An Integrated Coastal Sediment Management Plan: The Example of the Tuscany Region (Italy)

This paper presents the results of a study carried out to support the Region of Tuscany Coastal Sediment Management Plan, with the main aim of establishing the sediment budget considering the time span from 1981-1985 to 2005 for the 56 coastal sectors into which the 215 km-long continental sandy coast of Tuscany (Italy) was divided. The sand stability (according to a stability index) and colour compatibility (according to the CIEL*a*b* colour space with an acceptability range conforming to national guidelines) were determined in order to assess the possibility of using the available sediment in accreting sectors to nourish the beach in eroding areas. Only in two cases-i.e., the updrift of a harbour (at Viareggio) and in a convergence zone (at Marina di Pietrasanta)-are the volumes of sufficient magnitude to support a large nourishment project; however, the mean sand size is too small to guarantee efficient nourishment, even with medium-term stability. In contrast, the colour difference, in most of the cases, was shown to be acceptable. Other small sediment stocks, suitable for colour but not for grain size, can be used for periodic ephemeral nourishment works to support seasonal tourist activities. The limited resources available make it necessary to adopt a plan for their optimal use from a regional perspective. This kind of study is of great interest for the proposal of sound management actions to counteract the increasing erosion processes linked to climate change phenomena and human effects on rivers and coastal systems

Experiencias en gestión de la erosión costera en Italia: casos prácticos de Sicilia y Toscana

El trabajo presenta los resultados de diferentes estudios llevados a cabo mediante fotos aéreas y mapas de diferentes escalas y años en Sicilia y en Toscana (Italia). En detalle, se describen los procesos de erosiónJacreción observados y las intervenciones llevadas a cabo para contrarrestarlos. Finalmente se analiza la evolución de las técnicas de defensa costera empleadas en las últimas décadas en Italia, resaltando el cambio de tendencia observado, es decir el remplazo de las obras de protección rígidas por obras de regeneraciónThe paper deals with the results of several works carried out in Sicily and Tuscany (Italy) by the means of aerial photographs and maps of different years and scales. In detail, it describes the erosion/accretion problems as well as the solutions adopted to solve them. Further, it is analyzed the evolution of defense techniques used in Italy in last decades, in order to highlight the change of trend recoded, that is the replacement of hard solutions by new, soft solutions, e.g. beach nourishment

Detector-based measurements for QFT: two issues and an AQFT proposal

We present and investigate two issues with the measurement scheme for QFT presented by J. Polo-Gomez, J. J. Garay and E. Martin-Martinez in "A detector-based measurement theory for quantum field theory". We point out some discrepancies that arise when applying the measurement scheme to contextual field states. Also, we show that $n$-point function assignments based on local processing regions lead to inconsistencies for some choices of spacetime points, e.g. across measurement light cones. To solve these two issues, we propose a modification to the measurement scheme. The proposal is a rule for assigning (equivalence classes of) algebraic states to spacetime regions. In this way, the measurement-induced collapse is represented in the formal expression of the states, and $n$-point functions can be consistently evaluated across any region having a definite causal relation with measurements.Comment: 16 pages, 4 figure

Threshold size for the emergence of a classical-like behaviour

In this work we design a procedure to estimate the minimum size beyond which a system is amenable to a classical-like description, i.e. a description based on representative points in classical phase-spaces. This is obtained by relating quantum states to representative points via Generalized Coherent States (GCS), and designing a POVM for GCS discrimination. Conditions upon this discrimination are defined, such that the POVM results convey enough information to meet our needs for reliability and precision, as gauged by two parameters $\epsilon$, of our arbitrary choice, and $\delta$, set by the experimental apparatus, respectively. The procedure implies a definition of what is meant by "size" of the system, in terms of the number $N$ of elementary constituents that provide the global algebra leading to the phase-space for the emergent classical-like description. The above conditions on GCS discrimination can be thus turned into $N>N_{\rm t}(\epsilon,\delta)$, where $N_{\rm t}(\epsilon,\delta)$ is the threshold size mentioned in the title. The specific case of a magnetic system is considered, with details of a gedanken experiment presented and thoroughly commented. Results for pseudo-spin and bosonic systems are also given

Mathematical Reconstruction of Eroded Beach Ridges at the Ombrone River Delta

Several remotely sensed images, acquired by different sensors on satellite, airplane, and drone, were used to trace the beach ridges pattern present on the delta of the River Ombrone. A more detailed map of these morphologies, than those present in the literature, was obtained, especially at the delta apex, where beach ridges elevation in minor. Beach ridges crests, highlighted through image enhancement using ENVI 4.5 and a DTM based on LiDAR data, were then processed with ArcGIS 9.3 software. Starting from this map, a method to reconstruct beach ridges segments deleted by the transformations of the territory is proposed in this paper. The best crest-lines fitting functions were calculated through interpolation of their points with Curve Expert software, and further extrapolated to reconstruct the ridges morphology where human activity, riverbed migration, or coastal erosion eliminated them. This allowed to reconstruct the ridges pattern also offshore the present delta apex, where the shoreline retreated approximately 900 m in the last 150 years. Results can be further used to implement conceptual and numerical models of delta evolution

Predicting population size at large scale: The case of two large felids

Approaches that allow capitalizing on local population estimates to derive global population estimates with associated uncertainty are urgently needed, especially for naturally rare species of conservation concern. Here we used published population density estimates to predict large-scale density patterns and derive global population estimates for two species of large felids, the leopard and the tiger. We modelled population density for the leopard (n = 392) and the tiger (n = 547) as a function of environmental and anthropogenic variables, while controlling for differences in sampling method and sampling area, time of data collection, spatial autocorrelation, subspecies and political protection. We used Bayesian inference to generate a distribution of plausible population sizes. Both species showed higher densities in high productivity areas, the leopard being more abundant in high precipitation, high level of terrain roughness and agricultural areas, and the tiger in areas with low croplands and low roughness. Primary roads density showed a negative effect on both species. Secondary roads density was associated to higher densities for the leopard but lower densities for the tiger. Livestock biomass showed a humped relationship with tigers’ densities. Temporal trends in average density were negative for the tiger, experiencing an average decline of 34% (IQR: 11% − 53%). In contrast, the trend for leopards showed a marginal, yet uncertain, increase in recent years 21% (IQR: − 5% − 57%). We predicted a global population estimate of 261,636 (IQR = 146,768 − 461,512) and 5201 tigers (IQR = 2596 − 10,460). Large-scale models of population density that rely on unstructured data can contribute to our understanding of species ecology, produce robust population size estimates for conservation assessment and inform large-scale conservation planning. At the same time, the uncertainty around these estimates highlights the limited knowledge available for these species which should be accounted for in conservation assessments