Fixing financialization in the credit-constrained city     

Sarah Launius 《Urban geography》2013,34(9):1335-1355

The financialization of urban development occurs even under conditions of credit constraint. The paper demonstrates that credit scarcity is an important and under-examined driver of policy improvisation and institutional development. Using the case of Tucson, Arizona, we show that local and extra-local interests overlap and cross-pollinate to produce unique hybrids – geographically specific and contingent institutional forms cultivated by local growth machines to attract outside financial interests. These dynamics are illustrated with a sales-tax-based tax increment financing district that employs “enhanced financings” to attract extra-local sources of debt and equity. We find that the financialization of urban development in the credit-constrained city is not just a process of abstraction, but also of particularization in which extra-local dollars flow through embedded local networks. We conclude with a call for greater attention to the intersections of finance and urban life in “ordinary cities”.  相似文献   

“Is there a bubble to burst?”-college students’ spatial perception of campus and the city,a case study of rhodes college in memphis,TN     

Shaolu Yu  Madalyn Bryant  Emily Messmer  Sophia Tsagronis  Sarah Link 《Urban geography》2013,34(10):1555-1575

ABSTRACT

This paper builds on the study of student geography by critically examining college students’ perceived space of a university campus and the surrounding urban space. Rhodes College is a liberal arts college situated in the city of Memphis. As a campus with a majority white population located in a predominately black city, Rhodes College exists within but often separate from the city. It serves as a perfect case study to investigate how the college students build relationships with the environment within and beyond the campus. By using mental mapping and focus groups, this research unpacks four spatialities that shape college students’ perception of the urban space: (in)activity space, (im)mobility, boundaries, and center. This research demonstrates that student geography can be gendered, classed and racialized. The perceived space is socially constructed, and is reinforced by the lived and material space. Finally, this paper provides implications to facilitate deeper connections between students, the campus, and the city.  相似文献   

Arsenic Control During Aquifer Storage Recovery Cycle Tests in the Floridan Aquifer     

June E. Mirecki  Michael W. Bennett  Marie C. López‐Baláez 《Ground water》2013,51(4):539-549

Implementation of aquifer storage recovery (ASR) for water resource management in Florida is impeded by arsenic mobilization. Arsenic, released by pyrite oxidation during the recharge phase, sometimes results in groundwater concentrations that exceed the 10 µg/L criterion defined in the Safe Drinking Water Act. ASR was proposed as a major storage component for the Comprehensive Everglades Restoration Plan (CERP), in which excess surface water is stored during the wet season, and then distributed during the dry season for ecosystem restoration. To evaluate ASR system performance for CERP goals, three cycle tests were conducted, with extensive water‐quality monitoring in the Upper Floridan Aquifer (UFA) at the Kissimmee River ASR (KRASR) pilot system. During each cycle test, redox evolution from sub‐oxic to sulfate‐reducing conditions occurs in the UFA storage zone, as indicated by decreasing Fe²⁺/H₂S mass ratios. Arsenic, released by pyrite oxidation during recharge, is sequestered during storage and recovery by co‐precipitation with iron sulfide. Mineral saturation indices indicate that amorphous iron oxide (a sorption surface for arsenic) is stable only during oxic and sub‐oxic conditions of the recharge phase, but iron sulfide (which co‐precipitates arsenic) is stable during the sulfate‐reducing conditions of the storage and recovery phases. Resultant arsenic concentrations in recovered water are below the 10 µg/L regulatory criterion during cycle tests 2 and 3. The arsenic sequestration process is appropriate for other ASR systems that recharge treated surface water into a sulfate‐reducing aquifer.  相似文献   

Observations of dugongs at Aldabra Atoll,western Indian Ocean: lagoon habitat mapping and spatial analysis of sighting records     

Sarah M. Hamylton  Annelise B. Hagan  Naomi Doak 《International journal of geographical information science》2013,27(5):839-853

Until recently, it was thought that dugongs (Dugong dugon) were extinct in the Seychelles. However, a collection of sightings at Aldabra Atoll, a World Heritage Site in the Seychelles, has renewed interest in dugong distribution in the western Indian Ocean. This article consolidates the records of dugong sightings held in the Aldabra Research Station library and explores their spatial patterning. The locations of sightings (2001–2009) are plotted onto a high-resolution benthic habitat map of the Aldabra lagoon created by classifying a QuickBird satellite remote-sensing image in January 2009. A spatial cluster detection procedure is applied to point records of sightings to reveal a statistically significant cluster of sightings in the north-west of the lagoon, at Bras Monsieur Clairemont, suggesting a mutual co-existence of dugongs and seagrass beds. A habitat suitability model combines the point data set of dugong sightings within the continuous benthic habitat map and identifies the central western area as containing the most suitable habitat for dugong inside the Aldabra lagoon.  相似文献   

Phases of blowout initiation and stabilization on Padre Island revealed through ground-penetrating radar and remotely sensed imagery     

Mallorie Jewell  Sarah Trimble 《自然地理学》2013,34(6):556-577

Abstract

Blowouts cover a large section of North Padre Island, Texas, and have previously been associated with overgrazing and vehicles driving between the low water line and the toe of the foredune. In the current study, the evolution and migration of 18 blowouts within Padre Island National Seashore are tracked using aerial photographs and satellite images since 1969. Representative active and stabilized trough blowouts are also examined using ground-penetrating radar surveys and remotely sensed imagery to identify the phases of blowout initiation and stabilization between 1969 and 2010. At least five distinct phases can be identified in the radar surfaces and facies of the active blowout, including both the stabilization and reactivation of the blowout throat, whereas only four phases can be identified in the surfaces and facies of a blowout that completely stabilized in 2010. Results suggest that blowout evolution on Padre Island is episodic and is initiated by the opening and closing of the blowout throat during periods with elevated storm surge. The lack of reflectors at depth is evidence that the development of blowouts on Padre Island is a relatively new phenomenon initiated by overgrazing and maintained by compaction of the beach and backshore by vehicles.  相似文献   

Pre‐Glacial Landform Inheritance in a Glaciated Shield Landscape     

Adrian M. Hall  Karin Ebert  Clas Hättestrand 《Geografiska Annaler: Series A, Physical Geography》2013,95(1):33-49

We seek to quantify glacial erosion in a low relief shield landscape in northern Sweden. We use GIS analyses of digital elevation models and field mapping of glacial erosion indicators to explore the geomorphology of three granite areas with the same sets of landforms and of similar relative relief, but with different degrees of glacial streamlining. Area 1, the Parkajoki district, shows no streamlining and so is a type area for negligible glacial erosion. Parkajoki retains many delicate pre‐glacial features, including tors and saprolites with exposure histories of over 1 Myr. Area 2 shows the onset of significant glacial erosion, with the development of glacially streamlined bedrock hills. Area 3 shows extensive glacial streamlining and the development of hill forms such as large crag and tails and roches moutonnées. Preservation of old landforms is almost complete in Area 1, due to repeated covers of cold‐based, non‐erosive ice. In Area 2, streamlined hills appear but sheet joint patterns indicate that the lateral erosion of granite domes needed to form flanking cliffs and to give a streamlined appearance is only of the order of a few tens of metres. The inheritance of large‐scale, pre‐glacial landforms, notably structurally controlled bedrock hills and low relief palaeosurfaces, remains evident even in Area 3, the zone of maximum glacial erosion. Glacial erosion here has been concentrated in valleys, leading to the dissection and loss of area of palaeosurfaces. Semi‐quantitative estimates of glacial erosion on inselbergs and palaeosurfaces and in valleys provide mean totals for glacial erosion of 8 ± 8 m in Area 1 and 27 ± 11 m in Area 3. These estimates support previous views that glacial erosion depths and rates on shields can be low and that pre‐glacial landforms can survive long periods of glaciation, including episodes of wet‐based flow.  相似文献   

River flow regime and snow cover of the Pamir Alay (Central Asia) in a changing climate     

Pierre Chevallier  Bernard Pouyaud  Marie Mojaïsky  Mikhaïl Bolgov  Oliver Olsson  Melanie Bauer 《水文科学杂志》2013,58(8):1491-1506

Abstract

The Vakhsh and Pyandj rivers, main tributaries of the Amu Darya River in the mountainous region of the Pamir Alay, play an important role in the water resources of the Aral Sea basin (Central Asia). In this region, the glaciers and snow cover significantly influence the water cycle and flow regime, which could be strongly modified by climate change. The present study, part of a project funded by the European Commission, analyses the hydrological situation in six benchmark basins covering areas of between 1800 and 8400 km², essentially located in Tajikistan, with a variety of topographical situations, precipitation amounts and glacierized areas. Four types of parameter are discussed: temperature, glaciation, snow cover and river flows. The study is based mainly on a long-time series that ended in the 1990s (with the collapse of the Soviet Union) and on field observations and data collection. In addition, a short, more recent period (May 2000 to May 2002) was examined to better understand the role of snow cover, using scarce monitored data and satellite information. The results confirm the overall homogeneous trend of temperature increase in the mountain range and its impacts on the surface water regime. Concerning the snow cover, significant differences are noted in the location, elevation, orientation and morphology of snow cover in the respective basins. The changes in the river flow regime are regulated by the combination of the snow cover dynamics and the increasing trend of the air temperature.