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181.
Age determinations of bivalve shells indicate that Bockfjorden, a fjord in north-western Spitsbergen, Svalbard, was deglaciated shortly before 10 Kya, and that the upper marine limit in this area, with an altitude of about 50 m a.s.l., has the same age. During most of the Holocene, the glaciers in Bockfjorden were less extensive than they are today. Their maximum Holocene extension occurred during the Little Ice Age. The initial shoreline emergence after the deglaciation was rapid, and former shorelines younger than 8.5 Ky are below the present sea level. A mid-Holocene transgression of the sea is traced as well as a transgression during the last thousand years. 相似文献
182.
Richard J. T. Klein Siri E. H. Eriksen Lars Otto Næss Anne Hammill Thomas M. Tanner Carmenza Robledo Karen L. O’Brien 《Climatic change》2007,84(1):23-44
The need to mainstream adaptation to climate change into development planning and ongoing sectoral decision-making is increasingly
recognised, and several bilateral and multilateral development agencies are starting to take an interest. Over the past years
at least six development agencies have screened their project portfolios, generally with two goals in mind: (1) to ascertain
the extent to which existing development projects already consider climate risks or address vulnerability to climate variability
and change, and (2) to identify opportunities for incorporating climate change explicitly into future projects. As each portfolio
screening was conducted independently, the broader lessons emerging from the screenings have not been systematically analysed.
In this paper we assess the screening activities to date, focusing on both the results and the methods applied. Based on this
assessment we identify opportunities for development agencies to expand their current focus on the links between climate and
development. Most agencies already consider climate change as a real but uncertain threat to future development, but they
have given less thought to how different development patterns might affect vulnerability to climate change. The screenings
undertaken have shown the need to take a comprehensive approach to adaptation and its integration into development planning
and sectoral decision-making, and a number of policy initiatives have been taken to promote such integration. We provide some
initial guidance as to how portfolio screening can be carried out in a way that would allow agencies to assess systematically
the relevance of climate change to their ongoing and planned development projects. 相似文献
183.
184.
Talebi Hassan Mueller Ute Peeters Luk J. M. Otto Alex de Caritat Patrice Tolosana-Delgado Raimon van den Boogaart K. Gerald 《Mathematical Geosciences》2022,54(3):593-621
Mathematical Geosciences - Mineral deposits are metal enrichment anomalies, occurring as local manifestations of the interplay between various geological processes that operate at a wide range of... 相似文献
185.
Barend Köbben Rolf De By Theodor Foerster Otto Huisman Rob Lemmens Javier Morales 《Transactions in GIS》2010,14(Z1):25-37
ITC, the Faculty of Geo–Information Science and Earth Observation of the University of Twente, is an institute that aims at capacity building and institutional development, specifically in developing countries. In our Geoinformatics curriculum, we emphasise two principles. The first addresses the systematics of purposeful spatial data production and uptake into computerised systems; the second addresses the methodical construction of these computerised systems, applying principles of model – driven architecture, formal specification and transformational design of SDI nodes. The term Spatial Data Infrastructure (SDI) usually denotes large, complex systems, but its principles can also be applied in simple and cost–effective ways. This approach we have called SDIlight and it is of particular interest to our students that come from developing countries. We work with and build a software stack consisting of free and open source components. To achieve interoperability, we emphasise the use of open standards from the Open Geospatial Consortium and others. In this paper, we explain how our students apply the SDIlight approach in the GeoinformaticsMaster degree course. An important part of that course is a Case Study Application Building & Programming, in which students apply their knowledge in a ‘real–world’ project, with a focus on geo–information engineering skills. We conclude with a section that evaluates the effectiveness of using the SDIlight concept in teaching our Geoinformatics Master, and on the more general applicability of the methodology. 相似文献
186.
Treistman Felipe Maceira Maria Elvira Pieiro Penna Dbora Dias Jardim Damzio Jorge Machado Rotunno Filho Otto Corra 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(2):331-353
Stochastic Environmental Research and Risk Assessment - The Brazilian Interconnected Power System is hydro dominated and characterized by large reservoirs presenting multi-year regulation... 相似文献
187.
Geminids and Quadrantids are probably observed for only about 100 years. Due to perturbations of their orbits rapid variations occur. A change in the Geminid rate profile can not be found from observations. Observations of Geminids and Quadrantids from Arbeitskreis Meteore are compared with Perseid results. Around their activity peaks we find an increasing number of bright meteors. At the same time the population index r decreases for Perseids and Quadrantids, while it increases for Geminids. From this behaviour we estimate the increase of the number density to fainter magnitude classes for the three showers. 相似文献
188.
Dispersant Use and a Bioremediation Strategy as Alternate Means of Reducing Impacts of Large Oil Spills on Mangroves: The Gladstone Field Trials 总被引:2,自引:0,他引:2
Norman C Duke Kathryn A Burns Richard P.J Swannell Otto Dalhaus Roland J Rupp 《Marine pollution bulletin》2000,41(7-12):403-412
Over a three-year period (1995–1998), we studied short-term effects of dispersant use and a bioremediation strategy in two consecutive field trials in sub-tropical Australian mangroves. In each case, weathered oil was applied, and a large spill simulated, in mature Rhizophora stylosa trees around 4–9 m tall. In the first trial, we used Gippsland light crude oil with or without dispersant, Corexit 9527. In the second, a bioremediation strategy followed application of Gippsland oil or Bunker C fuel oil. Bioremediation involved forced aeration with supplemental application of nutrients. Dispersant use had an overall positive benefit shown as reduced tree mortality. By contrast, there was no apparent reduction in mortality of trees with bioremediation. However, one year after oiling, leaf densities of surviving trees were greater in bioremediation plots than in controls, and less in oil-only plots. These and other results have been incorporated into spill response management strategies in Australia. 相似文献
189.
A three-stage vertical-flow thermal gradient vapour diffusion chamber for the fast, continuous measurement of the number concentration of cloud condensation nuclei (CCN) at three different water vapour supersaturations was constructed. CCN are monitored by imaging cloud droplets in the chamber with a CCD-camera. The counting of droplets and the control of all instrumental parameters are computerized. The instrument was calibrated with NaCl-aerosols, and was successfully operated in the field. Data from 2 weeks of field measurements at an island in the North Sea are presented. 相似文献
190.
Edgar L. Andreas Reginald J. Hill James R. Gosz Douglas I. Moore William D. Otto Achanta D. Sarma 《Boundary-Layer Meteorology》1998,86(3):409-420
From a set of turbulence data collected with a three-axis sonic anemometer/thermometer and described in a companion paper, we simulate the eddy-accumulation process for sensible heat and momentum fluxes. The resulting eddy-accumulation coefficient for momentum clearly depends on surface-layer stability; at neutral stability, its value is 0.63. On supplementing the scalar eddy-accumulation coefficients that we derive from our sensible heat flux data with values of sensible and latent heat flux coefficients reported by Businger and Oncley, we also find that scalar eddy-accumulation coefficients depend on stability, though more weakly than does the momentum coefficient. The coefficients for sensible and latent heat show no significant difference; we, thus, fit them with one function of stability whose value is 0.52 for neutral stratification. 相似文献