Researching the city edited by Kevin Ward (ed.), Sage,Thousand Oaks,CA, 2014. 167 pp. ISBN 978‐1‐4462‐0211‐1.     

Helen Fitt  Heather Cohen 《New Zealand geographer》2014,70(2):149-150

  相似文献   

Environmental Correlates of Growth and Stable Isotopes in Intertidal Species Along an Estuarine Fjord     

Jennifer L. Ruesink  Alan C. Trimble  Helen Berry  Amy G. Sprenger  Megan N. Dethier 《Estuaries and Coasts》2014,37(1):149-159

Production and resource use by intertidal taxa were studied in the estuarine fjord of Puget Sound, Washington, USA. Along nearly 100 km, salinity is similar, and intertidal habitat and immersion time were kept consistent, thus allowing a focus on other environmental variables such as temperature and resource availability that could influence growth. Primary producers (ulvoid and fucoid macroalgae) and suspension feeders (oysters and barnacles) were transplanted on three beaches in each of three regions and assessed for individual-level growth, carbon and nitrogen ratios, and stable isotopes. In most transplants, δ¹³C and C/N showed no regional variation but δ¹⁵N was enriched up-estuary. Among environmental variables, chlorophyll a, total suspended solids, and particulate organic matter had small and/or inconsistent regional variation, but temperature was higher up-estuary. For the most intensively studied species (Pacific oyster, Crassostrea gigas) transplanted four times over 2 years, seasonal and regional variation in growth were best predicted by temperature rather than resource availability. Growth rates continued to increase into Totten Inlet, a shallow finger inlet at the head of Puget Sound. As indicators of environmental conditions, the growth and tissue chemistry of intertidal study taxa affirm that sources and amounts of resources show no strong gradients along this estuarine fjord, and they also support temperature as a key factor for performance, with species-specific responses. Higher temperatures may also have community-level impacts, given prior evidence linking beach temperatures to reduced intertidal diversity and biomass into Puget Sound.  相似文献   

Disaster resilience in a flood-impacted rural Australian town     

Helen J. Boon 《Natural Hazards》2014,71(1):683-701

This paper reports exploratory research conducted in a flood-impacted rural Australian town to identify the factors which residents perceived as supporting community resilience to disaster. There is a gap in this research area centred in the Australian disaster context. Since Australia is predicted to be highly impacted by the effects of climate change in the form of an increased incidence of flooding, an urgent need exists to examine the factors that confer resilience to disaster-impacted localities to inform suitable disaster mitigation and adaptation policies for the future. Because of the complexity of community resilience and its interrelationship with individual resilience, a multi-method approach was used: a demographic study to assess community stability and functioning before and after the flood disaster, focus group interviews to obtain from community members their views on what supported them and their community resilience and a survey to generalise the interview findings. Our operating hypothesis was that individuals remaining in the town post-flood were likely to be resilient to the flood disaster. The demographic study results pointed to a resilient community after the floods as they reflected stability in population numbers and socio-economic indicators. The interviews and survey showed that individual resilience was promoted by social connectedness and a sense of place, a factor that was also negatively linked to the desire to relocate from the community. The use of structural equation modelling of our results provided verification of prior research findings about the role of sense of place in supporting individuals’ resilience. Results are discussed in the context of future climate change adaptation policy.  相似文献   

Agriculture,community, river eutrophication and the Water Framework Directive     

Colin Neal  Helen P. Jarvie 《水文研究》2005,19(9):1895-1901

  相似文献   

EXPLORING SPATIAL FAMILIARITY*     

Nathan Gale  Reginald G. Golledge  William C. Halperin  Helen Couclelis 《The Professional geographer》1990,42(3):299-313

Spatial familiarity is a natural language concept that has no well-defined technical interpretation. We explore here some possible dimensions of the concept, provide subjective measurements of the dimensions, and evaluate their independence. The four dimensions examined are locational knowledge, visual recognition, name identification, and interaction frequency. We suggest that both cognitive and behavioral dimensions are embedded in the concept of spatial familiarity and must be part of the meaning of the concept and of any attempt to make it operational.  相似文献   

Improved Visualization Using a Fusion Technique Based on KNN Matting of Remotely Sensed Images     

Ablin Rajathurai  Helen Sulochana Chellakkon 《Journal of the Indian Society of Remote Sensing》2018,46(2):179-187

  相似文献   

An experimental study of partial melting and fractional crystallization on the HED parent body          下载免费PDF全文

Helen O. Ashcroft  Bernard J. Wood 《Meteoritics & planetary science》2015,50(11):1912-1924

We have performed an experimental and modeling study of the partial melting behavior of the HED parent body and of the fractional crystallization of liquids derived from its mantle. We estimated the mantle composition by assuming chondritic ratios of refractory lithophile elements, adjusting the Mg# and core size to match the density and moment of inertia of Vesta, and the compositions of Mg‐rich olivines found in diogenites. The liquidus of a mantle with Mg# (=100*[Mg/(Mg+Fe)]) 80 is ~1625 °C and, under equilibrium conditions, the melt crystallizes olivine alone until it is joined by orthopyroxene at 1350 °C. We synthesized the melt from our 1350 °C experiment and simulated its fractional crystallization path. Orthopyroxene crystallizes until it is replaced by pigeonite at 1200 °C. Liquids become eucritic and crystal assemblages resemble diogenites below 1250 °C. MELTS correctly predicts the olivine liquidus but overestimates the orthopyroxene liquidus by ~70 °C. Predicted melt compositions are in reasonable agreement with those generated experimentally. We used MELTS to determine that the range of mantle compositions that can produce eucritic liquids and diogenitic solids in a magma ocean model is Mg# 75–80 (with chondritic ratios of refractory elements). A mantle with Mg# ~ 70 can produce eucrites and diogenites through sequential partial melting.  相似文献   

A Relationship Between Transition Region Brightenings,Abundances, and Magnetic Topology     

Fletcher  Lyndsay  López Fuentes  Marcelo C.  Mandrini  Cristina H.  Schmieder  Brigitte  Démoulin  Pascal  Mason  Helen E.  Young  Peter R.  Nitta  Nariaki 《Solar physics》2001,203(2):255-287

We present multi-instrument observations of active region (AR) 8048, made between 3 June and 5 June 1997, as part of the SOHO Joint Observing Program 33. This AR has a sigmoid-like global shape and undergoes transient brightenings in both soft X-rays and transition region (TR) lines. We compute a magneto-hydrostatic model of the AR magnetic field, using as boundary condition the photospheric observations of SOHO/MDI. The computed large-scale magnetic field lines show that the large-scale sigmoid is formed by two sets of coronal loops. Shorter loops, associated with the core of the SXT emission, coincide with the loops observed in the hotter CDS lines. These loops reveal a gradient of temperature, from 2 MK at the top to 1 MK at the ends. The field lines most closely matching these hot loops extend along the quasi-separatrix layers (QSLs) of the computed coronal field. The TR brightenings observed with SOHO/CDS can also be associated with the magnetic field topology, both QSL intersections with the photosphere, and places where separatrices issuing from bald patches (sites where field lines coming from the corona are tangent to the photosphere) intersect the photosphere. There are, furthermore, suggestions that the element abundances measured in the TR may depend on the type of topological structure present. Typically, the TR brightenings associated with QSLs have coronal abundances, while those associated with BP separatrices have abundances closer to photospheric values. We suggest that this difference is due to the location and manner in which magnetic reconnection occurs in two different topological structures. Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1023/A:1013302317042  相似文献   

Survivorship of coral juveniles in a fish farm environment   总被引：1，自引：0，他引：1  

Villanueva RD  Yap HT  Montaño MN 《Marine pollution bulletin》2005,51(5-7):580-589

Intensive fish farming is an emerging coastal activity that can potentially enhance sedimentation and promote eutrophication in fringing coral reefs. Here, we investigate the effect of fish farm effluent on the juvenile survivorship of the reef-building coral Seriatopora caliendrum. One-month old juvenile corals (on terracotta tiles) were deployed in fish farm and reference (reef) sites in Bolinao, the Philippines at a depth of 2m. After forty days, no survivor was recovered in the fish farm, while survivorship was low (11%) in the reference site, with the survivors' growth rate at 3.3polypsmo(-1) or 1.3mm(2)mo(-1). The fish farm deployed tiles were covered with muddy sediment and were colonized by barnacles, whereas those in the reference site were overgrown by a short stand of filamentous macroalgae. Environmental monitoring revealed higher nutrient levels (ammonia and phosphate), sedimentation rate, and organic matter flux, as well as diminished water transparency and dissolved oxygen levels in the fish farm compared to the reference site. Hence, intensive fish farming offers a suite of physical, chemical and biological modifications of the coastal marine environment which have a detrimental effect on the survivorship of coral juveniles.  相似文献   

The solar particle event of July 16–19, 1966 and its possible association with a flare on the invisible solar hemisphere     

Helen W. Dodson  E. Ruth Hedeman  Stephen W. Kahler  Robert P. Lin 《Solar physics》1969,6(2):294-303

An energetic solar proton and electron event was observed by particle detectors aboard Explorer 33 (AIMP-1) and OGO-3 during the period July 16–19, 1966. Optical and radio observations of the sun suggest that these particles were produced by a flare which may have occurred on July 16 near the central meridian of the invisible hemisphere. The active region to which the flare is assigned is known to have produced the energetic particle events of July 7 and 28, 1966. The propagation of the particles in the July 16–19 event over the 180° extent of solar longitude from the flare to the earth is discussed, and it is concluded that there must exist a means of rapidly distributing energetic particles over a large area of the sun. Several possible mechanisms are suggested.  相似文献