Matching Items (13)

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Effects of urbanization on bat habitat use in the Phoenix Metropolitan Region, Arizona, USA: a multi-scale landscape analysis

Description

Context – Urbanization can have negative effects on bat habitat use through the loss and isolation of habitat even for volant bats. Yet, how bats respond to the changing

Context – Urbanization can have negative effects on bat habitat use through the loss and isolation of habitat even for volant bats. Yet, how bats respond to the changing landscape composition and configuration of urban environments remains poorly understood.

Objective – This study examines the relationship between bat habitat use and landscape pattern across multiple scales in the Phoenix metropolitan region. My research explores how landscape composition and configuration affects bat activity, foraging activity, and species richness (response variables), and the distinct habitats that they use.

Methods – I used a multi-scale landscape approach and acoustic monitoring data to create predictive models that identified the key predictor variables across multiple scales within the study area. I selected three scales with the intent of capturing the landscape, home range, and site scales, which may all be relevant for understanding bat habitat use.

Results – Overall, class-level metrics and configuration metrics best explained bat habitat use for bat species associated with this urban setting. The extent and extensiveness of water (corresponding to small water bodies and watercourses) were the most important predictor variables across all response variables. Bat activity was predicted to be high in native vegetation remnants, and low in native vegetation at the city periphery. Foraging activity was predicted to be high in fine-scale land cover heterogeneity. Species richness was predicted to be high in golf courses, and low in commercial areas. Bat habitat use was affected by urban landscape pattern mainly at the landscape and site scale.

Conclusions – My results suggested in hot arid urban landscapes water is a limiting factor for bats, even in urban landscapes where the availability of water may be greater than in outlying native desert habitat. Golf courses had the highest species richness, and included the detection of the uncommon pocketed free-tailed bat (Nyctinomops femorosaccus). Water cover types had the second highest species richness. Golf courses may serve as important stop-overs or refuges for rare or elusive bats. Urban waterways and golf courses are novel urban cover types that can serve as compliments to urban preserves, and other green spaces for bat conservation.

Contributors

Agent

Created

Date Created
  • 2016

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Land use and land cover classification using deep learning techniques

Description

Large datasets of sub-meter aerial imagery represented as orthophoto mosaics are widely available today, and these data sets may hold a great deal of untapped information. This imagery has a

Large datasets of sub-meter aerial imagery represented as orthophoto mosaics are widely available today, and these data sets may hold a great deal of untapped information. This imagery has a potential to locate several types of features; for example, forests, parking lots, airports, residential areas, or freeways in the imagery. However, the appearances of these things vary based on many things including the time that the image is captured, the sensor settings, processing done to rectify the image, and the geographical and cultural context of the region captured by the image. This thesis explores the use of deep convolutional neural networks to classify land use from very high spatial resolution (VHR), orthorectified, visible band multispectral imagery. Recent technological and commercial applications have driven the collection a massive amount of VHR images in the visible red, green, blue (RGB) spectral bands, this work explores the potential for deep learning algorithms to exploit this imagery for automatic land use/ land cover (LULC) classification. The benefits of automatic visible band VHR LULC classifications may include applications such as automatic change detection or mapping. Recent work has shown the potential of Deep Learning approaches for land use classification; however, this thesis improves on the state-of-the-art by applying additional dataset augmenting approaches that are well suited for geospatial data. Furthermore, the generalizability of the classifiers is tested by extensively evaluating the classifiers on unseen datasets and we present the accuracy levels of the classifier in order to show that the results actually generalize beyond the small benchmarks used in training. Deep networks have many parameters, and therefore they are often built with very large sets of labeled data. Suitably large datasets for LULC are not easy to come by, but techniques such as refinement learning allow networks trained for one task to be retrained to perform another recognition task. Contributions of this thesis include demonstrating that deep networks trained for image recognition in one task (ImageNet) can be efficiently transferred to remote sensing applications and perform as well or better than manually crafted classifiers without requiring massive training data sets. This is demonstrated on the UC Merced dataset, where 96% mean accuracy is achieved using a CNN (Convolutional Neural Network) and 5-fold cross validation. These results are further tested on unrelated VHR images at the same resolution as the training set.

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Agent

Created

Date Created
  • 2016

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Scientific Foundations and Problem-Driven Case Studies of Landscape Sustainability: Sustainability of Human-Environment Systems Through the Lens of the Landscape

Description

The science community has made efforts for over a half century to address sustainable development, which gave birth to sustainability science at the turn of the twenty-first century. Along

The science community has made efforts for over a half century to address sustainable development, which gave birth to sustainability science at the turn of the twenty-first century. Along with the development of sustainability science during the past two decades, a landscape sustainability science (LSS) perspective has been emerging. As interests in LSS continue to grow rapidly, scholars are wondering what LSS is about and how LSS fits into sustainability science, while practitioners are asking how LSS actually contributes to sustainability in the real world. To help address these questions, this dissertation research aims to explore the currently underused problem-driven, diagnostic approach to enhancing landscape sustainability through an empirical example of urbanization-associated farmland loss (UAFL). Based mainly on multimethod analysis of bibliographic information, the dissertation explores conceptual issues such as how sustainability science differs from conventional sustainable development research, and how the past, present, and future research needs of LSS evolve. It also includes two empirical studies diagnosing the issue of urban expansion and the related food security concern in the context of China, and proposes a different problem framing for farmland preservation such that stakeholders can be more effectively mobilized. The most important findings are: (1) Sustainability science is not “old wine in a new bottle,” and in particular, is featured by its complex human-environment systems perspective and value-laden transdisciplinary perspective. (2) LSS has become a vibrant emerging field since 2004-2006 with over three-decade’s intellectual accumulation deeply rooted in landscape ecology, yet LSS has to further embrace the two featured perspectives of sustainability science and to conduct more problem-driven, diagnostic studies of concrete landscape-relevant sustainability concerns. (3) Farmland preservationists’ existing problem framing of UAFL is inappropriate for its invalid causal attribution (i.e., urban expansion is responsible for farmland loss; farmland loss is responsible for decreasing grain production; and decreasing grain production instead of increasing grain demand is responsible for grain self-insufficiency); the real problem with UAFL is social injustice due to collective action dilemma in preserving farmland for regional and global food sufficiency. The present research provides broad implications for landscape scientists, the sustainability research community, and UAFL stakeholders.

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Agent

Created

Date Created
  • 2020

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Evaluating the impact of land cover composition on water, energy, and carbon fluxes in urban and rangeland ecosystems of the southwestern United States

Description

Urbanization and woody plant encroachment, with subsequent brush management, are two significant land cover changes that are represented in the southwestern United States. Urban areas continue to grow, and rangelands

Urbanization and woody plant encroachment, with subsequent brush management, are two significant land cover changes that are represented in the southwestern United States. Urban areas continue to grow, and rangelands are undergoing vegetation conversions, either purposely through various rangeland management techniques, or by accident, through inadvertent effects of climate and management. This thesis investigates how areas undergoing land cover conversions in a semiarid region, through urbanization or rangeland management, influences energy, water and carbon fluxes. Specifically, the following scientific questions are addressed: (1) what is the impact of different urban land cover types in Phoenix, AZ on energy and water fluxes?, (2) how does the land cover heterogeneity influence energy, water, and carbon fluxes in a semiarid rangeland undergoing woody plant encroachment?, and (3) what is the impact of brush management on energy, water, and carbon fluxes?

The eddy covariance technique is well established to measure energy, water, and carbon fluxes and is used to quantify and compare flux measurements over different land surfaces. Results reveal that in an urban setting, paved surfaces exhibit the largest sensible and lowest latent heat fluxes in an urban environment, while a mesic landscape exhibits the largest latent heat fluxes, due to heavy irrigation. Irrigation impacts flux sensitivity to precipitation input, where latent heat fluxes increase with precipitation in xeric and parking lot landscapes, but do not impact the mesic system. In a semiarid managed rangeland, past management strategies and disturbance histories impact vegetation distribution, particularly the distribution of mesquite trees. At the site with less mesquite coverage, evapotranspiration (ET) is greater, due to greater grass cover. Both sites are generally net sinks of CO2, which is largely dependent on moisture availability, while the site with greater mesquite coverage has more respiration and generally greater gross ecosystem production (GEP). Initial impacts of brush management reveal ET and GEP decrease, due to the absence of mesquite trees. However the impact appears to be minimal by the end of the productive season. Overall, this dissertation advances the understanding of land cover change impacts on surface energy, water, and carbon fluxes in semiarid ecosystems.

Contributors

Agent

Created

Date Created
  • 2017

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Shifting the sustainability paradigm: co-creating thriving living systems through regenerative development

Description

Sustainability research and action in communities should be holistic, integrating sociocultural, biogeophysical, and spiritual components and their temporal and spatial dynamics toward the aim of co-creating thriving living systems. Yet

Sustainability research and action in communities should be holistic, integrating sociocultural, biogeophysical, and spiritual components and their temporal and spatial dynamics toward the aim of co-creating thriving living systems. Yet scientists and practitioners still struggle with such integration. Regenerative development (RD) offers a way forward. RD focuses on shifting the consciousness and thinking underlying (un)sustainability as well as their manifestation in the physical world, creating increasingly higher levels of health and vitality for all life across scales. However, tools are nascent and relatively insular. Until recently, no empirical scientific research studies had been published on RD processes and outcomes.

My dissertation fills this gap in three complementary studies. The first is an integrative review that contextualizes regenerative development within the fields of sustainability, sustainable design and development, and ecology by identifying its conceptual elements and introducing a regenerative landscape development paradigm. The second study integrates complex adaptive systems science, ecology, sustainability, and regenerative development to construct and pilot the first iteration of a holistic sustainable development evaluation tool—the Regenerative Development Evaluation Tool—in two river restoration projects. The third study builds upon the first two, integrating scientific knowledge with existing RD and sustainable community design and development practices and theory to construct and pilot a Regenerative Community Development (RCD) Framework. Results indicate that the RCD Framework and Tools, when used within a regenerative landscape development paradigm, can facilitate: (1) shifts in thinking and development and design outcomes to holistic and regenerative ones; (2) identification of areas where development and design projects can become more regenerative and ways to do so; and (3) identification of factors that potentially facilitate and impede RCD processes. Overall, this research provides a direction and tools for holistic sustainable development as well as foundational studies for further research.

Contributors

Agent

Created

Date Created
  • 2019

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Mapping and modeling illicit and clandestine drivers of land use change: urban expansion in Mexico City and deforestation in Central America

Description

Anthropogenic land use has irrevocably transformed the natural systems on which humankind relies. Understanding where, why, and how social and economic processes drive globally-important land-use changes, from deforestation to urbanization,

Anthropogenic land use has irrevocably transformed the natural systems on which humankind relies. Understanding where, why, and how social and economic processes drive globally-important land-use changes, from deforestation to urbanization, has advanced substantially. Illicit and clandestine activities--behavior that is intentionally secret because it breaks formal laws or violates informal norms--are poorly understood, however, despite the recognition of their significant role in land change. This dissertation fills this lacuna by studying illicit and clandestine activity and quantifying its influence on land-use patterns through examining informal urbanization in Mexico City and deforestation Central America. The first chapter introduces the topic, presenting a framework to examine illicit transactions in land systems. The second chapter uses data from interviews with actors involved with land development in Mexico City, demonstrating how economic and political payoffs explain the persistence of four types of informal urban expansion. The third chapter examines how electoral politics influence informal urban expansion and land titling in Mexico City using panel regression. Results show land title distribution increases just before elections, and more titles are extended to loyal voters of the dominant party in power. Urban expansion increases with electoral competition in local elections for borough chiefs and legislators. The fourth chapter tests and confirms the hypothesis that narcotrafficking has a causal effect on forest loss in Central America from 2001-2016 using two proxies of narcoactivity: drug seizures and events from media reports. The fifth chapter explores the spatial signature and pattern of informal urban development. It uses a typology of urban informality identified in chapter two to hypothesize and demonstrate distinct urban expansion patterns from satellite imagery. The sixth and final chapter summarizes the role of illicit and clandestine activity in shaping deforestation and urban expansion through illegal economies, electoral politics, and other informal transactions. Measures of illicit and clandestine activity should--and could--be incorporated into land change models to account for a wider range of relevant causes. This dissertation shines a new light on the previously hidden processes behind ever-easier to detect land-use patterns as earth observing satellites increase spatial and temporal resolution.

Contributors

Agent

Created

Date Created
  • 2019

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Phoenix's place for the homeless: stories from the Maricopa County Human Services Campus

Description

This thesis investigates how homeless men and women who use one of only six human services campuses (hscs) in the nation negotiate the stigmatization they may feel as homeless people

This thesis investigates how homeless men and women who use one of only six human services campuses (hscs) in the nation negotiate the stigmatization they may feel as homeless people living in Phoenix, Arizona. An hsc centralizes services to one area of the city to decrease the run around of scattered-site service delivery. It also creates a legitimized space for the homeless in the city. A place for the homeless can be a rarity in cities like Phoenix that have a history of implementing revanchist policies and neo-liberal land use planning, most notably found in its downtown revitalization efforts. During Phoenix's development as a major metropolitan area, the homeless population emerged and lived a life on the margins until the 2005 creation of the Human Services Campus. This research unearths the experiences of homeless men and women who use the HSC today. I used qualitative methods, including document review, 14 in-depth interviews with homeless men and women, 7 interviews with service providers, informal conversations with additional homeless clients, and 14 months of field observations at the HSC to collect the data presented in this thesis. The results of this research illustrate reasons why the homeless clients interviewed were sensitive to the stigmatization of their social status, and how they managed their stigmatization through relationships with homeless peers and staff on the HSC. The presence of an action plan to exit homelessness was critical to the nature of these relationships for clients, because it influenced how clients perceived their own stigmatization as a homeless person.

Contributors

Agent

Created

Date Created
  • 2011

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Practicing community-based Truku (indigenous) language policy: dialogues of hope at the intersection of language revitalization, identity development, and community rebuilding

Description

The dissertation focuses on one Truku (Indigenous) village in eastern Taiwan and aims to understand the processes and possibilities of bottom-up language revitalization. In 2012, the National Geographic Genographic Legacy

The dissertation focuses on one Truku (Indigenous) village in eastern Taiwan and aims to understand the processes and possibilities of bottom-up language revitalization. In 2012, the National Geographic Genographic Legacy Fund supported the village to start a community-driven language revitalization initiative. Drawing on scholarship guided by critical Indigenous research methodologies, critical sociocultural approaches to language policy and planning, and sociocultural approaches to learning, this study is an attempt to generate qualitative ethnographic research to facilitate local praxis. The major findings are four: Firstly, after decades of colonialism, villagers' lived experiences and language ideological standpoints vary significantly across generations and households, which constraints the possibility of collective endeavors. Secondly, building on previous scholars' emphasis on "ideological clarification" prior to language revitalization, I identify the dimension of embodied ideological differences, using cultural historical activity theory to illustrate how certain "mainstream" artifacts (e.g. orthography) can confine orally dominant elders' capacity to contribute. In a similar vein, by closely examining children's voices and language performances, I highlight children's theory of language as relationship-building and a theory of learning as participation in communities of participation, which stand in stark contrast to adult educators' constructs of acquisition and proficiency in traditional SLA. Finally, inspired by children and elders' voices, methodologically I argue for a relational conceptualization of agency and propose a relationship-oriented language revitalization framework. Such framework values and incorporates existing social relationships in praxis, and requires researchers and practitioners to humbly recognize the work of power in social relations and develop a trusting, reflective bond with the villagers before rushing to impose agendas. This dissertation contributes to the scholarship of language policy and planning by incorporating sociocultural learning theories designed to generate praxis-oriented analysis. By contextualizing identity and SLA processes in an Indigenous context, the study also illuminates the affective dimension of language learning and education. Overall this study offers valuable insights for scholars, educators, and practitioners interested in community-based language education. Equally important, this research represents the voices of multiple generations of Truku people, deeply committed to ensuring that future generations remain connected to their heritage language, knowledge system, and ways of being.

Contributors

Agent

Created

Date Created
  • 2014

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How cities think: knowledge-action systems analysis for urban sustainability in San Juan, Puerto Rico

Description

With more than 70 percent of the world's population expected to live in cities by 2050, it behooves us to understand urban sustainability and improve the capacity of city planners

With more than 70 percent of the world's population expected to live in cities by 2050, it behooves us to understand urban sustainability and improve the capacity of city planners and policymakers to achieve sustainable goals. Producing and linking knowledge to action is a key tenet of sustainability science. This dissertation examines how knowledge-action systems -- the networks of actors involved in the production, sharing and use of policy-relevant knowledge -- work in order to inform what capacities are necessary to effectively attain sustainable outcomes. Little is known about how knowledge-action systems work in cities and how they should be designed to address their complexity. I examined this question in the context of land use and green area governance in San Juan, Puerto Rico, where political conflict exists over extensive development, particularly over the city's remaining green areas. I developed and applied an interdisciplinary framework -- the Knowledge-Action System Analysis (KASA) Framework --that integrates concepts of social network analysis and knowledge co-production (i.e., epistemic cultures and boundary work). Implementation of the framework involved multiple methods --surveys, interviews, participant observations, and document--to gather and analyze quantitative and qualitative data. Results from the analysis revealed a diverse network of actors contributing different types of knowledge, thus showing a potential in governance for creativity and innovation. These capacities, however, are hindered by various political and cultural factors, such as: 1) breakdown in vertical knowledge flow between state, city, and local actors; 2) four divergent visions of San Juan's future emerging from distinct epistemic cultures; 3) extensive boundary work by multiple actors to separate knowledge and planning activities, and attain legitimacy and credibility in the process; 4) and hierarchies of knowledge where outside expertise (e.g., private planning and architectural firms) is privileged over others, thus reflecting competing knowledge systems in land use and green area planning in San Juan. I propose a set of criteria for building just and effective knowledge-action systems for cities, including: context and inclusiveness, adaptability and reflexivity, and polycentricity. In this way, this study also makes theoretical contributions to the knowledge systems literature specifically, and urban sustainability in general.

Contributors

Agent

Created

Date Created
  • 2012

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Landscape planning and biogeochemistry: estimating and analyzing carbon sequestration efficacy in dryland open space

Description

Despite public demand for climate change mitigation and natural open space conservancy, existing political and design efforts are only beginning to address the declining efficacy of the biotic carbon pool

Despite public demand for climate change mitigation and natural open space conservancy, existing political and design efforts are only beginning to address the declining efficacy of the biotic carbon pool (C-pool) to sequester carbon. Advances in understanding of biogeochemical processes have provided methods for estimating carbon embodied in natural open spaces and enhancing carbon sequestration efficacy. In this study, the benefits of carbon embodied in dryland open spaces are determined by estimating carbon flux and analyzing ecological, social, and economic benefits provided by sequestered carbon. Understanding the ecological processes and derived benefits of carbon exchange in dryland open spaces will provide insight into enhancing carbon sequestration efficacy. Open space carbon is estimated by calculating the amount of carbon sequestration (estimated in Mg C / ha / y) in dryland open space C-pools. Carbon sequestration in dryland open spaces can be summarized in five open space typologies: hydric, mesic, aridic, biomass for energy agriculture, and traditional agriculture. Hydric (wetland) systems receive a significant amount of moisture; mesic (riparian) systems receive a moderate amount of moisture; and aridic (dry) systems receive low amounts of moisture. Biomass for energy production (perennial biomass) and traditional agriculture (annual / traditional biomass) can be more effective carbon sinks if managed appropriately. Impacts of design interventions to the carbon capacity of dryland open space systems are calculated by estimating carbon exchange in existing open space (base case) compared to projections of carbon sequestered in a modified system (prototype design). A demonstration project at the Lower San Pedro River Watershed highlights the potential for enhancing carbon sequestration. The site-scale demonstration project takes into account a number of limiting factors and opportunities including: availability of water and ability to manipulate its course, existing and potential vegetation, soil types and use of carbon additives, and land-use (particularly agriculture). Specific design challenges to overcome included: restoring perennial water to the Lower San Pedro River, reestablishing hydric and mesic systems, linking fragmented vegetation, and establishing agricultural systems that provide economic opportunities and act as carbon sinks. The prototype design showed enhancing carbon sequestration efficacy by 128-133% is possible with conservative design interventions.

Contributors

Agent

Created

Date Created
  • 2012