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Reducing Emissions from Deforestation and Forest Degradation projects currently cover an area approximately twice the size of Germany and challenge traditional concepts of centralization and decentralization in studies of environmental governance. Emerging from the interactions of a complex network of actors, Reducing Emissions from Deforestation and Forest Degradation demonstrates that transnational governance networks of organizations can become spatially centralized. Using a historical analysis of the development of Reducing Emissions from Deforestation and Forest Degradation, we argue that the evolution of Reducing Emissions from Deforestation and Forest Degradation policy has been directed primarily from donor countries, especially in North America and Europe. Adopting a social network analysis approach, we present findings from a new dataset of collaboration on 276 Reducing Emissions from Deforestation and Degradation, avoided deforestation, and sustainable forest management projects that began some on-the-ground operations between 1989 and June 2012, finding that organizations in donor countries have from the beginning been the central actors in the Reducing Emissions from Deforestation and Forest Degradation network. We conclude that Reducing Emissions from Deforestation and Forest Degradation exhibits spatial centralization within transnational governance architectures despite institutional fragmentation, raising important normative questions about participation in transnational forest governance. 相似文献
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R. M. Palin M. P. Searle D. J. Waters R. R. Parrish N. M. W. Roberts M. S. A. Horstwood M.‐W. Yeh S.‐L. Chung T. T. Anh 《Journal of Metamorphic Geology》2013,31(4):359-387
The Red River shear zone (RRSZ) is a major left‐lateral strike‐slip shear zone, containing a ductilely deformed metamorphic core bounded by brittle strike‐slip and normal faults, which stretches for >1000 km from Tibet through Yunnan and North Vietnam to the South China Sea. The RRSZ exposes four high‐grade metamorphic core complexes along its length. Various lithologies from the southernmost core complex, the Day Nui Con Voi (DNCV), North Vietnam, provide new constraints on the tectonic and metamorphic evolution of this region prior to and following the initial India–Asia collision. Analysis of a weakly deformed anatectic paragneiss using P–T pseudosections constructed in the MnO–Na2O–CaO–K2O–FeO–MgO–Al2O3–SiO2–H2O–TiO2–O (MnNCKFMASHTO) system provides prograde, peak and retrograde metamorphic conditions, and in situ U–Th–Pb geochronology of metamorphic monazite yields texturally controlled age constraints. Tertiary metamorphism and deformation, overprinting earlier Triassic metamorphism associated with the Indosinian orogeny and possible Cretaceous metamorphism, are characterized by peak metamorphic conditions of ~805 °C and ~8.5 kbar between c. 38 and 34 Ma. Exhumation occurred along a steep retrograde P–T path with final melt crystallizing at the solidus at ≥~5.5 kbar at ~790 °C. Further exhumation at ~640–700 °C and ~4–5 kbar at c. 31 Ma occurred at subsolidus conditions. U–Pb geochronological analysis of monazite from a strongly deformed pre‐kinematic granite dyke from the flank of the DNCV provides further evidence for exhumation at this time. Magmatic grains suggest initial emplacement at 66.0 ± 1.0 Ma prior to the India–Asia collision, whereas grains with metamorphic characteristics indicate later growth at 30.6 ± 0.4 Ma. Monazite grains from a cross‐cutting post‐kinematic dyke within the core of the DNCV antiform provide a minimum age constraint of 25.2 ± 1.4 Ma for the termination of fabric development. A separate and significant episode of monazite growth at c. 83–69 Ma is suggested to be the result of fluid‐assisted recrystallization following the emplacement of magmatic units. 相似文献
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Euripides Papamichos 《国际地质力学数值与分析法杂志》2010,34(6):581-603
Borehole failure under anisotropic stresses in a sandstone is analyze numerically for various borehole sizes using a nonlinear elastic–plastic constitutive model for a Cosserat continuum. Borehole failure is identified as macroscopic failure of the borehole through the development of shear bands and breakouts. The results compare well both qualitatively and quantitatively with experimental results from polyaxial tests on Red Wildmoor sandstone. They show that the hole size effect of the borehole failure strength is independent of the far‐field stress anisotropy and follows a ? power law of the hole size. A similar scale effect equation with a ? power law is proposed for the scale effect of the maximum plastic shear strain at failure. This equation can be useful for better predicting hole‐size‐dependent failure with standard codes based on classical continua. The effect of stress anisotropy on the borehole failure stress is found to be independent of the hole size. The failure stress decreases linearly to 40% as the stress anisotropy increases. However, the maximum plastic shear strain at failure is stress anisotropy independent and therefore the critical plastic shear strain for failure is only hole‐size dependent. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Chenglong Ma Xiaodong Chen Liming Jiang Heping Sun Jianqiao Xu Jinglong Dong Dewei Li 《地球科学进展》2019,34(2):164-174
Based on the principle of InSAR (Interferometirc Synthetic Aperture Radar) characterized by large-scale, continuity, permanency and dynamic, we took vertical displacement of solid Earth tide as an example to simulate the large-scale deformation observed by lunar based InSAR for the first time in the study and the observation ability was analyzed. Solid Earth tide has a feature of a large-space distribution range and the lunar based InSAR exhibits a feature of an ultra-wide swath imaging. According to these features, a simplified observation geometry model was established and a mid-low latitudes area with 50 degrees span in both longitude and latitude was selected as the simulation area. Then the revisit time intervals of the lunar based SAR for the selected area and the tidal vertical displacements at the points scanned by the radar were calculated. The time differentials were further computed to get the relative vertical deformation of the solid Earth tide. The simulation results show that the revisit period of the lunar based radar is about 24.8 hours and the maximum vertical displacement in 30 days is up to 30 cm. Since the designed accuracy of the lunar based InSAR reaches several centimeters, the observing of the vertical displacement of the solid Earth tide by using the lunar based InSAR is feasible in theory as the maximum magnitude of the vertical displacement is 1 order of magnitude larger than the designed accuracy. Theoretically ,solid Earth tide is observable by using lunar based InSAR in a sizable area.We can also use the observation data to study the temporal and spatial variation characteristics when observation time lasts two revisit periods or more. On the other hand,the result of the study also provides references for the parameter designing of other observations using the lunar based InSAR, especially for observing large-scale geodynamic phenomena. 相似文献
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?????????????GRACE Follow??On?????E.MOTION??Earth System Mass Transport Mission????????????????????о???????????????????Post??GRACE????????????????????????ο???????????????????????Post??GRACE??????????????????о??????????????????????????????????????????????????????????????????????????????????????о????????????????????????????? 相似文献
80.
Chih-Shin Chen 《Marine Policy》2012,36(3):623-629
Precious corals have been commercially exploited because of their legendary and cultural importance for many centuries in the Mediterranean and for almost one century in the Northwest Pacific. Although the precious coral fishery in Taiwan dates back to the 1920s, relevant studies on biology and ecology of resources are relatively scarce. The management of the precious coral fishery in Taiwan was officially instituted in January 2009, when data on the catch and effort of the fishery were recorded. In this study, the catch-effort data of the fishery were examined to explore the temporal and spatial patterns in composition and abundance of Corallium and Paracorallium spp. around Taiwan. A total landing of 3233.0 and 2906.8 kg precious corals were recorded for 2009 and 2010, respectively. Less than 5% of those amounts were from live colonies. A high proportion of fossilized colonies in the catch reflect the non-selective nature of the fishing gear; however, the factors that cause colonies to collapse are not exclusive to the impact of the fishery. Momo coral was dominant in the production for both years, followed by Miss coral. The total production of precious corals correlated positively with fishing efforts, while a weak relationship was found between the production of live colonies and fishing efforts. The fishing efforts mainly aggregated in designated fishing ground A (DFG-A) for both years, while the production of live colonies mainly occurred in DFG-E. The monthly occurrence rate of live colonies decreased over the past 2 years. Although fluctuating significantly, the CPUE of dominant species exhibited an apparent decreasing pattern. High aggregation of the fishing efforts in specific regions and low numbers of live colonies in the production should be carefully taken into account when amending management regulations in the future. The establishment of marine protected areas, in addition to the strict controls that already apply, should be considered to not only sustain the population structure of the sessile animals but also their function in the marine ecosystem. 相似文献