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131.
This paper explores the relationship between disaster risk reduction and long-term adaptive capacity building in two climate vulnerable areas—the Cayman Islands in the Caribbean and Ceará, in NE Brazil. Drawing on past applications of the disaster risk reduction framework, we identify four critical factors that have led to reductions in risk: flexible, learning-based, responsive governance; committed, reform-minded and politically active actors; disaster risk reduction integrated into other social and economic policy processes; and a long-term commitment to managing risk. We find that while the presence of these factors has reduced overall risk in both regions, in Ceará, disaster response as it is currently practiced, has fallen short of addressing the fundamental causes of vulnerability that leave those prone to hazards able to cope in the short term, yet enmeshed in poverty and at risk from the longer-term changes associated with climate change. Although calls for integration of disaster risk management with poverty eradication are not new, there has been insufficient attention paid in the literature on how to foster such integration. Based on the two case studies, we argue that the adoption of good governance mechanisms (such as stakeholder participation, access to knowledge, accountability and transparency) in disaster risk reduction policy may create the policy environment that is conducive to the kind of structural reform needed to build long-term adaptive capacity to climate-driven impacts. We conclude that without a synergistic two-tiered approach that includes both disaster risk reduction and structural reform, disaster risk reduction, in the face of climate changes, will prove to be an expensive and ineffective palliative treatment of changing risks.  相似文献   
132.
Sr/Ca, B/Ca, Mg/Ca and δ11B were determined at high spatial resolution across ∼1 year of a modern Hawaiian Porites lobata coral by secondary ion mass spectrometry (SIMS). We observe significant variations in B/Ca, Mg/Ca, Sr/Ca and δ11B over short skeletal distances (nominally equivalent to periods of <20 days). This heterogeneity probably reflects variations in the composition of the extracellular calcifying fluid (ECF) from which the skeleton precipitates. Calcification site pH (total scale) was estimated from skeletal δ11B and ranged from 8.3 to 8.8 (± ∼0.1) with a mean of ∼8.6. Sr/Ca and B/Ca heterogeneity is not simply correlated with calcification site pH, as might be expected if Ca-ATPase activity increases the pH and decreases the Sr/Ca and B(OH)4/CO32− ratios of the ECF. We produced a simple model of the ECF composition and the skeleton deposited from it, over a range of calcium transport and carbonate scenarios, which can account for these observed geochemical variations. The relationship between the pH and Sr/Ca of the ECF is dependent on the concentration of DIC at the calcification site. At higher DIC concentrations the ECF has a high capacity to buffer the [H+] changes induced by Ca-ATPase pumping. Conversely, at low DIC concentrations, this buffering capacity is reduced and ECF pH changes more rapidly in response to Ca-ATPase pumping. The absence of a simple correlation between ECF pH and skeletal Sr/Ca implies that calcification occurred under a range of DIC concentrations, reflecting variations in the respiration and photosynthesis of the coral and symbiotic zooxanthellate in the overlying coral tissues. Our observations have important implications for the use of coral skeletons as indicators of palaeo-ocean pH.  相似文献   
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The extraction of P-T histories from metamorphic rocks provides a valuable dataset for the elucidation of the tectonic mechanisms for orogeny. While continued re-equilibration frequently obliterates early information, garnet zonation and inclusion assemblages can often surmount this problem. The task is more difficult in high variance assemblages or if inclusions are not preserved, but one approach is to use pseudosections that are specific to the bulk composition of a given rock. In the latter case, the compositions and abundances of all the minerals are fixed at a given P-T point such that, if the effective bulk composition is known, the garnet composition alone can be used to reconstruct the history. Here, we explore this approach using examples from the Zanskar Himalaya, NW India. Pseudosections have been calculated for four pelitic to semipelitic rocks from the Zanskar Himalaya and have been contoured for garnet composition. The calculations adequately model the mineral assemblages in the rocks and predict the presence of chlorite in the early assemblage where chlorite is found as inclusions within garnet. Moreover, the pseudosections successfully model the garnet core compositions, with all three independent compositional contours overlapping at a single pressure and temperature. This occurs at ∼550 °C and at pressures varying from 3–7 kbar for the four rocks studied. We have been less successful, however, at modelling garnet compositions beyond the cores because fractionation of the effective bulk composition is caused by garnet growth itself. However, in this case, a combination of the␣pseudosection and conventional thermobarometry using␣Fe-Ti inclusions and matrix phases allows us to reconstruct␣the entire P-T history. The resulting P-T paths record burial of 3–5 kbar without significant temperature increase followed by isobaric heating of 50–100 °C. This evolution is consistent with Himalayan collision in the early Tertiary but a combination of the P-T data presented here and published geochronological data suggests renewed thrusting south of the suture zone in the Oligocene. In addition, the data demonstrate that no extra heat source is required to cause melting of the Himalayan crust in the Miocene. While melting could have occurred both by dehydration during decompression or in the presence of a fluid, the lack of garnet resorption does suggest decompression was rapid and followed quickly by cooling. This scenario favours melting by decompression. Received: 17 July 1997 / Accepted: 6 April 1998  相似文献   
135.
In the shallow water of Orbetello lagoon, macroalgae harvesting boats produce sediment disturbance. To evaluate the effect of this, during 2001-2002, a trial study was carried out in the lagoon in order to: verify seasonal and diurnal trends in nutrients and estimate the quantity of resuspended organic sediment. An unbalanced and balanced ANOVA (one and two way) analysis was applied. The disturbance did not produce strong and lasting eutrophication effects. In the seasonal survey, dissolved inorganic nitrogen (DIN) and soluble reactive phosphorus (SRP) showed significant decreases in disturbed areas at the end of the trial, while the control area showed a constant, significant increase. Dissolved organic nitrogen (DON) and phosphorus (DOP) significantly increased everywhere. In disturbed areas, sediment redox (Eh((NHE))) increased and porosity values decreased, contrary to the control area. Total organic carbon (TOC) remained unchanged in disturbed areas, but increased in the control area, where the C:P ration increased. The fall-out of sedimentary material resuspended by boat action for as far as 50 m from the boat route, was 189 g(dw)m(-2) made up mainly of organic matter. This disturbance could be the cause of change in vegetation in the lagoon.  相似文献   
136.
The tidally-induced couple acting on the Moon, due to friction between the oceans and their beds, is calculated as a function of the Earth-Moon separation. The function is found to be proportional to 1+d/R 3 , and not the previously used 1/R 6. By use of this new function it is found that the present rate of lunar recession gives an acceptable history for the system if it is assumed the Moon was initially in a close geo-stationary orbit 4 billion years ago, when perturbed by the condensation of the Earth's core.  相似文献   
137.
D.L. Carr  Emma S. Norman 《Geoforum》2008,39(1):358-371
In the face of mounting environmental degradation and persistent poverty over the previous decade, Johannesburg’s World Summit on Sustainable Development (WSSD) of August and September 2002 inherited a number of unmet accords from the 1992 Rio de Janeiro Earth Summit. Consequently, the United Nations Stakeholder Forum Implementation Conference (IC) was convened to integrate civil society stakeholders into global deliberations on sustainable development and to marshal their forces in the implementation of WSSD accords. Given the importance of the IC as the first civil society forum at a major global summit on environment and poverty, intriguing questions emerge as to its effectiveness in achieving civil society objectives. As a first attempt in exploring this topic, we examine three fundamental aspects of the IC. Specifically, we examine the relative “civility” of the IC forum in terms of (a) fidelity of representation of the community of global environment and development stakeholders; (b) autonomy of the IC agenda from state and institutional interests; and (c) interpretations of space and place as reflected in deliberative processes and outcomes. The paper begins with a review of the civil society literature with a particular emphasis on civil society representation in UN meetings since Rio. The paper concludes with a discussion of IC participation at the Johannesburg summit, and considers implications for future civil society participation in global decision-making forums.  相似文献   
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139.
222Rn was used to assess river–groundwater interactions within Castel di Sangro alluvial aquifer (Italy). The effectiveness of results obtained through this indicator was verified by also analyzing δ18O, major ions and temperature in both surface and groundwater, and carrying out piezometric head monitoring and discharge measurements. Hydrogeological investigations suggested that the river infiltrates into the aquifer in the south-eastern aquifer portion, while groundwater discharges into the river in the north-eastern portion. The latter phenomenon is supported by 222Rn data. Nevertheless, flow-through conditions cause the modelled discharge along this river reach, estimated by 222Rn data in a degassing-corrected two-component mixing model, to be greater than the measured discharge. Concerning river infiltration into the aquifer, δ18O, major ions and temperature data show that the river contribution is negligible in terms of aquifer recharge. Thus, the observed increase in 222Rn concentration in that portion of the aquifer is due to the enrichment process caused by infiltration of rainwater (222Rn free) which flows from the local divide area. Hence, in the study site, the use of only 222Rn to predict river–groundwater interactions causes some estimation inaccuracies and it must be coupled with other hydrochemical and hydrogeological parameters to gain a thorough understanding of such interactions.  相似文献   
140.
The aim of the research was to analyse the influence of a topsoil of pyroclastic origin on microbial contamination of groundwater in a carbonate aquifer and verify the reliability of thermotolerant coliforms and fecal enterococci as bacterial indicators. The research was carried out through hydrogeological and microbiological monitoring at an experimental field site in Italy during two hydrologic years and through column tests in a laboratory. The taxonomic classification of fecal indicators detected in spring water samples was performed using API20 galleries. Fecal enterococci were also identified by means of 16S rRNA gene sequencing. The topsoil of pyroclastic origin significantly retains both thermotolerant coliforms and fecal enterococci. Results of column tests carried out in soil blocks collected randomly within the test site suggest that Escherichia coli was more retained than Enterococcus faecalis, even though this difference is statistically significant in only two out of six soil samples. Thus, a non-uniform difference in retention is expected at field scale. This suggestion is in agreement with the results of the microbiological monitoring. In fact, fecal enterococci were a more reliable indicator than thermotolerant coliforms for detecting contamination at both seasonal springs of the aquifer system, while no significant differences were observed at the perennial spring.  相似文献   
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