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411.
Maps, created through the collection, assembly, and analysis of spatial data are used to support government planning and decision-making. Traditionally, spatial data used to create maps are collected, controlled, and disseminated by government, although over time, this role has shifted. This shift has been driven by the availability of alternate sources of data collected by private sector companies, and data contributed by volunteers to open mapping platforms, such as OpenStreetMap. In theorizing this shift, we provide examples of how governments use data sovereignty as a tool to shape spatial data collection, use, and sharing. We frame four models of how governments may navigate shifting spatial data sovereignty regimes; first, with government retaining complete control over data collection; second, with government contracting a third party to provide specific data collection services, but with data ownership and dissemination responsibilities resting with government; third, with government purchasing data under terms of access set by third party data collectors, who disseminate data to several parties, and finally, with government retreating from or relinquishing data sovereignty altogether. Within this rapidly changing landscape of data providers, we propose that governments must consider how to address data sovereignty concerns to retain their ability to control data use in the public interest.  相似文献   
412.
In the Northeastern U.S., salt marsh area is in decline. Habitat change analysis has revealed fragmentation, displacement of high marsh by low marsh species, and marsh drowning, while development of adjacent uplands limits upslope migration. Measures of marsh vegetation loss for eight sites in Rhode Island and New York between ca.1970 and 2011 indicate that substantial loss has occurred over past decades, with higher loss rates found for lower elevation salt marshes. Using inundation experiments, field surveys, and LiDAR datasets, we developed an elevation-productivity relationship for Spartina alterniflora specific to the U.S. Northeast, and located current salt marsh orthometric heights on this curve. We estimate that 87 % of Northeastern salt marshes are located at elevations where growth is limited by inundation. By manipulating water column nutrients, precipitation, and elevation, we further found that altered precipitation regime was associated with significant reductions in biomass, and that nutrient enrichment adversely impacts organic matter accumulation and peat formation. These results provide evidence that Northeastern U.S. marshes are vulnerable to the effects of accelerated sea level rise, and that neither precipitation changes, nor cultural eutrophication, will contribute positively to long-term salt marsh survival.  相似文献   
413.
Patterns of social interaction influence how knowledge is generated, communicated, and applied. Theories of social capital and organizational learning suggest that interactions within disciplinary or functional groups foster communication of knowledge, whereas interactions across groups foster generation of new knowledge. We used social network analysis to examine patterns of social interaction reported in survey data from scientists and managers who work on fish and fire issues. We found that few fish and fire scientists and managers interact with one another, suggesting low bridging social capital and thus, limited opportunity for generation of new knowledge. We also found that although interaction occurs among scientists—suggesting modest bonding social capital—few managers interact with other managers, indicating limited opportunity for communication of scientific knowledge for the purposes of application. We discuss constraints and opportunities for organizational learning evident in these patterns of social interaction among fish and fire scientists and managers.  相似文献   
414.
Mortality from extreme heat is a leading cause of weather-related fatality, which is expected to increase in frequency with future climate scenarios. This study examines the spatiotemporal variations in heat-related health risk in three Midwestern cities in the USA between the years 1990 to 2010; cities include Chicago, Illinois, Indianapolis, IN and Dayton, OH. In order to examine these variations, we utilize the recently developed extreme heat vulnerability index (EHVI) that uses a principal components solution to vulnerability. The EHVI incorporates data from the US Decadal Census and remotely sensed variables to determine heat-related vulnerability at an intra-urban level (census block group). The results demonstrate significant spatiotemporal variations in heat health risk within the cities involved.  相似文献   
415.
This article suggests a framework for incorporating and communicating local perceptions of hurricane risk into policymaking through a case study conducted at El Zapotito commune in the State of Veracruz, Mexico. The authors constructed a geographical information system (GIS)-based model to quantify and spatially assess specific household-level vulnerabilities from information generated through interviews. This research developed a household vulnerability index applied to a participatory GIS to map vulnerability to hurricane hazard. The results indicate that infrastructural weaknesses are the most important factor contributing to vulnerability, explaining on their own 72.2% of the variation in the vulnerability patterns. These findings are corroborated by a vulnerability and capacity assessment (VCA), which shows that the community lacks strategies to cope with unsafe housing. It is suggested that linking community participation with modern techniques to analyse risk can empower communities and mobilise their capacities to address very specific vulnerabilities.  相似文献   
416.
To assess threats to endangered species, it is critical to establish baselines for contaminant concentrations that may have detrimental consequences to individuals or populations. We measured contaminants in blubber and fat from dead leatherback turtles and established baselines in blood and eggs in nesting turtles. In fat, blubber, blood and eggs, the predominant PCBs were 153 + 132, 187 + 182, 138 + 163, 118, and 180 + 193. Total PCBs, 4,4′-DDE, total PBDEs and total chlordanes were significantly and positively correlated between blood and eggs, suggesting maternal transfer. Significant positive relationships also existed between fat and blubber in stranded leatherbacks. Less lipophilic PCBs appeared to more readily transfer from females to their eggs. PBDE profiles in the four tissues were similar to other wildlife populations but different from some turtle studies. Concentrations were lower than those shown to have acute toxic effects in other aquatic reptiles, but may have sub-lethal effects on hatchling body condition and health.  相似文献   
417.
418.
We investigate the degassing of volatile heavy metals from natural basalt and dacite and synthetic rhyolite melts doped with Bi, Pb, Tl, Au, Re, Sb, Sn, Cd, Mo, As, Cu in Pt capsules over a range of temperatures (1200-1430 °C) exposed to air at 0.1 MPa. We also investigated the effects of ligands on degassing by adding known concentrations of Cl and S. During the experiments concentration gradients normal to the melt/gas interface arose for the trace metals Au, Tl, As, Cd, Re, Bi and Pb, as shown by measurements by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) on the quenched glasses. In contrast, erratic concentration gradients occurred for Cu, Mo, Sn, Sb due to the development of compositional cords in the glass for those elements. The diffusivities for Au, Tl, As, Cd, Re, Bi and Pb (in decreasing order of volatility) followed an Arrhenius relationship with log D at 1260 °C varying from −12 to −17. The addition of Cl and S were shown to increase by two-to five-fold the volatilities of all metals, with S having a more profound effect. Diffusivities from the experiments were applied in a bubble growth model to examine the behavior of Tl and Pb in volcanic gases. The Tl/Pb ratio in gases shows much greater variation than can be explained by partitioning and magma composition alone, with diffusion serving to drastically enrich or deplete the Tl/Pb of gases to values significantly different from that of the melt.  相似文献   
419.
Populations of the American horseshoe crab (Limulus polyphemus) differ in broad areas of their biology. We observed a non-harvested, marked Florida Gulf coast population during their spring spawning (March–May) in 11 years across a 17-year period (1992–2009). Long-term changes occurred in the number of spawning pairs: the population was stable from 1992 to 2000 but increased markedly after 2000. Short-term variation in numbers of spawning pairs, unpaired females, unpaired males, and operational sex ratios was explained by changes over the season and during each week of spring tides and by differences in actual (not predicted) maximum high tide height. Wind direction strongly affected tidal inundation and the number of spawning horseshoe crabs. Tagging individuals revealed that females returned to the nesting beach less often than males and most females were re-sighted only within 1 week of spring tides. No animals were seen across more than 6 years. Implications for management are discussed.  相似文献   
420.
The Great Barrier Reef Outlook Report 2009 was the first produced in response to a newly legislated requirement for five-yearly reports on the status of and outlook for the Great Barrier Reef. It adopted an ecosystem approach, assessing all habitats and species, ecosystem processes and major uses. By then considering the factors affecting the ecosystem, coupled with an assessment of management effectiveness, it provided a risk-based forward-looking projection for the ecosystem. Rarely has such a comprehensive, ecosystem-based report been produced to guide government action. With no pre-determined path to follow for interpreting the legislative requirements, the Great Barrier Reef Marine Park Authority (GBRMPA) developed a repeatable structure and method for Great Barrier Reef Outlook Reports that impartially and consistently considers the evidence and clearly presents the findings. The GBRMPA worked closely with relevant Australian and Queensland Government agencies as well as researchers, industry representatives and the community while developing the report. That such a report must be produced every five years allows an overview of the effectiveness of management responses to be regularly assessed. It also provides a transparent means of highlighting and tracking emerging risks facing the Great Barrier Reef.  相似文献   
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