28 research outputs found

    African New Towns:

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    Since the economic shifts of the 1990s, New Towns have become an increasingly popular approach to urban development across the African continent. While New Towns are not a new development model, their contemporary materialisation often targets middle- and highincome buyers, leaving no space for low-income residents. Strict regulations in these exclusive developments often impede spatial appropriations by the informal sector such as fresh markets, unregulated housing, street kiosks and ‘public’ transit options. As a result, this approach may exacerbate spatial segregation and increase the visibility of economic inequality. This research addresses contemporary African New Towns as a group through the lens of urban design, identifying shared spatial challenges across a dataset of 146 New Towns. Through three case studies (Sheikh Zayed City, Egypt; BuraNEST, Ethiopia, and Kilamba, Angola) it takes a deeper look at the idiosyncrasies of individual New Towns, and the diversity of examples within this group. By bringing together wider trends with the case studies, this study translates challenges into potentials for future New Towns in the form of adaptive planning and design principles. Through a series of semi-structured interviews, transdisciplinary workshops and Research Through Design exercises, the principles are tested, refined, and validated by peer review. The study concludes that these principles can be an effective starting tool for developers, planners, and decision-makers initiating New Towns in Africa. It also concludes that the principles must be adapted locally according to geographic, political, and social contexts and urgencies

    African New Towns

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    The New Towns (mixed use urban developments planned and built from scratch) initiated across the African continent since 1990 are overwhelmingly designed and built according to urban planning models from the previous century (Watson 2013; Marcinkowski 2018; Keeton and Provoost 2019). This has produced a generation of New Towns with rigid physical infrastructure and strict building regulations, that do not support the spatial manifestations of the ‘informal’ sector. As a result, these New Towns may become insular enclaves and informal settlements may develop adjacently to them. Residents of these adjacent areas may not have access to the services and amenities offered within the New Towns (Keeton and Provoost 2019). Coupled with the implicit vulnerabilities of emerging and threshold economies, the contextual mismatch of the imported urban models exacerbates spatial segregation at an urban scale. Additionally, contemporary New Town models often do not take current climate variability or future climate change threats into account. As implemented in the African context, they rarely respond effectively to surrounding natural landscapes or environmental sensitivities (Keeton and Nijhuis 2019). Building on the arguments that (1) equal access to resources is a key component of sustainable development and that (2) urban planning benefits from new linkages between critical social theory and environmental science, this research proposes that applying adaptive urban planning principles to New Towns in the African context can increase ecological sustainability and social inclusivity (WCED 1987; Fainstein and Campbell 2012). The objective of this research is therefore to address the spatial challenges of African New Towns by developing an alternative planning and design approach that acknowledges both social and environmental dimensions, as well as the constant state of change that all cities exhibit. This is done by addressing four main research questions: (1) What are the spatial problems of African New Towns caused by the application of common planning approaches? (2) What are the principles of a more adaptive and sustainable planning and design approach and how can they address these problems? (3) How and to what extent can the adaptive planning and design principles be improved and applied? And finally, (4) As a result of the findings, how can adaptive planning approaches and the related principles be implemented? The research first identifies the spatial challenges specific to contemporary African New Towns through a combination of empirical data collection and literature review. The research moves forward to bring these shared spatial challenges together with a set of guidelines for New Towns originally written by Michelle Provoost as an addition to UN-Habitat’s New Urban Agenda (Provoost 2016). The analysis of shared spatial challenges is used to revise, expand and refine these guidelines into a set of adaptive planning and design principles specific to African New Towns. The resulting principles are then tested by applying them through case study analysis of three existing New Towns to establish their universality as well as their ability to acknowledge local specificities. In the final phase of the research, two short-term workshops validate the results by testing implementation of the principles in two African New Towns (Tatu City, Kenya and Mahonda, Zanzibar). The research concludes that the adaptive planning and design principles can be an effective starting point for stakeholders involved in the development of New Towns across Africa. It furthermore concludes that these principles must be adapted locally to meet the individual urgencies of different sites. This research contributes to the existing body of literature on contemporary African New Towns (Watson 2014; Murray 2017; Van Noorloos and Kloosterboer 2018; Keeton and Provoost 2019). Notably, most authors working on this topic primarily employ internet sources or a single case study to build their arguments, which can be problematic in the African context where remotely-sourced data is often unreliable and New Towns as a group exhibit vast divergences that may limit the transferability of results from individual case studies. This research therefore fills a knowledge gap by bringing together empirical evidence acquired during fieldwork in Angola, Egypt, Ethiopia, Ghana, Kenya, Morocco, and Tanzania, combined with literature review and the results of interdisciplinary workshops to support its claims. It also contributes to the current debate on normative assumptions regarding planning in the Global South (Watson 2002; Watson 2016; Cirolia and Berrisford 2017), and directly addresses the disconnect between academia and practice regarding contemporary African New Towns (Grubbaur 2019; Keeton and Provoost 2019). Finally, this study aims to provide an alternative approach for planners, developers and decision-makers initiating tomorrow’s New Towns in Africa

    Participatory Workshops as a Tool for Building Inclusivity in New Towns in Africa

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    Africa is currently the fastest-urbanizing continent in the world. As part of this rapid growth, New Towns are increasingly employed by private developers as a means of providing well-serviced urban environments to middle- and upper-income groups. These comprehensively-planned New Towns are often seen in contrast to the perceived ‘chaos’ and ‘congestion’ of large African cities. As a result, two urban forms, the highly controlled New Towns and the unregulated settlements at their edges, engage in complex social and economic exchanges, but remain spatially segregated and socially exclusive. Current research points to the need for an alternative approach to top-down New Town planning in Africa. Participatory workshops are one alternative that can offer planners access to local knowledge that is otherwise difficult to access. This paper explores the potential of short-term reflective, design, and serious gaming workshops by reflecting on the experiences of the authors in four recent workshops. The paper evaluates the effectiveness of these workshops as useful tools to increase inclusivity in African New Towns by bringing together stakeholders with competing agendas and supporting open discussion, negotiation, and informed decision-making. The paper concludes that participation from stakeholder groups that would normally be marginalized from the planning process (such as current residents, temporary users, and residents of adjacent unregulated communities), can offer new insights to planning bodies and inform more inclusive New Towns across the continent

    Galaxy density profiles and shapes -- II. selection biases in strong lensing surveys

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    [Abridged] Many current and future astronomical surveys will rely on samples of strong gravitational lens systems to draw conclusions about galaxy mass distributions. We use a new strong lensing pipeline (presented in Paper I of this series) to explore selection biases that may cause the population of strong lensing systems to differ from the general galaxy population. Our focus is on point-source lensing by early-type galaxies with two mass components (stellar and dark matter) that have a variety of density profiles and shapes motivated by observational and theoretical studies of galaxy properties. We seek not only to quantify but also to understand the physics behind selection biases related to: galaxy mass, orientation and shape; dark matter profile parameters such as inner slope and concentration; and adiabatic contraction. We study how all of these properties affect the lensing Einstein radius, total cross-section, quad/double ratio, and image separation distribution. We find significant (factors of several) selection biases with mass; orientation, for a given galaxy shape at fixed mass; cusped dark matter profile inner slope and concentration; concentration of the stellar and dark matter deprojected Sersic models. Interestingly, the intrinsic shape of a galaxy does not strongly influence its lensing cross-section when we average over viewing angles. Our results are an important first step towards understanding how strong lens systems relate to the general galaxy population.Comment: 26 pages, 15 figures; paper I at arXiv:0808.2493; accepted for publication in MNRAS (minor revisions); PDF file with full resolution figures at http://www.sns.ias.edu/~rmandelb/paper2.pd

    Climate migration and well-being: a study on ex-pastoralists in northern Kenya

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    As the impacts of climate change intensify globally, scholars and policymakers are increasingly interested in determining the factors that lead to the success or failure of climate adaptation strategies. This paper investigates the well-being outcomes of ex-pastoralists in northern Kenya who have migrated to towns in response to severe droughts. Focusing on Marsabit Town, the study employs a comparative design with primary survey data to analyze the well-being outcomes resulting from migration as an adaptation strategy. We contrast two heterogeneous groups of former pastoralists: a “settled group” that was already residing in Marsabit Town before ending their pastoral activities and a “migrant group” that relocated to Marsabit Town at the time of abandoning pastoralism. Our analysis reveals significant differences in well-being outcomes between these groups, with the migrant group often experiencing deterioration in their well-being levels. Key predictors of poorer well-being outcomes include the loss of all livestock, informal housing, and failure to transition into agricultural work, which often results in dependence on casual labor. Additionally, many migrants continue to experience poor subjective well-being—referring to their personal satisfaction with the quality of life—years after their livelihood transition. These insights offer a nuanced understanding of the well-being outcomes of migration-as-adaptation among heterogeneous groups of ex-pastoralists and underscore the need for customized livelihood support strategies for the most at-risk populations

    Creating A Research Writing Environment With Personalized Library Instruction

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    Inman E. Page Library participated in the ARCL\u27s Assessment in Action project led by Academic Librarian kYmberly Keeton. This is the final project poster presented by Ms. Keeton at ALA\u27s 2016 Annual at Orlando, Florida. The poster shows how one faculty library group comes together to explore assessing students’ writing intensive projects in three academic semesters within a scholarly learning space at a Historically Black College University

    Galaxy density profiles and shapes -- I. simulation pipeline for lensing by realistic galaxy models

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    Studies of strong gravitational lensing in current and upcoming wide and deep photometric surveys, and of stellar kinematics from (integral-field) spectroscopy at increasing redshifts, promise to provide valuable constraints on galaxy density profiles and shapes. However, both methods are affected by various selection and modelling biases, whch we aim to investigate in a consistent way. In this first paper in a series we develop a flexible but efficient pipeline to simulate lensing by realistic galaxy models. These galaxy models have separate stellar and dark matter components, each with a range of density profiles and shapes representative of early-type, central galaxies without significant contributions from other nearby galaxies. We use Fourier methods to calculate the lensing properties of galaxies with arbitrary surface density distributions, and Monte Carlo methods to compute lensing statistics such as point-source lensing cross-sections. Incorporating a variety of magnification bias modes lets us examine different survey limitations in image resolution and flux. We rigorously test the numerical methods for systematic errors and sensitivity to basic assumptions. We also determine the minimum number of viewing angles that must be sampled in order to recover accurate orientation-averaged lensing quantities. We find that for a range of non-isothermal stellar and dark matter density profiles typical of elliptical galaxies, the combined density profile and corresponding lensing properties are surprisingly close to isothermal around the Einstein radius. The converse implication is that constraints from strong lensing and/or stellar kinematics, which are indeed consistent with isothermal models near the Einstein radius, cannot trivially be extrapolated to smaller and larger radii.Comment: 31 pages, 15 figures; paper II at arXiv:0808.2497; accepted for publication in MNRAS; PDF file with full resolution figures at http://www.sns.ias.edu/~glenn/paper1.pd

    LSST Science Book, Version 2.0

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    A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo
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