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It is generally accepted that end-users’ perception is likely to play a pivotal role for planning and policy consideration. Beach user analysis is thus an important component defining beach management policies. In the framework of a wider project on beaches management, an investigation on residents and tourists was conducted. A survey conducted through questionnaires and interviews was carried out in six coastal municipalities. Results allowed obtaining a clear picture about user profile, perception of the beaches, awareness and attitude about themes related to beach management (i.e. Blue Flag award and beach nourishment practices). Their integration with the “expert knowledge” based analysis allowed to support the definition of beach management interventions.  相似文献   
23.
In this study, we detail procedures to synthesise inclusions of fluids of known composition under diagenetic conditions – low temperatures (50–180 °C) and pressures (2–25 MPa) – hosted by quartz. Pre‐existing microcavities in polished quartz chips were used, decrepitated and rinsed before being healed in an autoclave. Each synthesis required around 4 weeks. A range of biphase liquid–vapour inclusions in the H2O–CH4–NaCl system, similar to natural ones, were synthesised in quartz, varying the content of all three components. The quartz chips were checked before and after synthesis by optical microscopy, microthermometry and Raman spectroscopy. The method was used to build a series of calibration curves relating methane‐to‐water count ratios to the methane content of aqueous fluid inclusions. Good correlation was obtained between Raman band area ratios and the expected CH4 solubilities from equations of state. The chosen procedure's main advantages, compared with other published methods, are as follows: quicker healing of the microfractures at lower temperatures, larger inclusions, simple quartz sample preparation, control of fluid inclusion composition and the use of commercial reactors. Such reference material inclusions allow the calibration of Raman microspectrometers with the objective of PTX reconstruction of palaeofluid migration in petroleum reservoirs.  相似文献   
24.
This article presents evidence on two distinct farming systems—one that utilizes common property pasturelands and another based on private pasturelands—in the Brazilian semi-arid zone. The research is based on a survey carried out in the state of Bahia in 2002. A bivariate analysis was carried out to compare agricultural outputs and income generated in each system. Data suggest that there are no significant differences between the two groups concerning income generation. However, farmers using common pasturelands have more diversified systems and invest more on small-animal husbandry, which are adapted to the dry environment. As a consequence, families that use common pasturelands have a higher consumption of animal protein. These families are thus not necessarily more vulnerable to droughts than those with private pasturelands. Formulating effective institutions to control access to the commons is a strategy pursued by some communities, yet, their ecological sustainability is still unknown.  相似文献   
25.
It is estimated that more than three quarters of the Earth’s biosphere is in perennially cold environments. Despite the extreme environmental conditions of desiccation and freezing, microbes can coloni...  相似文献   
26.
已经认识到,沿西西里和意大利半岛的亚平宁-马格里布褶皱冲断带顶部发育伸展盆地。这些盆地主要形成于上第四纪,推测与伊特鲁里亚弧后盆地的打开有关,这时逆冲前锋部位存在挤压活动。在其沉积下陷内部存在挤压构造。为确定构造类型,对这些盆地中的位于埃格迪岛西南的INVO-2盆地使用密级多道反射剖面测网勘测。INVO-2盆地沿一系列西北-东南向的伸展断层构成,并被地貌高分成两个次级盆地。半地堑极性反转沿两个次级盆地的轴向发育。发育在盆地凹陷内的挤压构造,倾向既有垂直又有平行于盆地轴向的,在一些情况中,这些构造与早期伸展地层的再活动有关。虽然因缺乏井资料不能准确确定挤压期,从盆地的开始到现在,看来挤压是间歇性地发生并夹在以伸展状态为主中。在张性环境中压缩脉冲的起因,我们可以在其毗邻的马格里布碰撞带的动力学中找出答案。  相似文献   
27.
Significant spatial heterogeneity in the abundance and composition of meiofaunal and nematode assemblages was described inside the Genoa-Voltri harbour (Genoa, Italy) in relation to variation in the main environmental variables. In harbour sediments characterized by low Eh values and high organic matter concentrations, total meiofauna abundance was lower (948 ± 919 ind 10 cm−2), nematode individual biomass was higher (0.17 ± 0.07 μg C), kinorhynchs and tanaids were completely absent, and the nematode assemblage was dominated by the genera Terschellingia, Sabatieria (pulchra group) and Paracomesoma. In contrast, in sediment characterized by lower levels of organic pollution, meiofaunal abundance was higher (1085 ± 737 ind 10 cm−2), nematode individual biomass was lower (0.11 ± 0.04 μg C), kinorhynchs and tanaids were present and the nematodes were dominated by the genera Desmodora, Daptonema, Anticoma and Halalaimus.Environmental disturbance as assessed by the analysis of meiofaunal and nematode assemblages and sediment environmental variables changed significantly over a scale hundreds of meters, but did not follow a gradient from the inner to the outer harbour. Analysis of nematode assemblages is proposed as a useful tool for the identification of environmental risk areas which may assist in the development of good planning, monitoring programmes and better management of harbour ecosystems.  相似文献   
28.
Along the southeastern Tyrrhenian Sea margin, the Gioia Basin formed as a result of extensional tectonics at the rear of the Maghrebian thrust belt. In the central part of the basin, mass-transport deposits represent up to 80% of its recent infill. The basin-wide Nicotera slump is the deepest mass-transport deposit present in the basin and was followed by sheet turbidite deposition. Above the turbidite package, a mass-transport complex (MTC) formed through the stacking of different mass-transport deposits due to repeated failures of the continental slope and of a base of slope channel levee wedge, which is still preserved in the western side of the basin. The Villafranca frontally-confined slide, a body mainly consisting of coherent blocks, represents the bulk of the MTC. The failure of the Villafranca slide was due to asymmetric loading of a permeable condensed horizon in the thinnest, distal lateral part of the channel levee wedge. The relatively large thickness of the Villafranca slide caused it to remain confined at its toe region. Smaller scale mass-transport deposits, a debris-flow sheet and a debris-flow lobe, followed the Villafranca slide and were sourced from the same headwall area. Their different run out and internal character are possibly a function of the lithology of the material involved in the collapse. A slab slide, characterized by little internal deformation and frontal contractional ridges, originated when seafloor instability propagated towards the north, causing clockwise rotation of a sediment wedge. Along the linear headwall of the slab slide, a localized upslope failure propagation is shown by a small scale re-entrant. The Sicilian margin, along which the Gioia Basin develops, is characterized by strong differential vertical movements due to ongoing extensional tectonics. The effects of both local and regional strong earthquakes are frequently felt in the area. Thus, slope oversteepening and earthquakes are suggested as the more likely causes for the observed repeated events of seafloor failure. In addition, an evolution of the MTC through larger slides controlled by the migration of uplift of the basin bounding submarine ridge, followed by smaller scale failures due to the consequent slope profile modification, is here advanced.  相似文献   
29.
Member States of the European Union and the Mediterranean Regional Sea need to elaborate national strategies for coastal management according to ICZM principles and to undertake national stock-taking, which must consider major actors, laws and institutions influencing the management of their national coastal zone. However, different approaches to coastal management and defence and various degrees of development and implementation of national ICZM strategies can be found. The research presented in this article aims to analyze the different situations and to contribute to the further development of a common approach in terms of methodology to establish stakeholder and users participation in ICZM. An extensive survey was conducted in five pilot sites along the European Mediterranean coastal zone (Greece, Italy and France) show beach visitors’ perception of ICZM, coastal erosion and coastal defence systems, and beach visitors’ Willingness To Pay (WTP) for beach defence. The survey yielded important information for coastal and beach managers. Surprisingly, the level of awareness about generic Coastal Zone Management was found to be rather low in all regions except Riccione Southern beach, Emilia-Romagna Region. In the Languedoc-Roussillon Region, this is justified by the fact that most of the respondents were not local people or beach visitors (other than recreational day-visitors). As regards coastal erosion it appears significant that, despite the lack of awareness demonstrated overall by stakeholders in the Region of East Macedonia and Thrace, visitors respond very positively to definitions and show awareness of the erosion process in their coastal system. In conclusion, in order to raise public awareness about ICZM, erosion and coastal defence systems, it is suggested that education, training and public awareness should be promoted as well as identification of local needs for the implementation of specific demand-driven studies.  相似文献   
30.
A detailed multibeam coverage of the eastern offshore of Lipari Island(Aeolian arc) has permitted its subdivision into two sectors with differentmorphobathymetric features. In the northern one, numerous, large, previouslyundetected rhyolitic lava flows have been identified. In the southern one, aconical pyroclastic and epiclastic edifice built on top of afan-shaped lava field has been discovered. Since some of theseoffshore features have no analogues on land, their recognition has furnishednew information about the volcanic processes that built the eastern portionof Lipari Island. In particular, the finding of a huge volume of offshorerhyolitic lava flows, largely exceeding the amount of this kind of lavas onland, shows that the contribution of rhyolitic products in the building ofthe Lipari apparatus has been up to now underestimated. More generally, thecomparison between the land and the offshore units of Lipari volcanicapparatus indicates that a better investigation of the submarine portions ofvolcanic islands can reveal new, unforeseen aspects and greatly enhance ourknowledge about their evolution.  相似文献   
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