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991.
Sociospatial information is critical to marine and coastal ecosystem management. The Hawaii Coastal Uses Mapping Project used a participatory geographic information systems (PGIS) methodology to gather local knowledge regarding the location and intensity of coastal human activities in Hawaii's priority sites for coral reef management. PGIS provided an efficient and effective means of obtaining information in a data-poor context, particularly at a scale and location where considerable local knowledge is held by community members and resource users. We detail the PGIS methods developed to collect sociospatial data on human uses in the project regions and discuss important considerations regarding the practice of PGIS that emerged from the mapping process, as well as implications for the production and documentation of spatial knowledge. Key themes include: issues of scale and appropriateness in using PGIS as a method for mapping human coastal and marine activities; data validity, authority, and the nature of local knowledge; community trust, engagement, and collaboration; and utility for coral reef management. While several factors limit local agencies' ability to use this spatial information to date, natural resource managers found the participatory mapping process to be highly valuable for stakeholder identification and engagement, and the maps provide a resource to state and federal managers to better understand the human implications of future management scenarios. 相似文献
992.
The influence of environmental variability of a coastal lagoon ecosystem on genetic diversity and structure of white seabream [Diplodus sargus (Linnaeus 1758)] populations
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Raquel Hernández‐García Irene Muñoz Antonio López‐Capel Concepción Marcos Ángel Pérez‐Ruzafa 《Marine Ecology》2015,36(4):1144-1154
As coastal lagoons serve as nursery areas for some marine and estuarine fish, selective pressures of these brackish or hypersaline lagoons may influence the genetic structure of species and populations. We examined spatial and temporal genetic patterns at eight microsatellite loci in white seabream [Diplodus sargus (Linnaeus 1758)] recruits from the Mar Menor (Southeast Spain) and compared these loci with those in coastal populations from the open sea, observing a high degree of genetic diversity and spatio‐temporal genetic stability. However, the results suggest the presence of subpopulations or genetic substructures in the Mar Menor D. sargus population that could be interpreted as a homogeneous mixture of individuals from three differentiated subpopulations in the Mediterranean and evidence of the Wahlund effect. It also suggests that D. sargus adults return to their original spawning habitat, thus conserving the genetic differences among the respective populations over time. Overall, this study demonstrates the importance of the Mar Menor coastal lagoon as a nursery area for the conservation of genetic diversity of D. sargus populations. 相似文献
993.
《Marine Policy》2015
Feedbacks occur when advocates engage to clarify the implementation of a policy innovation such as the requirement that federal activities be consistent with objectives of state coastal management plans. Discrete policy feedbacks include advocacy, litigation, appeals of decisions as well as other activities inserted into policy implementation by interests or government agencies acting in their behalf. Feedback analysis is applied to the time after the passage of the 1972 U.S. Coastal Zone Management Act. Conflicts after passage of the law resulted in a negative feedback in the form of a Supreme Court decision in 1984 and a subsequent positive feedback through the 1990 revision of the law effectively reversing the Court decision. New insights documented here suggest that feedback switching, wherein old disputes are moved to new arenas, provides the greatest opportunity for overcoming negative feedbacks that could diminish or eliminate the policy innovation. Furthermore observing feedbacks through time and across multiple policy spaces as demonstrated here provides a robust interpretation of policy evolution from a new perspective. This analysis demonstrates how feedbacks convert a voluntary state program into one with authority over certain federal actions. These findings will be important for other areas of coastal policy and, more broadly, policy evolution in general. 相似文献
994.
《Geoforum》2015
Based on an examination of Israel’s territorial conceptions, strategies, and achievements since the establishment of the state, this article shows how state territoriality subsumes ideology and political agendas and may, under certain circumstances, lead the state to negate its very self-conceptions and harm its own perceived interests. Its analysis pays special attention to the state’s inadvertently produced territories of negation, which run counter to its own conception of territoriality, and considers the kind of social–spatial entities produced by the state. It also considers Israeli territoriality’s more recently asserted goal of shaping Israel as a Jewish and democratic state, in addition to the goals of controlling Jerusalem and Judaizing the Galilee and the Negev. To illustrate the theoretical assertion that discriminatory and marginalizing state territoriality has the distinct potential to bring about its own negation, the article concludes with two prominent expressions of this phenomenon. The first is manifested in green-line Israel, where the state’s territorial policies and the resulting marginalization of the Palestinian minority has resulted in collective resistance against the state and its policies, basic Jewish-Israeli symbols such as the anthem and the flag, and Israel’s very definition as a Jewish State. The second is manifested in Israel’s inadvertent creation of bi-national spaces both within Israel proper and in East Jerusalem and the West Bank, indirectly promoting the solution of a single bi-national state and posing a serious challenge to the very goals that Israeli territoriality has consistently strived to achieve. 相似文献
995.
Forced regressive deposits of a deglaciation sequence: Example from the Late Quaternary succession in the Lake Saint‐Jean basin (Québec,Canada)
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Alexis Nutz Jean‐François Ghienne Mathieu Schuster Pierre Dietrich Claude Roquin Murray B. Hay Frédéric Bouchette Pierre A. Cousineau 《Sedimentology》2015,62(6):1573-1610
Differentiating between forced regressive deposits from deglacial periods in high latitude domains and forced regressive deposits from the onset of glacial periods in low latitude domains is fundamental for the accurate interpretation of glacial cycles within the geological record and then for the reconstruction of palaeogeography and palaeo‐climate. A forced regressive deglacial sequence is documented from the Lake Saint‐Jean basin (Québec, Canada). In this area, the Late Pleistocene to Holocene sediments have recorded the Laurentide ice sheet retreat accompanied by the invasion of marine waters (Laflamme Gulf) from ca 12·9 cal kyr bp . Subsequently, fluvio‐deltaic and coastal prograding wedges were deposited; they followed the base‐level fall due to glacio‐isostatic rebound. This succession, representing a transition from glacial to post‐glacial periods within a previously glaciated area, was investigated through recent mapping, preserved landforms, facies analysis, and new optical stimulated luminescence and radiocarbon dates. Three basin‐scale geological sections share a common lower part made of isolated ice‐contact fan deposits overlying bedrock. Throughout the entire basin, ice‐contact fans are capped by glacimarine muds. Above, fluvial and coastal prograding systems were deposited and evolved through four steps: (i) deltaic systems progressively increased in width; (ii) coastal influence on sedimentation increased; (iii) hydrographic drainage systems became more organised; and (iv) deltas graded from steep (Gilbert delta) to low‐angle foresets (mouth‐bar delta). Deposited during the base‐level fall from glacio‐isostatic rebound, the complete succession has been designated as a single falling stage system tract referred to as a deglacial falling stage system tract. It is representative of a deglaciation sequence in areas previously covered by ice during glacial periods (i.e. medium to high latitude domains). Diagnostic criteria are provided to identify such a deglacial falling stage system tract in the geological record, which may aid identification of previously unknown glacial cycles. 相似文献
996.
Precise indices based on n-alkane signatures were developed in order to determine the sources and composition of sedimentary organic matter (SOM) in coastal systems. The Arcachon Bay (France), a well-studied temperate lagoon, was used as an example of a complex coastal system sheltering a wide diversity of OM sources. Three main groups of sources were well discriminated from their n-alkane signatures: seagrass (Zostera sp.) produced mainly n-C17, n-C19, n-C21, n-C23 and n-C25 alkanes, algae (Rhodophyta, Chlorophyta) produced n-C15 and n-C17 and the terrigenous input [Quercus sp., Spartina sp. and river suspended particulate OM (SPOM)] was characterized by n-C25, n-C27, n-C29, n-C31 and n-C33. From the above and literature n-alkane fingerprints, we developed a set of indices (n-alkane ratios) to quantify the contribution of these three major sources of the SOM. At the Arcachon Bay scale, they indicated that SOM was composed mainly of seagrass (ca. 53 ± 19%) and terrestrial (ca. 41 ± 17%) material, followed by algae (ca. 6 ± 9%). Moreover, the new n-alkane indices exhibited more relevant spatial patterns than classical ones – the TAR (C27 + C29 + C31/C15 + C17 + C19; terrestrial to aquatic ratio) and the Paq (C23 + C25/C23 + C25 + C29 + C31; aquatic plant %) – with a greater contribution from marine sources in the central part of the lagoon where a high density of Zostera seagrass was observed. Therefore, the development of precise indices adapted to the local diversity of OM sources is needed when using n-alkanes for quantifying the source composition of SOM in complex coastal systems. 相似文献
997.
福建石狮白垩纪花岗岩与中基性脉岩的年代学与地球化学 总被引:1,自引:1,他引:0
在我国华南地区广泛发育了白垩纪岩浆活动,形成了大面积的花岗岩和多期侵位的中基性和酸性脉岩。其中中基性脉岩被认为是华南白垩纪多期伸展作用的标志之一。本文对采自福建沿海石狮地区的石狮和东埔两地的花岗岩和侵入的中基性脉岩进行了锆石U-Pb年代学和Hf同位素以及岩石元素地球化学研究。石狮地区的花岗岩和花岗闪长岩为中钾-高钾钙碱性、弱过铝质岩石,2个锆石U-Pb年龄分别为105.3±1.0Ma和105.1±0.5Ma,2个花岗岩的锆石εHf(t)为-0.9~+2.0;侵入的脉岩为辉绿岩和闪长岩,属于准铝质中钾-高钾钙碱性岩石,2个闪长岩的锆石U-Pb年龄分别89.5±1.5Ma和96.1±1.2Ma,脉岩的εHf(t)为+1.3~+5.0。石狮地区花岗岩和脉岩显示轻重稀土中等分馏和弱的Eu异常,花岗岩稀土总量明显低于脉岩,岩石大离子亲石元素富集、高场强元素亏损,显示岛弧岩浆岩的地球化学特征;微量元素判别(Ta/Hf-Th/Hf,Zr-Zr/Y)表明石狮地区的岩脉产于大陆边缘裂谷环境或板内构造环境,脉岩应是古太平洋俯冲的大陆边缘背景之上,俯冲结束后转入大陆边缘伸展作用的标志。福建沿海厦门-石狮-晋江地区的伸展作用发生在87~96Ma,与华南区域上多期伸展作用中~90Ma的伸展作用吻合。 相似文献
998.
Margo Kleinfeld 《GeoJournal》2005,64(4):287-295
This paper describes the changing discourses of territory in Sri Lanka and their utility in conflict relations. The primordial
homeland has been at the center of Sri Lanka’s armed struggle, in which both Sinhalese and Tamil nationalisms have used claims
of ancient and ethnically determined territories to justify their right to self-determination, territorial sovereignty, and
armed struggle. This identity–territory nexus based on historical argument has been destabilized in Sri Lanka, however. Scholarly
findings suggest that historical linkages between ethnicity and territory in Sri Lanka are highly problematic and are no longer
effectual means for adjudicating territorial desires in Sri Lanka and producing stable homelands. I argue that rights-based
territorial discourses have emerged to enhance the old historical justifications for territorial authority. New narratives
based upon fulfilling or denying human rights have been put to work linking authority to territory based upon moral fitness
and unfitness, political legitimacy and illegitimacy, and ultimately, upon which political actor deserves to rule the territorially
bound population under its control. The first part of the paper examines historical narratives linking national homelands
to identity as well as scholarly work that deconstructs this linkage. In part two, external sovereignty and political legitimacy
are discussed as the starting point for understanding how rights-based discourses justify territorial claims. In part three,
accusations related to human rights violations are described as an important vehicle for shaming political adversaries, undermining
their legitimacy, and making and unmaking territorial claims in Sri Lanka. 相似文献
999.
To study sediment suspension above ripples under the combined action of waves and currents, a three‐dimensional numerical model has been developed based on the use of FLUENT software, and an external sediment transport model. The computer model has been tested against laboratory measurements involving oscillatory wave motion, as well as cases of co‐linear waves with following and opposing currents, with satisfactory results. Compared with the situation in which only waves are present (called waves‐alone cases), the effects from the steady current on both vortex shedding and sediment suspension above ripples have clearly been revealed by the model results. In particular, the vortices generated in combined waves and currents tend to stay low in the trough area of the ripple and are ejected earlier than those in the waves‐alone case at both the ripple crest and trough, which leads to concentration peaks at different phases and with different magnitudes. The model was also applied to a field case from a multi‐barred, dissipative beach at Egmond‐an‐Zee, in the Netherlands, to investigate the influences of a long‐shore current on cross‐shore sediment transport. The model results show reasonable overall agreement with the field measurements, as well as the important effects of the three dimensional flow structure on the sediment entrainment process close to the ripple surface, which is very difficult to observe in such detail in field studies. 相似文献
1000.
The effects of the interaction among sea water, sediment, backfill-soil and coastal structures (embankments) were included in the present study. The formulation is derived from fundamental theories in various fields, including marine hydrodynamics, flow in porous medium, and structural dynamics. The hybrid finite-difference and finite element methods were used in the analysis. The finite-difference method was used to calculate the nonlinear hydrodynamic pressures of sea water as well as the pore water in the sediment acting on the coastal embankment faces by seismic-wave actions. The fluid-filled solid mixture was used to model sediment and back-fill soil and the corresponding dynamic responses were also evaluated by finite difference method. The dynamic response of the coastal structures was calculated by finite element method. The numerical results are presented for various water depths and ground motion intensities. The significant dynamic forces on coastal structures were calculated during earthquakes and the possible sliding of the coastal embankment will occur and the special foundation treatment should be made. 相似文献