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171.
The objective of this paper is to better understand the various individual and household factors that influence resilience, that is, people⬢s ability to respond adequately to shocks and stressors. One of our hypotheses is that resilience does not simply reflect the expected effects of quantifiable factors such as level of assets, or even less quantifiable social processes such as people⬢s experience, but is also determined by more subjective dimensions related to people⬢s perceptions of their ability to cope, adapt or transform in the face of adverse events. Data collected over two years in Fiji, Ghana, Sri Lanka and Vietnam confirms the importance of wealth in the recovery process of households affected by shocks and stressors. However our results challenge the idea that within communities, assets are a systematic differentiator in people⬢s response to adverse events. The findings regarding social capital are mixed and call for more research: social capital had a strong positive influence on resilience at the community level, yet our analysis failed to demonstrate any tangible positive correlation at the household level. Finally, the data confirm that, like vulnerability, resilience is at least in part socially constructed, endogenous to individual and groups, and hence contingent on knowledge, attitudes to risk, culture and subjectivity.  相似文献   
172.
On days that are quiet with respect to solar-terrestrial activity phenomena, the geomagnetic field has variations, tens of gamma in size, with major spectral components at about 24, 12, 8, and 6 hr in period. These quiet daily field variations are primarily due to the dynamo currents flowing in theE region of the earth's ionosphere, are driven by the global thermotidal wind systems, and are dependent upon the local tensor conductivity and main geomagnetic field vector. The highlights of the behavior and interpretation of these quiet field changes, from their discovery in 1634 until the present, are discussed as an introduction to the special journal issue on Quiet Daily Geomagnetic Fields.  相似文献   
173.
The distribution of rainfall over small-scale topography of uniformroughness was studied both numerically and from field observations. Field data haveshown that small-scale topographic inhomogeneities (hills and valleys of afew tens of metres in height) substantially influence the rainfalldistribution over the inhomogeneity itself and also some distance downwind from it.According to comprehensive rainfall measurements carried out in a smallwatershed, windward slopes received less conventionally-measured rain than lee-sides.Moreover, on the windward slope rainfall decreased uphill, to apronounced minimum near the crest. In addition, directional raingages,situated at the bottom of both slopes revealed a pattern suggesting a reversedsurface flow on the lower slopes. This pattern persisted through a variety ofbackground conditions.To explain the observed data, a numerical simulation of both the windfieldand of drop trajectories was carried out. The windfield was generated insimulations using the Colorado State University RAMS model with a very highresolution (5 m in the horizontal). Drop trajectories were calculated usingan equation for the motion of drops in a flow field that incorporates currentexperimental results.A strong effect of small-scale topography on drop trajectories wasfound. The simulation results are encouraging and help to explain manycharacteristic features of precipitation distributions observed in fieldexperiments.  相似文献   
174.
A landing obligation was formally implemented in the European Union (EU) for the first time, as part of the recent reform of the EU Common Fisheries Policy (CFP). Given the reasonable success of the landing obligation in some countries such as the Faroe Islands, Iceland and Norway, this policy is seen as a viable approach to tackle the long-recognized discarding problem in EU waters. However, there has been some debate on whether there is sufficient evidence to support the feasibility of such a measure in the EU-CFP. The EU landing obligation will implicitly include all small-scale fisheries (SSF) provided the species captured are subject to catch limits or minimum sizes (in the case of the Mediterranean). SSF were included irrespective of the fact that the discarding problem in the EU has been historically associated with medium- to large-scale fleets (in particular largely mixed species trawl fisheries). Additionally, past experiences with a discard ban policy are still limited to specific countries and/or specific fisheries. This paper examined the appropriateness and feasibility of the recently implemented EU landing obligation in SSF. The effects in the long-term are unpredictable, but available evidence suggests that in the short to medium-term a landing obligation is likely to bring more negative social, economic and ecological impacts than benefits.  相似文献   
175.
Scholarship on gender in fisheries is not new. However, while there are many studies on the context and politics of gender and fisheries, understanding how power influences gender equality remains understudied, especially in the Western Indian Ocean. Based on evidence gathered from an interdisciplinary set of literature, including sectoral policies, this article provides nuanced insight at rethinking - how gendered-power dynamics constrain and enable choices and opportunities for addressing gender inequality in small-scale fisheries. Compelling evidence shows that a gendered-power dynamic is crucial for renegotiating gender equality with social norms and politics, including challenging simplistic views on poverty, vulnerability, and subordination of women. The article presents a latent chance for greater reflexivity among development practitioners, researchers, and policymakers on the politics of and transformation towards gender equality in small-scale fisheries.  相似文献   
176.
Global visions of environmental change consider gender equality to be a foundation of sustainable social-ecological systems. Similarly, social-ecological systems frameworks position gender equality as both a precursor to, and a product of, system sustainability. Yet, the degree to which gender equality is being advanced through social-ecological systems change is uncertain. We use the case of small-scale fisheries in the Pacific Islands region to explore the proposition that different social-ecological narratives: (1) ecological, (2) social-ecological, and (3) social, shape the gender equality priorities, intentions and impacts of implementing organizations. We conducted interviews with regional and national fisheries experts (n = 71) and analyzed gender commitments made within policies (n = 29) that influence small-scale fisheries. To explore these data, we developed a ‘Tinker-Tailor-Transform’ gender assessment typology. We find that implementing organizations aligned with the social-ecological and social narratives considered social (i.e., human-centric) goals to be equally or more important than ecological (i.e., eco-centric) goals. Yet in action, gender equality was pursued instrumentally to achieve ecological goals and/or shallow project performance targets. These results highlight that although commitments to gender equality were common, when operationalized commitments become diluted and reoriented. Across all three narratives, organizations mostly ‘Tinkered’ with gender equality in impact, for example, including more women in spaces that otherwise tended to be dominated by men. Impacts predominately focused on the individual (i.e., changing women) rather than driving communal-to-societal level change. We discuss three interrelated opportunities for organizations in applying the ‘Tinker-Tailor-Transform’ assessment typology, including its utility to assist organizations to orient toward intrinsic goals; challenge or reconfigure system attributes that perpetuate gender inequalities; and consciously interrogate discursive positions and beliefs to unsettle habituated policies, initiatives and theories of change.  相似文献   
177.
178.
I have examined precisely the differential travel times and waveforms of SmKS seismic phases propagating under the southern Indian Ocean obtained from African broadband seismic arrays. The SmKS phases analyzed in this study travel in the mantle with weak heterogeneity confirmed by a global tomographic study for the distance range of 115-135°. The SmKS differential times were obtained from a vespagram (a stack intensity on a time-slowness diagram), and comparison with the vespagram created from synthetic waveforms with PREM gives the travel-time residual for each event-array pair. Although the residuals of S3KS-S2KS times exhibit apparently a systematic dependence on epicentral distance, this is likely due to small-scale heterogeneity beneath the Oceania where is covered by the SmKS ray entering points at the CMB. Waveform modeling was applied to a record section with a small travel-time residual that suggests a small effect from the mantle heterogeneity on the data set, I found that a low-velocity zone in the outermost 50 km in the core rather than PREM can explain an additional arrival detected just after the S3KS phase. This result is still inconclusive because of the small number of data and non-uniqueness of the model and ambiguity due to mantle structure. However, accumulation of the precise measurement described in this study may help the reduction of uncertainty and trade-offs.  相似文献   
179.
Huancayo is the only equatorial electrojet station where the daytime increase of horizontal geomagnetic field (H) is associated with a simultaneous increase of eastward geomagnetic field (Y). It is shown that during the counter electrojet period when H is negative, Y also becomes negative. Thus, the diurnal variation of Y at equatorial latitudes is suggested to be a constituent part of the equatorial electrojet current system. Solar flares are known to increase the H field at an equatorial station during normal electrojet conditions (nej). At Huancayo, situated north of the magnetic equator, the solar flare effect, during nej, consists of positive impulses in H and Y and negative impulse in Z field. During counter electrojet periods (cej), a solar flare produces a negative impulse in H and Y and a positive impulse in Z at Huancayo. It is concluded that both the zonal and meridional components of the equatorial electrojet in American longitudes, as in Indian longitudes, flows in the same, E region of the ionosphere.  相似文献   
180.
雷天  李忠海  刘勉 《地球物理学报》1954,63(10):3727-3739
地质与地球物理观测数据表明青藏高原、安第斯山、以及帕米尔等典型造山高原之下均有明显的岩石圈地幔小尺度/分段式减薄现象.这些小尺度岩石圈减薄难以用经典的拆沉或对流减薄理论来解释,一方面,拆沉预示大尺度岩石圈地幔的剥离过程,而对流减薄则在黏度相对低的地幔岩石圈中发生,其主要以小尺度的局部增厚触发并仅减薄地幔岩石圈的底部区域.另一方面,拆沉或对流减薄模型都预测造山带尺度的地幔岩石圈拆离,都假设造山带岩石圈横向均一,然而实际的造山带岩石圈往往由多个不同的地块构成,块体之间岩性、物性、流变结构可能大有差别,即横向不均一性.这些造山带岩石圈地幔的横向不均一性,能否有效解释观测到的局部小尺度减薄现象?为此,我们构建了一系列高精度动力学数值模型,系统模拟了碰撞造山过程中岩石圈地幔的形变和不稳定性.结果表明,在塑性屈服强度很低的情况下,横向不均一的造山带岩石圈有发生分段式/小尺度减薄的可能性;其主要机理是由位错蠕变与强塑性作用所导致的应变集中使得地块间及壳幔间耦合弱化,从而使得较弱地块的岩石圈地幔在增厚时由于重力不稳定性而产生局部剥离,进而诱发小尺度软流圈上涌.模拟结果可以良好地解释发生在青藏高原东北缘、安第斯中部高原、以及帕米尔高原之下岩石圈的局部小尺度/分段式减薄现象.  相似文献   
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