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.

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No description available.

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.

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About the Book: This selected series of international studies is aimed at achieving a balance between the house and the desert, assuming an energy-conscious future. In the book experimental houses and examples from the world's deserts are discussed, documented and illustrated. The studies were sponsored by the Arid Lands Natural Resources Committee of the University of Arizona.