空间不匹配带来城市收缩的三重逻辑——制度空间位移、政策空间悖论与行为空间失衡

自改革开放以来，持续了近40年的飞速发展和规模扩张，我国的城市发展步入了“后城市化”时代。“快速扩张下”的城市收缩现象越来越引起理论和实务层面的关注，其中空间层面的资源不匹配和不协调是带来城市收缩的重要原因。基于“空间—行为”互动理论，尝试从“制度—政策—行为”层面的空间不匹配，解释城市收缩的逻辑归因。其中，制度空间通过“经济体制转型”和“社会结构变迁”，带来收缩城市在空间和社会上的两极分化；政策空间基于政治体制、社会政策带来城市发展的不平衡；行为空间嵌入个体、群体、家庭行为中，通过职住分离、就业环境等带来个体“空间—行为”的不匹配。最后，提出深化经济制度改革，促进收缩型城市再“更新”、关照区域政策平衡，扩大收缩型城市的公共服务供给、坚持“以人为本”，让城市成为“人”的“家”等治理导向与政策尝试。     

Numerical Modeling of a Church Nave Wall Subjected to Differential Settlements: Soil-Structure Interaction,Time-Dependence and Sensitivity Analysis

ABSTRACT

Historic masonry structures are particularly sensitive to differential soil settlements. These settlements may be caused by deformable soil, shallow or inadequate foundation, structural additions in the building and changes in the underground water table due to the large-scale land use change in urban areas.

This paper deals with the numerical modeling of a church nave wall subjected to differential settlement caused by a combination of the above factors. The building in question, the church of Saint Jacob in Leuven, has suffered extensive damage caused by centuries-long settlement. A numerical simulation campaign is carried out in order to reproduce and interpret the cracking damage observed in the building.

The numerical analyses are based on material and soil property determination, the monitoring of settlement in the church over an extended period of time and soil-structure interaction. A sensitivity study is carried out, focused on the effect of material parameters on the response in terms of settlement magnitude and crack width and extent. Soil consolidation over time is considered through an analytical approach. The numerical results are compared with the in-situ observed damage and with an analytical damage prediction model.     

Spatial interaction and security: a review and case study of the Syrian refugee crisis

ABSTRACT

Sir Alan Wilson's ideas have been highly influential in the modelling of phenomena including migration, transport and economics. Latterly, research has explored the application of similar ideas to new problems at larger scales. Many of these studies relate to global challenges with significant policy implications. Here, we present an example in the form of original empirical work concerning forced migration associated with the current Syrian refugee crisis. We employ a spatial interaction framework to examine the flows of migrants fleeing Syria and the characteristics which influence their choice of destination country. In line with the broader literature, we find that shorter distances, economic prosperity, and cultural similarity (e.g. shared language) attract forced migrants, as does the probability of being granted asylum; a finding with potential implications for policy. Contrary to expectation, we find little influence for levels of security in potential host nations (e.g. absence of terrorism).     

Integrating Local and Regional in Pre-Contact Hawaiian Agriculture at Kahuku,Hawai‘i Island

ABSTRACT

The agricultural systems of the Hawaiian archipelago were some of the most intensive in the Pacific and this scale of intensity is well illustrated by the large agricultural landscapes of leeward Hawai‘i Island. Previous research in the area has centred on understanding the relationship between agriculture, political process, and large-scale environmental conditions. Much of this research has been oriented at the regional level, privileging discussion of elite management and oversight, with only limited investigation exploring farmer-centric adaptation at local scales. In this paper, we assess the integration of local and regional processes in Hawaiian agriculture using recent paired archaeological and ecological data from the Ka‘ū Field System as a case study. We demonstrate the presence of both general patterns previously identified in the archipelago and particular adaptations to the local environment of Kahuku ahupua‘a. In particular, we highlight targeted infrastructural developments that allowed for cultivation of what would otherwise be a difficult cultivation medium within the confines of a larger, likely regionally organised, field system constrained by general soil biogeochemical thresholds. We argue that such investigations provide an increased understanding on how these large-scale agricultural landscapes were formed by integration at multiple social and spatial scales.     

Identity,social interaction,and networks in the region of Wisconsin’s Holyland

ABSTRACT

This paper focuses on how a sense of identity, social interaction, and networks contribute to the construction and maintenance of regions. Using Wisconsin’s Holyland as a case study, we conducted fieldwork, collected primary data from residents through a survey, and utilized social network analysis (SNA) to determine how it is defined as a vernacular and functional region. While there appeared to be consensus regarding the key defining characteristics of Wisconsin’s Holyland on the surface, our data analysis revealed contrasting perceptions and definitions of the region. In addition, a SNA of self-reported social interactions by residents highlighted a complex cultural geography through the appearance of subregions and expanded borders of the region overall.