Climate Change and the Mediterranean Southern Coasts

This chapter deals with climate change effects in the Mediterranean littoral of Morocco, which is one of the most vulnerable countries within the Mediterranean region, especially the low-lying areas located in the eastern, i.e., Nador and Saidia areas, and western parts, i.e., Tangier and Tetouan areas. The different aspects of climatic change characteristics and impacts are also analysed, including: sea level rise (SLR) trend in the Mediterranean littoral of Morocco; coastal erosion and flooding hazards; water management problems; and agricultural and tourist activities. It is established that appropriate vulnerability assessment and adaptation strategies to SLR and climate change are required at regional and national scale in Morocco, to improve the tools for correct coastal zone management

String order and adiabatic continuity of Haldane chains and band insulators

The ground state of spin-1 Haldane chains is characterized by the so-called string order. We show that the same hidden order is also present in ordinary one-dimensional band insulators. We construct a family of Hamiltonians which connects adiabatically band insulators to two topologically non-equivalent spin models, the Haldane chain and the antiferromagnetic spin-1/2 ladder. We observe that the localized spin-1/2 edge-state characteristic of spin-1 chains is smoothly connected to a surface-bound state of band insulators and its emergence is not related to any bulk phase transition. Furthermore, we show that the string order is absent in any dimensions higher than one.Comment: 6 pages, 7 figures. Appendix about charge string orders added. Version as publishe

Fragility of String Orders

One-dimensional gapped systems are often characterized by a 'hidden' non-local order parameter, the so-called string order. Due to the gap, thermodynamic properties are robust against a weak higher-dimensional coupling between such chains or ladders. To the contrary, we find that the string order is not stable and decays for arbitrary weak inter-chain or inter-ladder coupling. We investigate the vanishing of the order for three different systems: spin-one Haldane chains, band insulators, and the transverse-field Ising model. Using perturbation theory and bosonization, we show that the fragility of the string order arises from non-local commutation relations between the non-local order parameter and the perturbation.Comment: 7 pages, 3 figures. Published versio

Coastal vulnerability in the Mediterranean sector between Fnideq and M’diq (North of Morocco)

This study assessed coastal vulnerability to erosion processes along a 24- km-long littoral with different levels of human occupation. An aerial photogram- metric flight and a Quickbird satellite image were used for mapping land uses and reconstructing coastal evolution from 1986 to 2003. Maximum erosion (- 2.48 myr−1) was recorded south of Marina Kabila port and maximum accretion (+2.25 myr−1) south of Marina Smir port. Erosion/accretion rates have been divided into five categories and land uses have been mapped and divided into three categories. Coastal vulnerability has been assessed by combining coastal trend with land-use categories: 10% of the littoral recorded “very high” vulner- ability, 29% recorded “high” vulnerability, and 61% of the investigated littoral presented “null” and “low” vulnerability. The “Imminent Collapse Zone”, i.e. the littoral zone threatened by imminent erosion, presented mean values of 10.34 m, with maximum and minimum values of 15.3 and 7.6 m, respectively. Several human structures and activities are located within the imminent collapse zone and consequently will be threatened by severe erosion in near future

Coastal sensitivity/vulnerability characterization and adaptation strategies: A review

Coastal area constitutes a vulnerable environment and requires special attention to preserve ecosystems and human activities therein. To this aim, many studies have been devoted both in past and recent years to analyzing the main factors affecting coastal vulnerability and susceptibility. Among the most used approaches, the Coastal Vulnerability Index (CVI) accounts for all relevant variables that characterize the coastal environment dealing with: (i) forcing actions (waves, tidal range, sea-level rise, etc.), (ii) morphological characteristics (geomorphology, foreshore slope, dune features, etc.), (iii) socio-economic, ecological and cultural aspects (tourism activities, natural habitats, etc.). Each variable is evaluated at each portion of the investigated coast, and associated with a vulnerability level which usually ranges from 1 (very low vulnerability), to 5 (very high vulnerability). Following a susceptibility/vulnerability analysis of a coastal stretch, specific strategies must be chosen and implemented to favor coastal resilience and adaptation, spanning from hard solutions (e.g., groins, breakwaters, etc.) to soft solutions (e.g., beach and dune nourishment projects), to the relocation option and the establishment of accommodation strategies (e.g., emergency preparedness)

Susceptibility of rat retina acyl-CoA: 1-acyl-sn-glycero-3-phosphocholine O-acyltransferase and CTP:phosphocholine cytidylyltransferase activity to lipid peroxidation and hydroperoxide treatment

AbstractTwo enzyme activities involved in phospholipid metabolism in the rat retina were determined after in vivo and in vitro peroxidation according to several model systems. The in vivo models were based on: (i) intravenous administration of a sonicated emulsion of phospholipid and linoleate photooxidized mixture to normal rat for a period of one week; (ii) acute injection of Fe2+ solution (20 mM) or (iii) 0.5 mg of hydroperoxylinoleate into the vitreous body, and collection of retinal tissue 4 h or 4 days later, respectively. Oleoyl CoA:lysophosphatidylcholine acyltransferase activity was unchanged or exhibited significant inhibition. On the contrary, CTP:phosphocholine cytidylyltransferase activity was stimulated. By incubating in vitro the retina with: (i) Fe2+-ascorbate; (ii) photooxidized phospholipid mixture (0.1–5 mM) or individual phospholipid classes; (iii) hydroperoxylinoleate (0.25–2 mM), with or without Fe2+, a significant inactivation of acyltransferase (six-fold maximum loss of initial activity) and a slight stimulation of cytidylyltransferase were seen. Altogether, the results suggest that in situ oxygen radical generation by a variety of agents irreversibly perturbs enzymes and/or membrane structures in which the enzymes are inserted; these events may be a causal factor in retinal degeneration accompanying some ocular diseases

Coastal Scenic Quality Assessment of Moroccan Mediterranean Beaches: A Tool for Proper Management

This paper focuses on the study of landscape quality of Moroccan Mediterranean coastal areas, with a view to distinguishing exceptional beaches with high scenic value. The main characteristics of 50 beaches along the studied coast were assessed using a coastal scenic evaluation system based on a set of 26 selected parameters, including physical (18) and human (8) parameters. Each parameter was examined via a five-point rating scale, ranging from presence/absence or poor quality (1) to excellent quality (5). A decision index (D) is afterward obtained and used to classify sites into five classes: Class I: D >= 0.85, which included 9 sites (18%); Class II: 0.85 > D >= 0.65, 10 sites (20%); Class III: 0.65 > D >= 0.40, 8 sites (16%); Class IV: 0.40 > D >= 0.00, 16 sites (32%); and Class V: D < 0.00, 7 sites (14%). The sites of Belyounech 2, Maresdar, El Hwad, and Dalya are the best examples of Class I and represent extremely attractive coastal landscapes. The sites of Ghandouri, Tangier Municipal, M'Diq, Martil, and Tangier Malabata are examples of degraded urban sites that are very unattractive due to high human pressures. Management efforts in Moroccan coastal landscapes can strengthen the control of human activities and improve the scenic value of the sites. Class II beaches, such as Mrisat, Souani, Taourirt, and Sfiha, could improve and upgrade to Class I through litter cleaning and a regular maintenance program. Using the same principle, Class III sites, such as Sidi Amer O Moussa and Sidi Driss, could improve and upgrade to Class II. Indeed, litter and sewage appear as the main factors of degradation of Moroccan coasts, and many excellent beaches are strongly affected by them. This should be a wakeup call to the Moroccan authorities to take urgent and appropriate management measures

Low-energy local density of states of the 1D Hubbard model

We examine the local density of states (DOS) at low energies numerically and analytically for the Hubbard model in one dimension. The eigenstates represent separate spin and charge excitations with a remarkably rich structure of the local DOS in space and energy. The results predict signatures of strongly correlated excitations in the tunneling probability along finite quantum wires, such as carbon nanotubes, atomic chains or semiconductor wires in scanning tunneling spectroscopy (STS) experiments. However, the detailed signatures can only be partly explained by standard Luttinger liquid theory. In particular, we find that the effective boundary exponent can be negative in finite wires, which leads to an increase of the local DOS near the edges in contrast to the established behavior in the thermodynamic limit.Comment: 6 pages, 4 figures, more information can be found at http://www.physik.uni-kl.de/eggert/papers/index.htm

Characteristics and coastal effects of a destructive marine storm in the Gulf of Naples (southern Italy)

Destructive marine storms bring large waves and unusually high surges of water to coastal areas, resulting in significant damages and economic loss. This study analyses the characteristics of a destructive marine storm on the strongly inhabited coastal area of Gulf of Naples, along the Italian coasts of the Tyrrhenian Sea. This is highly vulnerable to marine storms due to the accelerated relative sea level rise trend and the increased anthropogenic impact on the coastal area. The marine storm, which occurred on 28 December 2020, was analyzed through an unstructured wind-wave coupled model that takes into account the main marine weather components of the coastal setup. The model, validated with in situ data, allowed the establishment of threshold values for the most significant marine and atmospheric parameters (i.e., wind intensity and duration) beyond which an event can produce destructive effects. Finally, a first assessment of the return period of this event was evaluated using local press reports on damage to urban furniture and port infrastructures