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排序方式: 共有505条查询结果,搜索用时 283 毫秒
91.
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93.
Two new mites from the rocky shore of North Auckland 总被引:1,自引:1,他引:0
Malcolm Luxton 《新西兰海洋与淡水研究杂志》2013,47(1):76-87
Hydrogamasus kensleri n.sp. and Fortuynia elamellata n.sp. are described from rock crevices on the upper shore at three localities in North Auckland. The taxonomic relationships of Fortuynia, and the zoogeographical relationships of the known littoral cryptostigmatic mites of New Zealand are briefly discussed. 相似文献
94.
Christian Christiansen Dan Bowman 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):28-31
Christiansen, C. & Bowman, D.: Sea-level changes, coastal dune building and sand drift, North-Western Jutland, Denmark. Geografisk Tidsskrift 86: 28–31. Copenhagen, June 1986. Two main models linking dune building and sea level changes have so far been proposed. Application of the low sea level model suggests that the major Danish dune building period from 1550 to 1750 need not necessarily be the result of human activity. The dune building period is probably related to a low sea level and the reworking of exposed shallow marine sand. 相似文献
95.
Elizabeth Holcombe Sarah Smith Edmund Wright Malcolm G. Anderson 《Natural Hazards》2012,61(2):351-385
Despite the recognition of the need for mitigation approaches to landslide risk in developing countries, the delivery of ‘on-the-ground’
measures is rarely undertaken. With respect to other ‘natural’ hazards, it is widely reported that mitigation can pay. However,
the lack of such an evidence base in relation to landslides in developing countries hinders advocacy amongst decision makers
for expenditure on ex-ante measures. This research addresses these limitations directly by developing and applying an integrated
risk assessment and cost–benefit analysis of physical landslide mitigation measures implemented in an unplanned community
in the Eastern Caribbean. In order to quantify the level of landslide risk reduction achieved, landslide hazard and vulnerability
were modelled (before and after the intervention), and project costs, direct and indirect benefits were monetised. It is shown
that the probability of landslide occurrence has been substantially reduced by implementing surface-water drainage measures
and that the benefits of the project outweigh the costs by a ratio of 2.7–1. This paper adds to the evidence base that ‘mitigation
pays’ with respect to landslide risk in the most vulnerable communities—thus strengthening the argument for ex-ante measures.
This integrated project evaluation methodology should be suitable for adoption as part of the community-based landslide mitigation
project cycle, and it is hoped that this resource, and the results of this study, will stimulate further such programmes. 相似文献
96.
Duncan A. Christie Jos�� A. Boninsegna Malcolm K. Cleaveland Antonio Lara Carlos Le Quesne Mariano S. Morales Manfred Mudelsee David W. Stahle Ricardo Villalba 《Climate Dynamics》2011,36(7-8):1505-1521
The Andes Cordillera acts as regional ??Water Towers?? for several countries and encompasses a wide range of ecosystems and climates. Several hydroclimatic changes have been described for portions of the Andes during recent years, including glacier retreat, negative precipitation trends, an elevation rise in the 0° isotherm, and changes in regional streamflow regimes. The Temperate-Mediterranean transition (TMT) zone of the Andes (35.5°?C39.5°S) is particularly at risk to climate change because it is a biodiversity hotspot with heavy human population pressure on water resources. In this paper we utilize a new tree-ring network of Austrocedrus chilensis to reconstruct past variations in regional moisture in the TMT of the Andes by means of the Palmer Drought Severity Index (PDSI). The reconstruction covers the past 657?years and captures interannual to decadal scales of variability in late spring?Cearly summer PDSI. These changes are related to the north?Csouth oscillations in moisture conditions between the Mediterranean and Temperate climates of the Andes as a consequence of the latitudinal position of the storm tracks forced by large-scale circulation modes. Kernel estimation of occurrence rates reveals an unprecedented increment of severe and extreme drought events during the last century in the context of the previous six centuries. Moisture conditions in our study region are linked to tropical and high-latitude ocean-atmospheric forcing, with PDSI positively related to Ni?o-3.4 SST during spring and strongly negatively correlated with the Antarctic Oscillation (AAO) during summer. Geopotential anomaly maps at 500-hPa show that extreme dry years are tightly associated with negative height anomalies in the Ross?CAmundsen Seas, in concordance with the strong negative relationship between PDSI and AAO. The twentieth century increase in extreme drought events in the TMT may not be related to ENSO but to the positive AAO trend during late-spring and summer resulting from a gradual poleward shift of the mid-latitude storm tracks. This first PDSI reconstruction for South America demonstrates the highly significant hindcast skill of A. chilensis as an aridity proxy. 相似文献
97.
Developing coastal adaptation to climate change in the New York City infrastructure-shed: process, approach, tools, and strategies 总被引:1,自引:0,他引:1
Cynthia Rosenzweig William D. Solecki Reginald Blake Malcolm Bowman Craig Faris Vivien Gornitz Radley Horton Klaus Jacob Alice LeBlanc Robin Leichenko Megan Linkin David Major Megan O��Grady Lesley Patrick Edna Sussman Gary Yohe Rae Zimmerman 《Climatic change》2011,106(1):93-127
While current rates of sea level rise and associated coastal flooding in the New York City region appear to be manageable by stakeholders responsible for communications, energy, transportation, and water infrastructure, projections for sea level rise and associated flooding in the future, especially those associated with rapid icemelt of the Greenland and West Antarctic Icesheets, may be outside the range of current capacity because extreme events might cause flooding beyond today??s planning and preparedness regimes. This paper describes the comprehensive process, approach, and tools for adaptation developed by the New York City Panel on Climate Change (NPCC) in conjunction with the region??s stakeholders who manage its critical infrastructure, much of which lies near the coast. It presents the adaptation framework and the sea-level rise and storm projections related to coastal risks developed through the stakeholder process. Climate change adaptation planning in New York City is characterized by a multi-jurisdictional stakeholder?Cscientist process, state-of-the-art scientific projections and mapping, and development of adaptation strategies based on a risk-management approach. 相似文献
98.
99.
Esler D Ballachey BE Trust KA Iverson SA Reed JA Miles AK Henderson JD Woodin BR Stegeman JJ McAdie M Mulcahy DM Wilson BW 《Marine pollution bulletin》2011,62(3):609-614
We examined hepatic EROD activity, as an indicator of CYP1A induction, in Barrow’s goldeneyes captured in areas oiled during the 1989 Exxon Valdez spill and those from nearby unoiled areas. We found that average EROD activity differed between areas during 2005, although the magnitude of the difference was reduced relative to a previous study from 1996/1997, and we found that areas did not differ by 2009. Similarly, we found that the proportion of individuals captured from oiled areas with elevated EROD activity (?2 times unoiled average) declined from 41% in winter 1996/1997 to 10% in 2005 and 15% in 2009. This work adds to a body of literature describing the timelines over which vertebrates were exposed to residual Exxon Valdez oil and indicates that, for Barrow’s goldeneyes in Prince William Sound, exposure persisted for many years with evidence of substantially reduced exposure by 2 decades after the spill. 相似文献
100.