Carbonate sedimentation and hydrodynamic pattern on a modern temperate shelf: The strait of Bonifacio (western Mediterranean)     

Giovanni De Falco  Sandro De Muro  Tiziana Batzella  Andrea Cucco 《Estuarine, Coastal and Shelf Science》2011

The sedimentary features of the inner-middle shelf of the strait of Bonifacio (western Mediterranean) were analyzed to evaluate the relationship between the production and transport of biogenic carbonate sediments and the basin morphology and hydrodynamics. A three-dimensional hydrodynamic modeling was performed in order to simulate the influence of waves and currents at seabed level. Superficial sediments were collected at depths ranging from 5 to 80 m and were analyzed for grain size, mineralogical composition and skeletal carbonate composition. Posidonia oceanica seagrass meadows border the coasts in a narrow strip on both sides of the strait down to a depth of 40 m. At greater depths, the seabed is characterized by the presence of plateaus and ridges which are controlled by outcropping bedrock morphology.  相似文献   

Fortress conservation at sea: A commentary on the Chagos marine protected area     

E.M. De Santo  P.J.S. Jones  A.M.M. Miller 《Marine Policy》2011

The world's largest no-take Marine Protected Area in Chagos is examined in light of the Convention on Biological Diversity's provisions on Access and Benefit Sharing, as well as terrestrial experiences with fortress conservation. It is acknowledged that this closure presents a unique opportunity to preserve an ecologically 'pristine' area. However, the means by which the political process unfolded are brought into question. In particular, the fact that the UK proceeded with designating the area whilst the European Court of Human Rights was deliberating the right of native Chagossians to return to the island is questioned. In addition it is argued that the scale of the area poses significant management and enforcement challenges, which are not necessarily taken into consideration in the rush for large, no-take Marine Protected Areas.  相似文献   

Environmental justice implications of Maritime Spatial Planning in the European Union     

Elizabeth M. De Santo 《Marine Policy》2011

This paper examines the implications of environmental justice in the regime for Maritime Spatial Planning (MSP) currently developing in the European Union (EU). An ‘ecosystem-based approach’ to marine management is enshrined in the new Integrated Maritime Policy and Marine Strategy Framework Directive and forms the basis of MSP. This concept is intended to encompass all aspects of an ecosystem, including the human element. Yet the modes of including meaningful public participation in the decision-making process for MSP remain undetermined. At the same time, the Aarhus Convention (on access to information, public participation in decision making and access to justice in environmental matters) empowers non-governmental organisations to hold EU Member States to account. Consequently the issue of transparency will gain increased importance, as will linkages between human and environmental rights. Such public interest-based activism on the part of NGOs has the potential to enforce the developing framework for stakeholder engagement within MSP, but it also has implications worth considering regarding the appropriate role of interest-based organisations in the international political arena.  相似文献   

Bioturbation effects of Corophium volutator: Importance of density and behavioural activity     

A. De Backer  F. Van Coillie  F. Montserrat  P. Provoost  C. Van Colen  M. Vincx  S. Degraer 《Estuarine, Coastal and Shelf Science》2011

Bioturbation is one of the major processes influencing ecosystem functioning. Population parameters such as species density, burrow density and species-specific life modes, determine the impact of bioturbation on the ecosystem. A laboratory experiment was developed, using microcosms mimicking a marine intertidal sediment–water interface which allowed for quantification of different population parameters. The vertical redistribution, bioturbation rate and maximum penetration depth of two sizes (41 and 129 μm) of luminophores were measured in five treatments (control, low density of burrows with and without Corophium (1989 ind./m²), and high density of burrows with and without Corophium (14,921 ind./m²)) after 1, 7 and 14 days. Results indicate that the behavioural activities of Corophium are of the utmost importance in sediment reworking, since they contributed to a five-fold increase in bioturbation rate compared to the passive transport induced by the static structure of the burrows. Furthermore, density is an important parameter because only high densities play a prominent role in particle transport and hence in organic matter processing, while the role of low Corophium densities is limited in sediment reworking. No evidence for differentiation in sediment size fractions was observed. Finally, bioturbation rates in this study were low compared to other studies, and these results suggest an influence of the tidal rhythmicity in the behavioural activity of Corophium on the bioturbation rate.  相似文献   

基于WebGIS的气象服务产品自动加工关键技术     

丰德恩  唐卫  王慕华  惠建忠  郝江波  王澎涛  李雁鹏 《气象与环境科学》2020,43(1):130-136

针对融媒体时代对气象服务产品加工个性化、准实时、智能化新诉求,以SOA架构组件式开发思想为指导,归纳气象服务产品加工业务共性,提出一套集成应用WebGIS、并行计算和大数据技术的气象服务产品自动化加工解决方案。利用组件开发和工作流引擎技术,搭建面向服务体系架构的产品加工模型装备框架,对产品加工组件进行模型编排,实现无须编程情况下的产品加工模型快速构建;利用基于分布式架构的加工服务器集群技术,搭建加工服务器集群环境,对产品加工模型服务进行发布和管理,实现产品加工任务的秒级高并发处理;利用基于消息和定时机制的加工任务调度技术,开发了产品加工任务调度器,通过设置消息主题和定时计划策略,实现加工任务参数智能解析和适配应用,统一协调触发各加工模型服务进行自动化作业。智能化气象服务产品自动加工系统自业务化运行以来,在加工效率、美观性和扩充性等方面表现出很好的应用价值。以温度、降水、风速、相对湿度全国实况格点服务产品加工为例进行实验,加工耗时由797 s缩减至14 s,效率提高50倍以上。  相似文献   

Erratum to: Simulating cold season snowpack: Impacts of snow albedo and multi-layer snow physics     

D. Waliser  J. Kim  Y. Xue  Y. Chao  A. Eldering  R. Fovell  A. Hall  Q. Li  K. N. Liou  J. McWilliams  S. Kapnick  R. Vasic  F. De Sales  Y. Yu 《Climatic change》2013,116(2):425-425

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Seasonal temperature variations and energy demand     

Enrica De Cian  Elisa Lanzi  Roberto Roson 《Climatic change》2013,116(3-4):805-825

This paper presents an empirical study of the relationship between residential energy demand and temperature. Unlike previous studies in this field, the data sample has a global coverage and special emphasis is given to the heterogeneous response of different regions and to the contrasting effects on energy demand for cooling and heating purposes. To account for this we distinguish between different regions, seasons, and energy sources. Short- and long-run temperature demand elasticities are estimated. These features make the model results especially valuable in the analysis of climate change impacts as they provide an empirical basis for the study of the impact of climate change on energy demand. To illustrate the potential of the results as a basis for the study of climate change impacts, the estimates are used in a simple exercise that projects changes in energy demand due to temperatures increase in 2085.  相似文献   

Dynamic downscaling of 22-year CFS winter seasonal hindcasts with the UCLA-ETA regional climate model over the United States     

Fernando De Sales  Yongkang Xue 《Climate Dynamics》2013,41(2):255-275

This study evaluates the UCLA-ETA regional model’s dynamic downscaling ability to improve the National Center for Environmental Prediction Climate Forecast System (NCEP CFS), winter season predictions over the contiguous United States (US). Spatial distributions and temporal variations of seasonal and monthly precipitation are the main focus. A multi-member ensemble means of 22 winters from 1982 through 2004 are included in the study. CFS over-predicts the precipitation in eastern and western US by as much as 45 and 90 % on average compared to observations, respectively. Dynamic downscaling improves the precipitation hindcasts across the domain, except in the southern States, by substantially reducing the excessive precipitation produced by the CFS. Average precipitation root-mean-square error for CFS and UCLA-ETA are 1.5 and 0.9 mm day^?1, respectively. In addition, downscaling improves the simulation of spatial distribution of snow water equivalent and land surface heat fluxes. Despite these large improvements, the UCLA-ETA’s ability to improve the inter-annual and intra-seasonal precipitation variability is not clear, probably because of the imposed CFS’ lateral boundary conditions. Preliminary analysis of the cause for the large precipitation differences between the models reveals that the CFS appears to underestimate the moisture flux convergence despite producing excessive precipitation amounts. Additionally, the comparison of modeled monthly surface sensible and latent heat fluxes with Global Land Data Assimilation System land data set shows that the CFS incorrectly partitioned most of surface energy into evaporation, unlike the UCLA-ETA. These findings suggest that the downscaling improvements are mostly due to a better representation of land-surface processes by the UCLA-ETA. Sensitivity tests also reveal that higher-resolution topography only played a secondary role in the dynamic downscaling improvement.  相似文献   

Late Quaternary palaeohydrological changes in the large playa Lake Frome in central Australia, recorded from the Mg/Ca and Sr/Ca in ostracod valves and biotic remains     

P. De Deckker  J.W. MageeJ.M.G. Shelley 《Journal of Arid Environments》2011,75(1):38-50

The last 42,000 years of hydrological history of Lake Frome, a large playa located in the arid part of northern South Australia, which is hypersaline and most often dry today, is reconstructed using a combination of ostracod assemblages, other microfossil remains, and the trace elemental composition of the selected halobiont ostracod species of Diacypris and Reticypris.The Mg/Ca and Sr/Ca of ostracod valves from 2 cores relate to significant hydrological changes that affected the lake over time. The reconstruction of the Sr/Ca of the lake’s waters, based on the Sr/Ca of ostracod shells, shows that when the lake fills the waters originate mostly from runoff, not from hypersaline waters located below the lake or the surrounding aquifers. The Last Glacial Maximum saw gypsum deflation from the lake.Prior to 25K yBP, Frome had a stable hydrological regime, permanent water and low salinities, with occasional freshwater conditions between 42 and 33K yBP. From 25 to 20.3K yBP, salinities fluctuated and ephemeral conditions operated. After that, until ∼14.8K yBP, a brine pool was located below the lake and was therefore under a different hydrological regime. Between 13 and 11.2K yBP, wet conditions occurred, but such conditions were not seen again during the Holocene.  相似文献   

Structure and recent evolution of the Hazar Basin: a strike‐slip basin on the East Anatolian Fault,Eastern Turkey     

D. Garcia Moreno  A. Hubert‐Ferrari  J. Moernaut  J. G. Fraser  X. Boes  M. Van Daele  U. Avsar  N. Çağatay  M. De Batist 《Basin Research》2011,23(2):191-207

The Hazar Basin is a 25 km‐long, 7 km‐wide and 216 m‐deep depression located on the central section of the East Anatolian Fault zone (eastern Turkey) and predominantly overlain by Lake Hazar. This basin has been described previously as a pull‐apart basin because of its rhombic shape and an apparent fault step‐over between the main fault traces situated at the southwestern and northeastern ends of the lake. However, detailed structural investigation beneath Lake Hazar has not been undertaken previously to verify this interpretation. Geophysical and sedimentological data from Lake Hazar were collected during field campaigns in 2006 and 2007. The analysis of this data reveals that the main strand of the East Anatolian Fault (the Master Fault) is continuous across the Hazar Basin, connecting the two segments previously assumed to be the sidewall faults of a pull‐apart structure. In the northeastern part of the lake, an asymmetrical subsiding sub‐basin, bounded by two major faults, is cross‐cut by the Master Fault, which forms a releasing bend within the lake. Comparison of the structure revealed by this study with analogue models produced for transtensional step‐overs suggests that the Hazar Basin structure represents a highly evolved pull‐apart basin, to the extent that the previous asperity has been bypassed by a linking fault. The absence of a step‐over structure at the Hazar Basin means that no significant segmentation boundary is recognised on the East Anatolian Fault between Palu and Sincik. Therefore, this fault segment is capable of causing larger earthquakes than recognised previously.  相似文献