The North American Monsoon System (NAMS) is a significant weather and climate phenomenon that brings critical rainfall to the southwestern United States and northwestern Mexico. As a result of the North American Monsoon Experiment, and research efforts surrounding the field campaign, the understanding of the NAMS has increased considerably over the last 15 years. In addition questions concerning potential flash flood causing mechanisms of the NAMS have not been thoroughly investigated. This dissertation is comprised of two papers that collectively address the aspects of the literary understanding of the NAMS as we know it today and conduct an investigation into the complex interactions between various weather systems that may influence the NAMS. In the first paper, a review of the major research of the NAMS literature since the last comprehensive review 15 years ago is conducted. The results of his review are assessed for where our understanding has been improved and where future research needs to be guided for purposes of the second paper. Based upon the results from the literature review, the second paper focuses on identification of inverted troughs and gulf surges based upon lower- and mid-level atmospheric parameters for purposes of assessing the impacts on National Weather Service Storm Report flash flood dates. This research contributes to the synthesis of the current knowledge of the NAMS in general and to the specific regional impacts that do occur during periods of heavy precipitation over the NAMS region for purposes of improving meteorological predictability of flash flooding. The results can (1) gauge our understanding of the NAMS literature to date and (2) improve meteorological forecasts through the recognition of synoptic and sub-synoptic patterns related to the NAMS that are most likely to cause flash floods.

Progress in human development is threatened by the complexities of global environmental change - a defining challenge of our time. Appropriate societal responses are needed to address disturbances and increasing vulnerability of social-ecological systems. This changing context calls current development thinking into question and requires new approaches, policies, and tools to cope with growing uncertainty. With a focus on capacities instead of vulnerabilities, an approach is needed emphasizing the role of communities in planning interventions and strengthening community resilience. This research draws on vulnerability, social-ecological systems and drylands development theory to advance an integrated understanding of resilience at community level and its role towards sustainable development. To develop a general approach for development actors to characterize a community's resilience and plan locally targeted interventions is the overall objective of this research. A participatory approach towards defining and assessing community resilience forms the basis, as it is assumed this would enable development actors to more efficiently address development concerns and empower communities to strengthen their resilience. Underlying factors that determine community resilience in selected dryland communities in Tigray, northeastern Ethiopia are identified. Here, most of the population depends on subsistence agriculture, while food insecurity and poverty persist despite concerted regional development efforts. This research compares and consolidates local perceptions of determinants of community resilience that form the basis for guidelines towards a methodological framework for determining levels of community resilience in Tigray. The guidelines were used to compare levels of community resilience of communities, with implications for operationalizing community resilience in the context of drylands development practice. Findings reflect the importance of recognizing that resilience is not about maintaining a status quo, but about addressing how societies can develop in a changing environment. Prominence of resilience thinking can promote a development practice better suited to address the challenges and opportunities that changes create for poor dryland communities. Resilience thinking does not provide quick solutions, but contributes a long-term, multi-dimensional perspective of building capacities for improved responses to current needs and future change. Resilience is not a solution in itself but can contribute towards developing more resilient trajectories for drylands development.

Rural households in the West African Sahel have developed livelihood systems that allow them to survive in one of the most challenging social-ecological systems on Earth. These households have experienced environmental shocks including droughts, floods, and extreme heat for hundreds of years, and have well-established coping and adaptation mechanisms that allow them to recover from all but the most severe shocks. Climate change, particularly increased climatic variability, may stress Sahelian livelihood systems to the point that households must deploy a new set of coping and adaptation strategies in order to survive. This research, conducted as three interrelated mixed-method studies, explores the coping and adaptation strategies used by Tuareg transhumant pastoralists in Niger starting with the deep drought of 1968-1974.The first study involves rural households in the Tahoua Region of central Niger. These households have adapted to climate change and other livelihood stressors primarily by diversifying their assets, utilizing new technologies, and reducing the length of their annual transhumance. While there are donor-funded programs designed to assist rural households with adaptation to climate change, the households in this study have not been the beneficiaries of such programs. The second study attempts to disentangle climate shocks from other factors driving rural-urban migration while also exploring which households migrate to urban areas, and why. Climate change is perceived as the main factor driving rural-urban migration, as well as other livelihood changes. Household-level preferences, management skills, and luck played a greater role that asset endowments in determining which households would migrate to urban areas. The third study focused on livelihood strategies of households that had migrated to, and settled in, urban areas. These households worked hard to maintain social capital with their rural kin while also building social capital in their new urban environment. Social capital with expatriates and urban elites was an important element of urban households' asset endowment. Urbanized households possess significantly fewer livestock than their rural counterparts, and struggle to manage the cash earned from relatively low-paying wage labor. These three studies demonstrate that pastoralists perceive climate change as a significant driver of changes in livelihood strategies. Pastoralists' perceptions of climate change broadly match climate data. Furthermore, pastoralists, with little to no assistance from the state or development organizations, are successfully adapting to climate change in ways that are likely to increase their resilience to future climate shocks.

The electricity sector around the world is significantly changing towards the adoption of cleaner energy sources and its implementation through distributed generation technologies. The need to expand rural electrification to reduce energy poverty and the trends in decentralizing power generation are becoming major drivers of change. In Mexico, there are very few comprehensive studies on energy use and its impact on rural livelihoods. Energy studies in the development literature tend to analyze livelihoods that do not have access to modern energy services, and do not take into account that many rural communities, although connected to the grid, still may be considered energy poor. This research presents findings of current livelihood conditions of three rural communities in the Mexican state of Chihuahua, in the context of livelihood diversification and energy poverty. This paper also presents a feasibility study for the development of a community energy model that will fulfill energy and vegetable intake requirements for each community analyzed. Results show that these communities can potentially improve their livelihood conditions through the implementation of what this research calls a Community Integrated Sustainable Energy (CISE) model by reducing energy poverty and food insecurity. By adopting a CISE model, communities will become healthier by becoming supporters of energy conservation and energy efficiency strategies. The adoption of this community energy model will also encourage climate change mitigation by increasing resilience to vulnerable communities through enhancing food and energy security. The aim of this research is to inform stakeholders (including policy makers, urban planners, and community members themselves) of the current status of Chihuahua's communities and to start a dialogue in Mexico about engaging in a community-led, clean energy project that would generate electricity for those communities while preserving rural livelihoods.

In drylands, it is essential to maximize the coupling of social and ecological systems in order to achieve sustainability, particularly in human dominated landscapes such as cities. The enhanced use of greenspace in cities in drylands provides unique opportunities to maximize the coupling of social and ecological systems. It maintains the functioning of ecological systems while involving civil society in the conservation of biodiversity and improving human wellbeing in urban settings. The provision and access to greenspace in cities is determined by neighborhood design. The access for the human use of greenspace can be enhanced through walkability, or the characteristics of the built environment that influence physical activity. Walkable neighborhoods that provide access to greenspace can be catalysts for activity and health and have the potential to increase the level of conservation support in urban residents. The purpose of this research is to look for wellbeing and conservation synergies between walkable neighborhoods and the enhanced use of greenspace. To accomplish this research, first we assess walkability in the built environment through an interdisciplinary literature review that integrates the findings on walkability from several research domains. We create a conceptual framework that organizes the neighborhood design elements that influence physical activity into nine walkability categories: connectivity, land-use, density, traffic safety, surveillance, parking, experience, greenspace, and community. We call this the Walkability Framework. This analysis allows us to identify gaps and strengths of walkability in the Leadership for Energy and Environmental Design for Neighborhood Development (LEED-ND) certification system. After a quantitative and qualitative analysis, we propose an enhanced version for walkability that we call LEED-NDW+ (walkability plus). The next step is to test if the Walkability Framework can be used as a model to measure the interactions between the built environment and physical activity. We accomplish this through the use of a questionnaire (N=486) that captures the perceptions, attitudes and behaviors of residents in Tucson, Arizona. Significant correlations between all the walkability categories and physical activity support the use of the framework as a model. We call this the Walkability Model. The final stage of this research uses the Walkability Model to evaluate walkability in four neighborhood design types in Tucson that include traditional development, suburban development, enclosed community, and cluster housing. We then look for wellbeing and conservation synergies between walkable neighborhoods and the enhanced use of greenspace. Results from this study suggest that neighborhoods with a high level of walkability have the potential to enhance the use of greenspace, which in turn provide important wellbeing and conservation synergies that can contribute to healthier communities and increase the support for conservation of biodiversity within and beyond cities. The enhanced use of greenspace maximizes the coupling of social and ecological systems in cities in drylands, which increases resilience in the face of climate change.

Most of dengue transmission occurs in tropical and subtropical zones. As a result, studies on the dynamics of dengue transmission are principally focused in these areas. Less is known about the dynamics of dengue transmission and the interplay of social and climatic determinants in arid regions located at the fringe of transmission zones. This dissertation uses surveillance data from the state of Sonora, an arid region in northern Mexico, to examine three specific aims: 1) to assess relationships among social and climatic factors utilizing locality-level dengue incidence data across the state of Sonora, 2) to determine the correlation between the spatial pattern of dengue cases during an outbreak in Hermosillo, a large urban area, and neighborhood-level socio-economic and water supply factors using a novel case-control study design, and 3) to determine how dengue cases disseminated across two arid cities, Hermosillo and Navojoa, and to determine if changing socio-demographic patterns were similar between cities. Results from the first ecological study indicated that the distribution of dengue across the state was associated most strongly with the climatic gradient and, secondarily, by population size and lack of education. Underreporting in rural areas with lower access to transportation infrastructure was also detected. We demonstrated that a spatially-based case-control study design was useful in identifying associations between dengue transmission and neighborhood-level characteristics related to population density, lack of access to healthcare and water supply restrictions. Finally, the spatio-temporal study identified common patterns between the two cities/outbreaks. Dengue transmission arose and was maintained for 2-3 months in specific foci areas characterized by low access to healthcare and then the disease moved to contiguous areas. Recommendations for surveillance and control programs based on these results include: 1) in small localities at risk of transmission a combination of active and passive surveillance should be carried out for a period of time to determine if transmission is occurring, 2) monitoring water storage practices during water restrictions and ensuring appropriate messaging about covering storage containers should be made, and 3) spatial monitoring of dengue cases and agency reaction to initial disease occurrence could reduce spread to adjacent areas.

Landscape connectivity models aim to map the links or corridors that wildlife would or do use between patches of habitat. Migratory species such as elk traverse between such patches which serve as seasonal ranges. The goal of this study was to compare and contrast the suitability of several landscape connectivity models for describing and predicting migration in a long-distance migrant. We measured the suitability of connectivity models for covering and predicting the migratory movements of elk in the Greater Yellowstone Ecosystem. GPS point data was converted to sequential networks for multiple populations of elk. GPS data was also used to delineate the summer and winter ranges of each population. The kernel density of routes in the networks was measured for comparison to connectivity models. The ranges served as the patches to be connected by such models. A resistance surface was produced using reclassified landcover data for mapping habitat suitability and linear road data for human presence or obstruction to movement. Landscape connectivity was measured for eleven migratory elk populations using three distinct models. The first measured connectivity using circuit theory; the second, agent based modeling; the third, least cost corridors. The model results were compared to the migratory network density by measuring correlation. This was followed by a new method of measuring the influence of autocorrelation between the models and networks. Some of the models were then altered to test for suspected influences. This study shows that least cost corridors and circuit theory can are limited in their ability to predict the migratory movements between summer and winter ranges but only so much. They lack the ability to predict exploratory movements that do not link conspicuous ranges to each other. They also lack the ability to account for all avoidance behaviors in the landscape. Our results suggest that connectivity models need improvement by accounting for exploration outside of prime habitat. It also suggests connectivity models are not adequate predictors of migratory movements and not suited to conservation planning of migratory networks. This supports Sawyer's (et al. 2009) ungulate conservation planning of considering connectivity but basing priority on migratory landscape usage. It is assumed that fragmentation or loss in connectivity impedes seasonal migration, cutting off wildlife from resources (Rudnick et al. 2012). This study shows that migratory elk are actually using less than prime and supposedly fragmented habitat in migration and that there is more than connectivity at play.

The American West, once characterized by open spaces, low population densities, and the dominance of primary sector activities, is experiencing high rates of population growth related to amenity migration. Those same natural amenities that attract migration are often degraded by housing growth and associated development; however the extent of impacts and the specific features of the environment that attract amenity migration are poorly understood. This change in land use was investigated by first examining the impacts of exurbanization on three ecosystem indicators (fire hazard, water availability, and distance effects of houses and roads) and secondly by considering the socio-cultural and aesthetic drivers of amenity migration in the Sonoita Plain, Arizona, USA. When the impacts of houses and roads on ecosystem function were considered, 98% of exurban areas were "highly" or "very highly" impacted, compared to 100% for suburban areas and 35% for rural areas. These results were striking because exurban areas have impacts on ecosystem function comparable to those of suburban areas, despite the fact that they support significantly lower population densities. The importance of privacy in the spatial distribution of exurban development was examined through GIS viewshed analysis. Desire for privacy was manifested in the home locations selected by exurbanites, with the large majority of homes located where the inhabitants see few, if any, neighbors. Scenic beauty is a common pull factor for amenity and this study examined three visual quality metrics (naturalness, visual scale and complexity) in relation to the location of exurban houses. Exurban households see significantly more vegetation, more rugged terrain, and a larger viewshed than would be expected if they were randomly distributed. There is evidence that visual complexity throughout the viewshed may be more important than seeing the very highest peaks. These results call into question the use of county-level scales of analysis for the study of landscape preferences, which may miss key landscape aesthetic drivers of preference. Amenity drivers have important implications for the distribution of development and can inform growth strategies designed to minimize negative ecological impacts and protect visual quality of the environment.

Droughts are a recurrent part of our climate, and are still considered to be one of the most complex and least understood of all natural hazards in terms of their impact on the environment. In recent years drought has become more common and more severe across the world. For more than a decade, the US southwest has faced extensive and persistent drought conditions that have impacted vegetation communities and local water resources. The focus of this work is achieving a better understanding of the impact of drought on the lands of the Hopi Tribe and Navajo Nation, situated in the Northeastern corner of Arizona. This research explores the application of remote sensing data and geospatial tools in two studies to monitor drought impacts on vegetation productivity. In both studies we used land surface phenometrics as the data tool. In a third related study, I have compared satellite-derived land surface phenology (LSP) to field observations of crop stages at the Maricopa Agricultural Center to achieve a better understanding of the temporal sensitivity of satellite derived phenology of vegetation and understand their accuracy as a tool for monitoring change. The first study explores long-term vegetation productivity responses to drought. The paper develops a framework for drought monitoring and assessment by integrating land cover, climate, and topographical data with LSP. The objective of the framework is to detect long-term vegetation changes and trends in the Normalized Difference Vegetation Index (NDVI) related productivity. The second study examines the major driving forces of vegetation dynamics in order to provide valuable spatial information related to inter-annual variability in vegetation productivity for mitigating drought impacts. The third study tests the accuracy of remote sensing-derived LSP by comparing them to the actual seasonal phases of crop growth. This provides a way to compare and validate the various LSP algorithms, and more crucially, helps to characterize the remote sensing-based metrics that contrast with the actual biological phenophases of the crops. These studies demonstrate how remote sensing data and simple statistical tools can be used to assess drought effects on vegetation productivity and to inform about land conditions, as well as to better understand the accuracy of satellite derived LSP.

Adequate water for ecosystems and humans is at a premium as the global population increases and the climate changes. Coping with these impacts requires tools to improve water governance and water management through legal or policy mechanisms. Water governance generates laws, policies, and rulings and water management implements those laws, policies, and rulings and rulings through management decisions. A key concern of water governance is balancing human and ecosystem water needs. Effective governance that promotes sustainable use of water resources to maintain ecosystem integrity is challenging. Many regions do not have sufficient resources for water management or water for ecosystems is not protected under traditional legal mechanisms. The challenge of improving water governance for ecosystems is, therefore, twofold. First, there is a need to provide resources that build the capacity of water managers to allocate water to ecosystems. Second, mechanisms to promote effective transformation of environmental flow needs into policy or practice are required. This research provides methods to advance water management by: 1) assessing environmental flow needs through creation of a geospatial database and 2) improving stakeholder engagement through lessons learned from three multi-year stakeholder engagement processes. Appendix A describes the current understanding of the link between hydrology and riparian and aquatic ecosystems in Arizona through synthesis of environmental flow needs. The synthesized information, stored in a geospatial database, can be used by water managers to determine the water needs to maintain riparian and aquatic habitats. Review of 121 studies reveals that there are very few analyses of surface water and groundwater requirements for intermittent or ephemeral river systems, and there are only limited generalizable data for aquatic species. This database can be used to identify critical geographic and topical knowledge gaps, as well as serve as a single place for water and land managers to assess and use the most current research to inform management decisions. Appendix B provides an empirical example of engagement to promote social learning as a way to preserve water for the environment when law does not protect environmental flows. Through 43 focus groups with 226 individuals representing a diversity of interests, we determined that there was common ground on concerns about water conservation, cooperation, financial incentives, and multiple benefits for water use. Through this engagement process, we found that identifying and then building common ground requires attention to details. These details include the process of analyzing qualitative data and methods for displaying complex information, which are not frequently discussed in the social learning or stakeholder engagement literature. Appendix C presents a framework for designing effective stakeholder engagement based on the experiences of the University of Arizona Water Resources Research Center in three separate processes that engaged water experts. The proposed framework provides an iterative and flexible approach centered on a bridging organization that can bring people together and keep the engagement process moving forward. As illustrated through an evaluation of the three projects, the proposed framework provides for inclusivity, interactiveness, and flexibility in engagement through guidance by a steering committee and iteratively examining the water resource management problem. While further assessment is necessary, it appears that this framework is general enough to be applicable across projects at three different scales and with three separate sets of goals, yet detailed enough to provide a tangible approach that could aid other processes where the goal is implementing and evaluating expert engagement to solve complex problems and promote social learning. Previous studies on water governance have focused predominantly on the identification of the current problems with governance. However, because humans have an important role in shaping the global water cycle, the time has come to focus on solutions. In order to further water management solutions, a better understanding of the tools needed to manage water for ecosystems and effective methods for co-producing knowledge or encouraging social learning are needed. This research provides a regional example of approaches to advance water management using a tool to assess environmental flows needs and frameworks for promoting common ground and social learning in stakeholder engagement.