京津冀城市群土地经济密度时空格局演变与驱动因素分析

[目的]研究2006—2016年京津冀城市群土地经济密度的时空格局演变特征及其驱动机制。[方法]以京津冀城市群153个县区为例,运用空间自相关分析、热点分析、地理探测器等研究方法,对土地经济密度的时空演变规律及其驱动因素进行探讨。[结果](1)2006—2016年京津冀城市群县区和地市的土地经济密度及其发展速度在空间上均呈"东高西低,南高北低"格局,但随时间变化区域差异逐渐缩小;(2)Moran′s I指数由0.013 9上升至0.065 3,表明在空间上存在空间集聚状态,且随时间不断优化,区域一体化趋势逐渐增强;(3)空间集聚特征明显,热点显著区集中于北京、天津等经济优势区,并向四周梯度扩散;(4)人均GDP、当年实际使用外资额、固定资产投资额等经济类因子对土地经济密度的解释力较大,且任意两因子交互后作用力优于单项因子作用力。[结论]可为京津冀城市群土地资源的合理利用和差别化调控提供参考。     

让自然参与设计：一种基于自然演替的 城市自生群落改良设计途径

城市自生群落具有重要的生态服务功能与潜力，但因其外貌不被公众所接受而难以在城市公共空间中应用。将群落生态学和设计学相结合，探索一种介入栽培植物对城市自生群落进行改良，最终形成具有一定美学价值的植物群落的途径。实验以植物群落设计美学原理和种间竞争原理为依据，向已经演替1年的城市自生群落中引入63种栽培植物，按照分层的方式对群落进行改良。3年的观测结果表明，有61.9%的栽培植物可以在城市自生群落中定居并建立优势，能对76.7%的自生植物起到抑制作用，使55.8%的自生植物消失。相比城市自生群落，改良后的群落美观度提高29.4%，公众接受度提高24%，群落的物种丰富度提高至2.29倍。相比一般的人工植物群落，改良后的群落可以节约58.2%的建植成本，降低83.9%的浇水成本和67.8%的除草成本。实验证明改良设计是一种可行的群落设计途径，能有效提高群落的物种丰富度和美学价值，同时让自然参与群落设计过程，实现人与自然的合作。     

气候障碍因子对城市绿化适生树种选择的 影响——以上海世博公园为例

通过对上海近30年的气候因子汇总分析，结合对上 海世博公园主要绿化树种生长状况调查和年度生物量计算，通 过典型相关性分析发现，极端高低温、强风和暴雨等5个气候 因子对树木的生长产生了不同程度的影响，有些因子严重阻碍 了树木的正常生长，成为障碍因子。经过10年的绿化实践验 证，上海世博公园对骨干树种的选择，以乡土树种为主，群落 结构较为稳定，且气候障碍因子对乡土树种的影响较小。在引 种外来树种时，采用气候相似植物区系法，结合植物耐寒、耐 热带图，把种源地划分为2个气候带和3个植物区系，并确定了 最南引种线，成功引种了红花槭等20种观花色叶乔木树种。     

The Familiar Face of the State: Affect,Emotion and Citizen Entitlements in Dehradun,India

Municipal Councillors (MCs) are the ‘familiar face of the state’ in Dehradun, India: the first port of call for citizens seeking to claim entitlements from the state. The way MCs respond to the requests of their constituents is a major factor in the uneven distribution of government welfare and services. This article seeks to contribute to understandings of citizen entitlements by drawing attention to the role of affect and emotion in shaping the interactions between MCs and voters. I examine the ways citizens consciously or unconsciously engender emotions and affective responses, and the effect these have in mobilizing MCs. Attention to the, at times, involuntary nature of these responses suggests a need to go beyond the instrumental and calculating motivations of municipal councillors, to consider the way they are compelled and animated to meet the demands of some citizens, but not of others. The capacity to affect, and the ways one is affected, are tied to the social identities and self-making projects of both the MC and the voter, resulting in an uneven (mal)distribution of state resources. A focus on affective configurations in urban governance thereby reveals heretofore overlooked determinants of unequal access to urban resources and services.     

Contradictions of the Climate-Friendly City: New Perspectives on Eco-Gentrification and Housing Justice

As local governments and corporations promote ‘climate friendliness’, and a low-carbon lifestyle becomes increasingly desirable, more middle- and upper-income urban residents are choosing to live near public transit, on bike- and pedestrian-friendly streets, and in higher-density mixed-use areas. This rejection of classical forms of suburbanization has, in part, increased property values in neighborhoods offering these amenities, displacing lower-income, often non-white, residents. Increased prevalence of creative and technology workers appears to accelerate this trend. We argue that a significant and understudied socio-environmental contradiction also occurs where the actual environmental outcomes of neighborhood transformation may not be what we expect. New research on greenhouse gas emissions shows that more affluent residents have much larger carbon footprints because of their consumption, even when reductions in transportation or building energy emissions are included. We describe an area in Seattle, Washington, the location of Amazon's headquarters, experiencing this contradiction and show a distinct convergence of city investments in low-carbon infrastructure, significant rises in housing prices and decreases in lower-income and non-white residents. We conclude with a discussion of a range of issues that require more attention by scholars interested in housing justice and/or urban sustainability.     

Geographies of Algorithmic Violence: Redlining the Smart City

City governments are embracing data-driven and algorithmic planning to tackle urban problems. Data-driven analytics have an unprecedented capacity to call urban futures into being. At the same time, they can depoliticize planning decisions. I argue that this shift calls urban studies scholars to investigate geographies of algorithmic violence—a repetitive and standardized form of violence that contributes to the racialization of space and spatialization of poverty. This article examines this broader phenomenon through the case of a proprietary market value assessment that is being used to guide development in cities across the United States. The assessment employs an algorithm that helps city officials make critical decisions about which neighborhoods to target for investment, disinvestment and public service upgrades or disconnections. I argue that the racial, infrastructural, and epistemological violence associated with this evaluation can potentially lead to a new kind of municipal redlining. The article brings insights from critical race theory into conversation with critical scholarship on algorithms by analyzing how algorithmic violence works through data-driven planning technologies to depoliticize and leverage power while further entrenching racism and inequality.     

Tent City: Patterns of Informality and the Partitioning of Sacramento

Unsanctioned tent cities are increasing in number in cities throughout the western United States. Scholars explain the phenomenon as homeless people asserting their ‘right to the city’ or as ‘managed marginality’. These explanations capture much of the socio-political relationship between local government and homeless populations, but do not explain the long-term persistence of tent cities and the fluctuating nature of their visibility. A spatial history of informal encampments in Sacramento at three key moments—the founding of the city, the Great Depression and the Great Recession—reveals a long-term ebb and flow of tent cities occupying close-to-the-center, urban vacancies. Urban vacancies arise from the partitioning of the city into specific purposes, places and people, a taken-for-granted perception of how cities should be. The visibility of tent cities disrupts this aesthetic notion of stability and growth as homeless people use the tent to protest their isolation and exclusion.     

Urban Commoning as a Vehicle Between Government Institutions and Informality: Collective Gardening Practices in Tampere and Narva

This article examines the processes of urban commoning and its co-produced features of urbanity, making the claim that, through these processes, informality becomes translated into institutionalized city planning. Commoning is analysed through a comparative study that utilizes contingent features of urbanity and three modalities accommodating the informality–formality meshwork during urban change. The article contributes to research on urban transformations by integrating commons, informality dynamics and the constitution of state institutions. This focus is elaborated with reference to collective gardening practices in the context of two of the less studied European cities, Narva in Estonia and Tampere in Finland. The results of the study indicate that urban commoning takes place through delegating a public mandate and enacting uncertainty, two processes that informalize city government practices. Particular differences appeared in regard to the institutional porosity that enables unregulated spaces of collective gardening to be mobilized as part of urban politics. We argue that networked movements appear as an essential part of the urban logic of action producing meaningful connections in an informal–formal meshwork and bringing together multiple sites in the commoning process.     

Paradigm Shifts in Social Housing after Welfare-State Transformation: Learning from the German Experience

Welfare-state transformation and entrepreneurial urban politics in Western welfare states since the late 1970s have yielded converging trends in the transformation of the dominant Fordist paradigm of social housing in terms of its societal function and institutional and spatial form. In this article I draw from a comparative case study on two cities in Germany to show that the resulting new paradigm is simultaneously shaped by the idiosyncrasies of the country's national housing regime and local housing policies. While German governments have successively limited the societal function of social housing as a legitimate instrument only for addressing exceptional housing crises, local policies on providing and organizing social housing within this framework display significant variation. However, planning and design principles dominating the spatial forms of social housing have been congruent. They may be interpreted as both an expression of the marginalization of social housing within the restructured welfare housing regime and a tool of its implementation according to the logics of entrepreneurial urban politics.