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991.
Acknowledgement
Referees for volume 8 相似文献992.
993.
Despite its legal prohibition since 1998, the nylon monofilament net is still widely used in Senegalese artisanal fisheries. To achieve a complete ban on monofilament use, it is necessary to understand the main arguments for its continued use and what alternatives exist. Using a field experiment among local fishers as well as empirical knowledge and a literature review, this article highlights the challenges to the eradication of nylon monofilament. Our study shows that in a context where decision-makers pay too much attention to social, economic and political stakes, the efficiency of nylon monofilament nets confers a major advantage upon which fishers rely, and this counters any regulatory action against this type of gear. Moreover, numerous studies globally have indicated that communication campaigns that focus on the ghost-fishing power of this type of net seem to be inappropriate. We concluded that the issue of continued use of monofilament should be addressed through an integrated fisheries management programme that reduces overcapacity and fosters sustainable fishing practices. 相似文献
994.
Brieuc Riou Eric Chaumillon Jean-Luc Schneider Thierry Corrège Catherine Chagué 《Sedimentology》2020,67(3):1577-1600
Extensive bathymetric and two-dimensional seismic surveys have been carried out and cores collected in Pago Pago Bay (Tutuila, American Samoa) in order to describe and gain a better understanding of the sediment fill of the bay, which was affected by the 2009 South Pacific Tsunami. Eight sedimentary units were identified over the volcanic bedrock. The basal transgressive unit displays retrograding onlaps towards the shore, whereas the overlying seven aggradational layers alternate between four draping units and three pinching out seaward units. ‘Core to seismic’ correlation reveals that draping units are composed of homogeneous silts, while pinching out units are dominated by very coarse coral fragments showing fresh cuts, mixed with Halimeda plates. The basal unit is attributed to transgressive sedimentation in response to flooding of the bay after the last glacial maximum, followed by the upper aggradational units corresponding to highstand sedimentation. The changeovers in these upper units indicate an alternation between low-energy silt units and high-energy coral debris units interpreted as tsunami-induced deposits. The 14C dating reveals that high-energy sedimentation units can last up to approximately 2000 years while low-energy sedimentation units can last up to approximately 1000 years. This alternation, deposited during the last highstand, may be explained by cycles of tectonic activity and quiescence of the Tonga Trench subduction, which is the main source of tsunamigenic earthquakes impacting the Samoan archipelago. In the uppermost silt unit, only the geochemical signature of the terrestrial input of the 2009 SPT backwash deposits was detected between 7 cm and 9 cm depth. Hence, Pago Pago Bay offers a unique sediment record of Holocene bay-fill under the impact of past tsunamis intermittently during the last 7000 years. 相似文献
995.
The Peloritani region is one of the most seismically active regions in Italy and, consequently, the quantification of attenuation of the medium plays an important role for seismic risk evaluation. Moreover, it is necessary for the prediction of earth ground motion and future seismic source studies. An in depth analysis has been made here to understand the frequency and lapse time dependence of attenuation characteristics of the region by using the coda of local earthquakes. A regionalization is likewise performed in order to investigate the spatial variation of coda Q across the whole region. Finally, our results are jointly interpreted with those obtained from recently published 3D velocity tomographies for further insights. 相似文献
996.
Antônia Tatiana Pinheiro do Nascimento Natália Holanda Maia Cavalcanti Bruno Parente Leitão de Castro 《水文科学杂志》2019,64(1):80-91
In the Brazilian semi-arid region, thousands of small dams have been built over time to enhance water availability, accumulating water and hydraulic energy at high altitudes. Simulations were performed in this study to assess how the arrangement of reservoirs impacts on the power demand for water distribution in the Banabuiú River Basin (19?800 km2), Brazil. The power required to pump water from 1405 reservoirs to all districts with diffuse demands is 6.5 GWh/year, whereas in the scenario with only the 12 larger strategic reservoirs, the power demand reached 45.3 GWh/year. Alone, the largest reservoir in the basin can supply water to all districts. Nonetheless, in that scenario, the power demand would reach 195 GWh/year, which is 30 times the power required in the real reservoir arrangement. Thus, decentralization by small reservoirs not only promotes more democratic access to water, but also increases energy efficiency by storing it at higher altitudes and closer to the diffuse demands. 相似文献
997.
Xing Zhao Ya Zhiyu Wang Zhaowei Sun Bing Fu Hongrui Bénédicte Massamba-Courtois Joanès 《Water Resources》2020,47(1):95-102
Water Resources - The baffled flasks were used to simulate regular wave and breaking wave at different oscillation intensities to study the effects of wave strength, reaction time, and dispersant... 相似文献