41 research outputs found
Morphological cells in the Ragusa littoral (Sicily, Italy)
Geomorphologic information, topographic maps
(dated 1967), aerial photographs (dated 1999 and 2008), and
spatial analysis procedures were used to investigate a 90 km
long coastal sector in South Sicily (Italy). Information was
obtained on coastal erosion/accretion areas, general sediment
circulation pattern and littoral cell distribution. Human-made
structures and natural headlands constituted important artificial
limits dividing littoral in morphological cells. Ports and
harbours were observed at Scoglitti, Punta Secca, Marina di
Ragusa, Donnalucata and Pozzallo. Most of them worked as
âtransitâ limits which interrupted predominant, eastward directed
sedimentary transport, this way generating accretion in
updrift (west) side of mentioned structures and erosion in
downdrift (east) side. During the 1967â2008 period, about
62,000 m2 and 42,000 m2 of beach surface were respectively
formed updrift of Scoglitti and Donnalucata ports. The construction
of Pozzallo port gave rise to the formation of a
âconvergentâ limit which favoured large accretion
(94,000 m2) east of port structure. Most important natural
structures were observed at Punta Zafaglione, P. Braccetto
and Cava dâAliga. The knowledge of littoral cell distribution
acquires a great importance for appropriate management of
coastal erosion processes which may be mitigated installing
by-passing systems in ports and harbours and carrying out
nourishment works in eroding areas, often located downdrift
of ports and harbours (when these structures work as transit
limits) and in central part of littoral cells (when these structures
work as convergent limits)
Error determination in the photogrammetric assessment of shoreline changes
The evaluation of error or uncertainty in shoreline change studies is an issue of
prime importance for providing an adequate framework for calculated rates of change and to allow the establishment of threshold values above which the rates would be significant. In this note, a practical, easy-to-use method is presented to estimate error involved in the calculation of shoreline changes on aerial photographs, including the three most used types of shoreline indicators: high water line, dune/cliff toe and cliff top. This approach takes into account the specific characteristics of each shoreline proxy, such as relief in the case of
the cliff top or tidal oscillations in the case of the high water line. At the same time it includes the error components that are independent from the proxy, basically related to the technical aspects of the process such as photo scanning and georeferencing. A practical example of application of the method is provided for several types of data inputs, based on shoreline changes around the Bay of CĂĄdiz (SW Spain)
C-H functionalization of sp<sup>3</sup> centers with Aluminum:A computational and mechanistic study of the baddeley reaction of Decalin
Lost value assessment of bathing beaches due to sea level rise: a case study of the Mediterranean coast of Israel
Late Quaternary beach deposits and archaeological relicts on the coasts of Cyprus, and the possible implications of sea-level changes and tectonics on the early populations
Geo-archaeological markers reveal magnitude and rates of Israeli coastal cliff erosion and retreat
Increasing social engagement in children with high-functioning autism spectrum disorder using collaborative technologies in the school environment
Late Quaternary beach deposits and archaeological relicts on the coasts of Cyprus, and the possible implications of sea-level changes and tectonics on the early populations
<p>Late Pleistocene beach deposits in 22 selected sites around Cyprus demonstrate the vertical changes in the Earth's crust in
that island over the last 125 ka. The beach/shallow-marine deposits were observed on the abraded coastal cliffs at 3â22 m
above the present sea-level. They overlie Pliocene marls, and some of them contain the Senegalese marine gastropods <em>Persististrombus latus</em>, <em>Bursa granularis</em> and <em>Conus ermineus</em> that no longer live in the Mediterranean. These are index fossils for the Marine Isotope Stage (MIS) 5e in the Mediterranean
and, as such, suggest an uplift of up to 15.5 m over about the last 125 ka: that is a maximal rate of 0.12 mm a<sup>â1</sup>. These findings are in accordance with Holocene beachrocks, abrasion platforms, wave notches and Roman/Byzantine fish tanks
that retained their elevations, and thus enable the reconstruction of the coast encountered by the early colonizers. While
the maximal uplift since the early Holocene has been minor and did not exceed 1.2â1.5 m, the sea-level changes have reached
40â50 m. The transition between the impermeable Pliocene marls and the porous Late Pleistocene deposits above them is the
origin of freshwater springs and associated vegetation. The early colonizers seemed to recognize the potential of that essential
permanent source of water and excavated wells, the earliest wells known so far. The locations of the Early Neolithic settlements
(Mylouthkia and Akanthou) adjacent to visible water springs along the coastal cliffs may not be incidental. Not surprisingly,
recent wells dug in the coastal Pleistocene deposits rely on the very same hydrological setting.
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