keywords: East-Central Ontario, Nutrient Export, Row crops, Streams, Tile Drainage, Water Quality

: AN INTEGRATED APPROACH TO WASTEWATER MANAGEMENT AND REUSE IN JORDAN; This research explores the obstacles Jordan is facing regarding the sustainable treatment and reuse of wastewater in the agricultural sector. It assesses the technical, socio-cultural, and political aspects of decision-making around water and wastewater management in Jordan by focusing on a case study involving wastewater usage in the Jordan Valley. It includes a literature review and interviews with representatives of key stakeholders. While at one level wastewater treatment is a technical process with technological solutions, a nuanced understanding of the non-technical challenges facing the wastewater treatment sector in Jordan is necessary. These challenges are inherently embedded in and contextualized by a series of historical, complex and dynamic political and socio-cultural issues involving stakeholders at local and national levels. Only through an interdisciplinary approach with real stakeholder engagement will meaningful solutions to these challenges be developed and implemented, and at least a portion of Jordan's water needs be meaningfully addressed. Author Keywords: Agriculture, Jordan Valley, Political challenges, Sociocultural challenges, Technical challenges, wastewater management

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