Innovations in Detecting and Modeling Dryland Hydrologic Changes

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Description
The hydrologic cycle in drylands is complex with large spatiotemporal variationsacross scales and is particularly vulnerable to changes in climate and land cover. To address the challenges posed by hydrologic changes, a synergistic approach that combines numerical models, ground and remotely sensed…

The hydrologic cycle in drylands is complex with large spatiotemporal variationsacross scales and is particularly vulnerable to changes in climate and land cover. To address the challenges posed by hydrologic changes, a synergistic approach that combines numerical models, ground and remotely sensed observations, and data analysis is crucial. This dissertation uses innovative detection and modeling techniques to assess key hydrologic variables in drylands, including irrigated water use, streamflow, and snowpack conditions, answering following research questions that also have broad societal implications: (1) What are the individual and combined effects of future climate and land use change on irrigation water use (IWU) in the Phoenix Metropolitan Area (PMA)?; (2) How can temporal changes in streamflow and the impacts of flash flooding be detected in dryland rivers?; and (3) What are the impacts of rainfall-snow partitioning on future snowpack and streamflow in the Colorado River Basin (CRB)? Firstly, I conducted a scenario modeling using the Variable Infiltration Capacity (VIC) model under future climate and land use change scenarios. Results showed that future IWU will change from -0.5% to +6.8% in the far future (2071-2100) relative to the historical period (1981-2010). Secondly, I employed CubeSat imagery to map streamflow presence in the Hassayampa River of Arizona, finding that the imaging capacity of CubeSats enabled the detection of ephemeral flow events using the surface reflectance of the near-infrared (NIR) band. Results showed that 12% of reaches were classified as intermittent, with the remaining as ephemeral. Finally, I implemented a physically-based rainfall-snow partitioning scheme in the VIC model that estimates snowfall fraction from the wet-bulb temperature using a sigmoid function. The new scheme predicts more significant declines in snowfall (-8 to -11%) and streamflow (-14 to -27%) by the end of the 21st century over the CRB, relative to historical conditions. Overall, this dissertation demonstrates how innovative technologies can enhance the understanding of dryland hydrologic changes and inform decision-making of water resources management. The findings offer important insights for policymakers, water managers, and researchers who seek to ensure water resources sustainability under the effects of climate and land use change.
Date Created
2023
Agent

Assessing Sustainability in the Water-Energy-Food Nexus

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Description
With less than seven years left to reach the ambitious targets of the United Nations' 2030 Sustainable Development Goals (SDGs), it is imperative to understand how the SDGs are operationalized in practice to support effective governance. One integrative approach, the…

With less than seven years left to reach the ambitious targets of the United Nations' 2030 Sustainable Development Goals (SDGs), it is imperative to understand how the SDGs are operationalized in practice to support effective governance. One integrative approach, the water, energy, and food (WEF) nexus, has been proposed to facilitate SDGs planning and implementation by incorporating synergies, co-benefits, and trade-offs. In this dissertation, I conduct three interrelated WEF nexus studies using a sustainability lens to develop new approaches and identify actionable measures to support the SDGs. The first paper is a systematic literature review (2015 – 2022) to investigate the extent to which WEF nexus research has generated actionable knowledge to achieve the SDGs. The findings show that the WEF nexus literature explicitly considering the SDGs mainly focuses on governance and environmental protection, with fewer studies focusing on target populations and affordability. In the second paper, I reframed the water quality concerns using a nexus and systems thinking approach in a FEW nexus hotspot, the Rio Negro Basin (RNB) in Uruguay. While Uruguay is committed to the 2030 Agenda for Sustainable Development, sustainability challenges endure in managing synergies and trade-offs, resulting in strategy setbacks for the sustainable development of food, land, water, and oceans. Reframing the water quality problem facilitated the identification of potential alternative intervention points to support local problem-solving capacity. In the third paper, I conducted semi-structured interviews and examined the meeting transcripts of the RNB Commission to understand local perspectives about how the activities and initiatives taking place in the basin enhance or diminish the overall sustainability. Sustainability criteria for river basin planning and management were operationalized through qualitative appraisal questions. The case of the RNB illustrates the challenges of coordinating the national development agenda to local livelihood. This dissertation advances the WEF nexus and sustainability science literature by shedding light on the implications of the research trend to support the SDGs, as well as reframing and appraising a persistent water quality problem to support sustainable development.
Date Created
2023
Agent

Colorado River Basin Hydrology under Future Climate and Land Cover Changes

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Description
Accelerated climate and land use land cover (LULC) changes are anticipated to significantly impact water resources in the Colorado River Basin (CRB), a major freshwater source in the southwestern U.S. The need for actionable information from hydrologic research is growing…

Accelerated climate and land use land cover (LULC) changes are anticipated to significantly impact water resources in the Colorado River Basin (CRB), a major freshwater source in the southwestern U.S. The need for actionable information from hydrologic research is growing rapidly, given considerable uncertainties. For instance, it is unclear if the predicted high degree of interannual precipitation variability across the basin could overwhelm the impacts of future warming and how this might vary in space. Climate change will also intensify forest disturbances (wildfire, mortality, thinning), which can significantly impact water resources. These impacts are not constrained, given findings of mixed post-disturbance hydrologic responses. Process-based models like the Variable Infiltration Capacity (VIC) platform can quantitatively predict hydrologic behaviors of these complex systems. However, barriers limit their effectiveness to inform decision making: (1) simulations generate enormous data volumes, (2) outputs are inaccessible to managers, and (3) modeling is not transparent. I designed a stakeholder engagement and VIC modeling process to overcome these challenges, and developed a web-based tool, VIC-Explorer, to “open the black box” of my efforts. Meteorological data was from downscaled historical (1950-2005) and future projections (2006-2099) of eight climate models that best represent climatology under low- and high- emissions. I used two modeling methods: (1) a “top-down” approach to assess an “envelope of hydrologic possibility” under the 16 climate futures; and (2) a “bottom-up” evaluation of hydrology in two climates from the ensemble representing “Hot/Dry” and “Warm/Wet” futures. For the latter assessment, I modified land cover using projections of a LULC model and applied more drastic forest disturbances. I consulted water managers to expand the legitimacy of the research. Results showed Far-Future (2066-2095) basin-wide mean annual streamflow decline (relative to 1976-2005; ensemble median trends of -5% to -25%), attributed to warming that diminished spring snowfall and melt and year-round increased soil evaporation from the Upper Basin, and overall precipitation declines in the Lower Basin. Forest disturbances partially offset warming effects (basin-wide mean annual streamflow up to 12% larger than without disturbance). Results are available via VIC-Explorer, which includes documentation and guided analyses to ensure findings are interpreted appropriately for decision-making.
Date Created
2022
Agent

Is Resilience Achieved in Colorado River Recovery Programs? A Complex Social-Ecological Systems Approach

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Description
Globally, rivers are being heavily dammed and over-utilized to the point where water shortages are starting to occur. This problem is magnified in arid and semi-arid regions where climate change, growing populations, intensive agriculture and urbanization have created tremendous pressures…

Globally, rivers are being heavily dammed and over-utilized to the point where water shortages are starting to occur. This problem is magnified in arid and semi-arid regions where climate change, growing populations, intensive agriculture and urbanization have created tremendous pressures on existing river systems. Regulatory incentives have been enacted in recent decades that have spurred river restoration programs in the United States. But what kind of governance does river restoration require that is different from allocative institutional set-ups? Are these recovery programs succeeding in restoring ecological health and resilience of the rivers? Do the programs contribute to social-ecological resilience of the river systems more broadly? This study aims to tackle these key questions for two Colorado River sub-basin recovery programs (one in the Upper Basin and one in the Lower Basin) through utilization of different frameworks and methodologies for each. Organizational resilience to institutional and biophysical disturbances varies, with the Upper Basin program being more resilient than the Lower Basin program. Ecological resilience as measured by beta diversity (for the Upper Basin) was a factor of the level of hydrological and technological interventions rather than an occurrence of the natural flow regime. This points to the fact that in a highly-dampened and managed system like the Colorado River, the dampened flow regime alone is not a significant factor in maintaining community diversity and ecological health. A broad-scale social-ecological analysis supports the finding that the natural feedback between social and ecological elements is broken and recovery efforts are more an attempt at resuscitating the river system to maintain a semblance of historic levels of fish populations and aquatic processes. Adaptive management pathways for the future need to address and build pathways to transformability into recovery planning to achieve resilience for the river system.
Date Created
2021
Agent

Understanding Collaborative Governance of the Food-Energy-Water Nexus: The Cases of Phoenix and Cape Town

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Description
The food-energy-water (FEW) nexus refers to the interactions, trade-offs, and relationships between the three resources and their related governance sectors. Given the significant interdependencies, decisions made in one sector can affect the other two; thus, integrated governance can reduce unintended…

The food-energy-water (FEW) nexus refers to the interactions, trade-offs, and relationships between the three resources and their related governance sectors. Given the significant interdependencies, decisions made in one sector can affect the other two; thus, integrated governance can reduce unintended consequences and lead towards increased resource security and sustainability. Despite the known benefits, many governance decisions continue to be made in “silos,” where stakeholders do not coordinate across sectoral boundaries. Scholars have begun to identify barriers to the implementation of integrated FEW nexus governance, yet there is still minimal understanding of the reasons why these barriers exist and no theoretical framework for evaluating or assessing FEW nexus governance. Integrating the theory of collaborative governance with the concept of the FEW nexus provides an opportunity to better understand the barriers to and structures of FEW nexus governance and to propose solutions for increased collaborative FEW nexus governance in practice. To investigate this governance system, I examined the collaborative governance of the FEW nexus in the context of extreme urban water challenges in two urban case cities: Phoenix, Arizona, USA and Cape Town, South Africa. First, I performed a media analysis of the 2018 Cape Town water crisis to understand the impact of the water crisis on the FEW nexus resource system and the collaborative governance employed to respond to that crisis. Second, I conducted a systematic case study of FEW nexus governance in Phoenix, Arizona to understand barriers to collaborative governance implementation in the system and to identify opportunities to overcome these barriers. Finally, I presented a framework of indicators to assess the collaborative governance of the local FEW nexus. This dissertation will advance the sustainability literature by moving the concept of FEW nexus governance from theory and conceptualization towards operationalization and measurement.
Date Created
2021
Agent

Mechanisms of social vulnerability to environmental hazards

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Description

Environmental hazards and disaster researchers have demonstrated strong associations between sociodemographic indicators, such as age and socio-economic status (SES), and hazard exposures and health outcomes for individuals and in certain communities. At the same time, behavioral health and risk communications…

Environmental hazards and disaster researchers have demonstrated strong associations between sociodemographic indicators, such as age and socio-economic status (SES), and hazard exposures and health outcomes for individuals and in certain communities. At the same time, behavioral health and risk communications research has examined how individual psychology influences adaptive strategies and behaviors in the face of hazards. However, at present, we do not understand the explanatory mechanisms that explain relationships between larger scale social structure, individual psychology, and specific behaviors that may attenuate or amplify risk. Extreme heat presents growing risks in a rapidly warming and urbanizing world. This dissertation examines the social and behavioral mechanisms that may explain inequitable health outcomes from exposure to concurrent extreme heat and electrical power failure in Phoenix, AZ and extreme heat in Detroit, MI. Exploratory analysis of 163 surveys in Phoenix, AZ showed that age, gender, and respondent’s racialized group identity did not relate to thermal discomfort and self-reported heat illness, which were only predicted by SES (StdB = -0.52, p < 0.01). Of the explanatory mechanisms tested in the study, only relative air conditioning intensity and thermal discomfort explained self-reported heat illness. Thermal discomfort was tested as both a mechanism and outcome measure. Content analysis of 40 semi-structured interviews in Phoenix, AZ revealed that social vulnerability was associated with an increase in perceived hazard severity (StdB = 0.44, p < 0.01), a decrease in perceived adaptation efficacy (StdB = -0.38, p = 0.02), and an indirect increase (through adaptive efficacy) in maladaptive intentions (StdB = 0.18, p = 0.01). Structural equation modeling of 244 surveys in Phoenix, AZ and Detroit, MI revealed that relationships between previous heat illness experience, perceived heat risk, and adaptive intentions were significantly moderated by adaptive capacity: high adaptive capacity households were more likely to undertake adaptive behaviors, and those decisions were more heavily influenced by risk perceptions and previous experiences. However, high adaptive capacity households had lower risk perceptions and fewer heat illness experiences than low adaptive capacity households. A better understanding of the mechanisms that produce social vulnerability can facilitate more salient risk messaging and more targeted public health interventions. For example, public health risk messaging that provides information on the efficacy of specific adaptations may be more likely to motivate self-protective action, and ultimately protect populations.

Date Created
2019
Agent

Sustainability principles and the future of Phoenix, Arizona: framing the Salt River's urban waterway redevelopment

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Description
As urban populations rapidly increase in an era of climate change and multiple social and environmental uncertainties, scientists and governments are cultivating knowledge and solutions for the sustainable growth and maintenance of cities. Although substantial literature focuses on urban water…

As urban populations rapidly increase in an era of climate change and multiple social and environmental uncertainties, scientists and governments are cultivating knowledge and solutions for the sustainable growth and maintenance of cities. Although substantial literature focuses on urban water resource management related to both human and ecological sustainability, few studies assess the unique role of waterway restorations to bridge anthropocentric and ecological concerns in urban environments. To address this gap, my study addressed if well-established sustainability principles are evoked during the nascent discourse of recently proposed urban waterway developments along over fifty miles of Arizona’s Salt River. In this study, a deductive content analysis is used to illuminate the emergence of sustainability principles, the framing of the redevelopment, and to illuminate macro-environmental discourses. Three sustainability principles dominated the discourse: civility and democratic governance; livelihood sufficiency and opportunity; and social-ecological system integrity. These three principles connected to three macro-discourses: economic rationalism; democratic pragmatism; and ecological modernity. These results hold implications for policy and theory and inform urban development processes for improvements to sustainability. As continued densification, in-fill and rapid urbanization continues in the 21st century, more cities are looking to reconstruct urban riverways. Therefore, the emergent sustainability discourse regarding potential revitalizations along Arizona’s Salt River is a manifestation of how waterways are perceived, valued, and essential to urban environments for anthropocentric and ecological needs.
Date Created
2019
Agent

Quenching our thirst for future knowledge: participatory scenario construction and sustainable water governance in a desert city

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Description
Transformational sustainability science demands that stakeholders and researchers consider the needs and values of future generations in pursuit of solutions to sustainability problems. This dissertation research focuses on the real-world problem of unsustainable water governance in the Phoenix region of…

Transformational sustainability science demands that stakeholders and researchers consider the needs and values of future generations in pursuit of solutions to sustainability problems. This dissertation research focuses on the real-world problem of unsustainable water governance in the Phoenix region of Central Arizona. A sustainability transition is the local water system is necessary to overcome sustainability challenges and scenarios can be used to explore plausible and desirable futures to inform a transition, but this requires some methodological refinements. This dissertation refines scenario methodology to generate water governance scenarios for metropolitan Phoenix that: (i) feature enhanced stakeholder participation; (ii) incorporate normative values and preferences; (iii) focus on governance actors and their activities; and (iv) meet an expanded set of quality criteria. The first study in the dissertation analyzes and evaluates participatory climate change scenarios to provide recommendations for the construction and use of scenarios that advance climate adaptation and mitigation efforts. The second study proposes and tests a set of plausibility indications to substantiate or evaluate claims that scenarios and future projections could become reality, helping to establish the legitimacy of radically different or transformative scenarios among an extended peer community. The case study of water governance begins with the third study, which includes a current state analysis and sustainability appraisal of the Phoenix-area water system. This is followed by a fourth study which surveys Phoenix-area water decision-makers to better understand water-related preferences for use in scenario construction. The fifth and final study applies a multi-method approach to construct future scenarios of water governance in metropolitan Phoenix in 2030 using stakeholder preferences, among other normative frames, and testing systemic impacts with WaterSim 5.0, a dynamic simulation model of water in the region. The scenarios are boundary objects around which stakeholders can weigh tradeoffs, set priorities and reflect on impacts of water-related activities, broadening policy dialogues around water governance in central Arizona. Together the five studies advance transformational sustainability research by refining methods to engage stakeholders in crafting futures that define how individuals and institutions should operate in transformed and sustainable systems.
Date Created
2014
Agent

Antecedents of effective environmental management: a test of the value-belief-norm theory

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Description
The purpose of this quantitative study is to test the validity of a behavioral theory, value-belief-norm theory (Stern, 2000), in the context of environmental hotel management. The lack of theoretical consideration in previous studies on environmental attitudes of hotel/resort managers…

The purpose of this quantitative study is to test the validity of a behavioral theory, value-belief-norm theory (Stern, 2000), in the context of environmental hotel management. The lack of theoretical consideration in previous studies on environmental attitudes of hotel/resort managers warrants an investigation of a theory with the potential to better explain behaviors that support the goals of environment management systems. The goal of this research was to document the values, beliefs, personal norms, and environmental management support behaviors of managers in a hospitality setting. Data were collected from a sample of hotel and resort managers in the Phoenix metropolitan area by using a survey of well-documented items from previous research on the theory. Results suggest the value-belief-norm theory is successful in explaining environmental management support behaviors. Implications for practitioners as well as researchers are discussed.
Date Created
2011
Agent
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