Farmers’ assessments of private adaptive measures to climate change and influential factors: a study in the Mekong Delta,Vietnam   总被引：2，自引：0，他引：2  

Hoa Le Dang  Elton Li  Ian Nuberg  Johan Bruwer 《Natural Hazards》2014,71(1):385-401

Adaptation to climate change in agricultural settings depends on understanding farmers’ perceptions of the nature of climate change, their agency in adapting and the efficacy of adaptive measures themselves. Such knowledge can improve mitigation and adaptation strategies. This study addresses the limited understanding of how farmers appraise their private adaptive measures and influential factors. It uses data from structured interviews with 598 rice farmers in the Mekong Delta, Vietnam. Based on protection motivation theory, farmers’ assessments of private adaptive measures were measured by perceived self-efficacy, perceived adaptation efficacy and perceived adaptation cost. Multiple regressions were used to understand significant factors affecting those assessments. Some demographic and socio-economic factors, belief in climate change, information and objective resources were found to influence farmers’ adaptation assessments. It is shown that the sources and quality of information are particularly important. The improvement of both the accessibility and usefulness of local services (e.g. irrigation, agricultural extension, credit and health care) is deemed a necessity for successful adaptation strategies in the Mekong Delta. The paper also shows the application of PMT in measuring farmers’ appraisals of private adaptive measures to climate change, thereby opening this area for further research.  相似文献   

山西省早白垩纪碳酸岩元素同位素和锆石U-Pb定年研究     

刘燊  冯彩霞  胡瑞忠  赖绍聪  Ian M Coulson  冯光英  杨毓红 《岩石学报》2014,30(2):350-360

碳酸岩广泛出露在华北克拉通的山西省。此文中,针对研究区的碳酸岩墙,我们给出新的地球化学、Sr-Nd同位素和锆石U-Pb年龄。LA-ICP-MS锆石定年结果显示,该岩墙的侵位年龄为132.9Ma,全岩K-Ar年龄为131.3~132.6 Ma。碳酸岩墙具有非常一致的主量元素组成,富集轻稀土元素和大离子亲石元素(Ba、U、Pb、Sr),以及亏损K和高场强元素(Ta、P和Ti)。另外,该岩墙具有相对一致的(87Sr/86Sr)i(0.7079~0.7083)和负的εNd(t)(-16.7~-15.2)。以上地球化学特征表明,该岩墙为大陆地壳和此大陆岩石圈地幔混合时期,受明显地壳混染的下岩石圈地幔的部分熔融作用。  相似文献   

The economics of inaction on climate change: a sensitivity analysis     

Frank Ackerman  Ian J. Finlayson 《Climate Policy》2013,13(5):509-526

Abstract

Economic models of climate change often take the problem seriously, but paradoxically conclude that the optimal policy is to do almost nothing about it. We explore this paradox as seen in the widely used DICE model. Three aspects of that model, involving the discount rate, the assumed benefits of moderate warming, and the treatment of the latest climate science, are sufficient to explain the timidity of the model's optimal policy recommendation. With modifications to those three points, DICE shows that the optimal policy is a much higher and rapidly rising marginal carbon price; and that higher carbon price has a greater effect on physical measures of climate impacts. Our modifications exhibit nonlinear interactions; at least at low discount rates, there is synergy between individual changes to the model. At low discount rates, the inherent uncertainty about future damages looms larger in the analysis, rendering long-run economic modelling less useful. Our analysis highlights the sensitivity of the model to three debatable assumptions; it does not, and could not, lead to a more reliably ‘optimal’ cost of carbon. Cost-effectiveness analysis, focusing on the generally shorter-term cost side of the problem, reduces the economic paradoxes of the long run, and may make a greater contribution than economic optimization modelling.  相似文献   

Correction to: Evaluation of a multi-model approach to estimate leaf wetness duration: an essential input for disease alert systems     

Gama  Andre B.  Perondi  Daniel  Dewdney  Megan M.  Fraisse  Clyde W.  Small  Ian M.  Peres  Natalia A. 《Theoretical and Applied Climatology》2022,149(1-2):101-101

Theoretical and Applied Climatology -  相似文献   

Experimental simulation of oxygen isotopic exchange in olivine and implication for the formation of metamorphosed carbonaceous chondrites     

Marina A. Ivanova  Cyril A. Lorenz  Ian A. Franchi  Andrei Y. Bychkov  Jeffrey E. Post 《Meteoritics & planetary science》2013,48(10):2059-2070

We have conducted hydration–dehydration experiments on terrestrial olivine to investigate the behavior of oxygen isotopic fractionation to test the hypothesis that multiple cycles of aqueous and thermal processing on a parent asteroid comprise a genetic relationship between CM2s and metamorphosed carbonaceous chondrites (MCCs). Two experiments were undertaken. In the first experiment, serpentine was obtained by hydrating terrestrial olivine (Fo_90.9) in the laboratory. During this experiment, olivine was reacted with isotopically heavy water (δ¹⁸O 21.5‰) at T = 300 °C,  = 300 bar, for 100 days. The oxygen isotopic composition of the experimental serpentine was enriched in ¹⁸O (by 10 ‰ in δ¹⁸O) due to exchange of oxygen isotopes between olivine and the ¹⁸O‐rich water. Dehydrated serpentine was then produced during laboratory heating experiment in vacuum, at T = 930 °C, for 1 h. The oxygen isotopic composition of the dehydrated serpentine was enriched in ¹⁸O by a further 7 ‰. The net result of the hydration–dehydration process was an enrichment of ¹⁸O in the final material by approximately 17‰. The new experimental results suggest that the oxygen isotopic compositions of MCCs of the Belgica‐like group, including Dhofar 225 and Dhofar 725, could be derived from those of typical CM2 chondrites via several cycles of hydration–dehydration caused by aqueous alteration and subsequent thermal metamorphism within their parent asteroids.  相似文献   

Solar Rotational Periodicities and the Semiannual Variation in the Solar Wind, Radiation Belt, and Aurora     

Barbara A. Emery  Ian G. Richardson  David S. Evans  Frederick J. Rich  Gordon R. Wilson 《Solar physics》2011,274(1-2):399-425

The behavior of a number of solar wind, radiation belt, auroral and geomagnetic parameters is examined during the recent extended solar minimum and previous solar cycles, covering the period from January 1972 to July 2010. This period includes most of the solar minimum between Cycles 23 and 24, which was more extended than recent solar minima, with historically low values of most of these parameters in 2009. Solar rotational periodicities from 5 to 27 days were found from daily averages over 81 days for the parameters. There were very strong 9-day periodicities in many variables in 2005?–?2008, triggered by recurring corotating high-speed streams (HSS). All rotational amplitudes were relatively large in the descending and early minimum phases of the solar cycle, when HSS are the predominant solar wind structures. There were minima in the amplitudes of all solar rotational periodicities near the end of each solar minimum, as well as at the start of the reversal of the solar magnetic field polarity at solar maximum (～?1980, ～?1990, and ～?2001) when the occurrence frequency of HSS is relatively low. Semiannual equinoctial periodicities, which were relatively strong in the 1995?–?1997 solar minimum, were found to be primarily the result of the changing amplitudes of the 13.5- and 27-day periodicities, where 13.5-day amplitudes were better correlated with heliospheric daily observations and 27-day amplitudes correlated better with Earth-based daily observations. The equinoctial rotational amplitudes of the Earth-based parameters were probably enhanced by a combination of the Russell-McPherron effect and a reduction in the solar wind-magnetosphere coupling efficiency during solstices. The rotational amplitudes were cross-correlated with each other, where the 27-day amplitudes showed some of the weakest cross-correlations. The rotational amplitudes of the >?2 MeV radiation belt electron number fluxes were progressively weaker from 27- to 5-day periods, showing that processes in the magnetosphere act as a low-pass filter between the solar wind and the radiation belt. The A _p/K _p magnetic currents observed at subauroral latitudes are sensitive to proton auroral precipitation, especially for 9-day and shorter periods, while the A _p/K _p currents are governed by electron auroral precipitation for 13.5- and 27-day periodicities.  相似文献   

Preface     

Steven J. Schwartz  Petr Hellinger  Stuart Bale  Christopher Owen  Rumi Nakamura  Andris Vaivads  Luca Sorriso-Valvo  William Liu  Robert Wimmer-Schweingruber  Masaki Fujimoto  Ian Mann 《Planetary and Space Science》2011,59(7):447-448

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A NanoSIMS and Raman spectroscopic comparison of interplanetary dust particles from comet Grigg‐Skjellerup and non‐Grigg Skjellerup collections     

Jemma DAVIDSON  Henner BUSEMANN  Ian A. FRANCHI 《Meteoritics & planetary science》2012,47(11):1748-1771

Abstract– Interplanetary dust particles (IDPs) are the most primitive extraterrestrial material available for laboratory studies and may, being likely of cometary origin, sample or represent the unaltered starting material of the solar system. Here we compare IDPs from a “targeted” collection, acquired when the Earth passed through the dust stream of comet 26P/Grigg‐Skjellerup (GSC), with IDPs from nontargeted collections (i.e., of nonspecific origin). We examine both sets to further our understanding of abundances and character of their isotopically anomalous phases to constrain the nature of their parent bodies. We identified ten presolar silicates, two oxides, one SiC, and three isotopically anomalous C‐rich grains. One of seven non‐GSC IDPs contains a wealth of unaltered nebula material, including two presolar silicates, one oxide, and one SiC, as well as numerous δD and δ¹⁵N hotspots, demonstrating its very pristine character and suggesting a cometary origin. One of these presolar silicates is the most ¹⁷O‐rich discovered in an IDP and has been identified as a possible GEMS (glass with embedded metal and sulfides). Organic matter in an anhydrous GSC IDP is extremely disordered and, based on Raman spectral analyses, appears to be the most primitive IDP analyzed in this study, albeit only one presolar silicate was identified. No defining difference was seen between the GSC and non‐GSC IDPs studied here. However, the GSC collectors are expected to contain IDPs of nonspecific origin. One measure alone, such as presolar grain abundances, isotopic anomalies, or Raman spectroscopy cannot distinguish targeted cometary from unspecified IDPs, and therefore combined studies are required. Whilst targeted IDP populations as a whole may not show distinguishable parameters from unspecified populations (due to statistics, heterogeneity, sampling bias, mixing from other cometary sources), particular IDPs in a targeted collection may well indicate special properties and a fresh origin from a known source.  相似文献   

The first extrasolar planet detected via gravitational microlensing     

Ian A. Bond 《New Astronomy Reviews》2012,56(1):25-32

In gravitational microlensing, distant planetary systems may be discovered by utilizing them as naturally occuring lenses. Efforts to find planets by this technique began in the 1990s. The first definitive detection of an extrasolar planet by microlensing was made in 2003 in the event OGLE 2003-BLG-235/MOA 2003-BLG-53, where the observed light curve was best reproduced using a binary microlensing model with a mass ratio of 0.004. Further observations with the HST revealed that the lens system comprises a 2.6 Jupiter mass planet in a 4.3 A.U. wide orbit around a 0.6 Solar mass K dwarf at a distance of 5.8 Kpc. Subsequently, the number of planets detected by microlensing is increasing.  相似文献   

How Reliable are Citizen‐Derived Scientific Data? Assessing the Quality of Contrail Observations Made by the General Public     

Amy Fowler  J. Duncan Whyatt  Gemma Davies  Rebecca Ellis 《Transactions in GIS》2013,17(4):488-506

Citizen science projects encourage the general public to participate in scientific research. Participants can contribute large volumes of data over broad spatial and temporal frames; however, the challenge is to generate data of sufficient quality to be useable in scientific research. Most observations made by citizen‐scientists can be independently verified by “experts”. However, verification is more problematic when the phenomena being recorded are short‐lived. This article uses a GIS methodology to verify the quality of contrail observations made by the general public as part of the OPAL Climate Survey. We verify observations using datasets derived from a variety of different sources (experts, models and amateur enthusiasts) with different spatial and temporal properties which reflect the complex 3D nature of the atmosphere. Our results suggest that ～70% of citizen observations are plausible, based on favorable atmospheric conditions and the presence or absence of aircraft; a finding which is in keeping with other, more conventional citizen science projects. However, questions remain as to why the quality of the citizen‐based observations was so high. Given the lack of supporting data on observers, it is impossible to determine whether the dataset was generated by the activities of many participants or a small but dedicated number of individual observers.  相似文献