Alexandria is located on the Mediterranean coast of Egypt, bordered by Egypt's Western Desert and the fertile Nile Delta. For many centuries, Alexandria was the major port city in the Eastern ...Mediterranean and it has been repeatedly struck by natural disasters, such as earthquakes, tsunamis and land subsidence, in its ~2400-year history. This book focuses on the geomorphological and archaeological evidence on the coastal zone of Alexandria, attempting to provide a comprehensive review of its evolution, taking into consideration long-term and short-term factors.
The book provides an extensive background on the geomorphology and recent geoarchaeological history of Alexandria, discussing historical maps and natural disasters. In the coastal area of Alexandria there is numerous archaeological evidence, such as burial sites, quarry activities and ancient building remnants, as well as geomorphological features, all revealing a complex evolution of the coastal zone. New evidence, such as fish tanks and ship wrecks in order to discuss the Late Holocene evolution of the coastal zone. Detailed illustrations and maps accompany the book chapters providing the reader the opportunity to gain an extensive view of Alexandria's features.
Geomorphological and sedimentological indicators are often used to reconstruct not only coastal evolution, but also relative sea level changes. In this work, we studied the coastal sediments of ...Psatha bay (Alkyonides Gulf, Greece) and beachrock outcrops in order to reconstruct the coastal evolution of the area. The drillings analysis included stratigraphy, sediment texture and radiocarbon dating. Detailed mapping of the beachrocks was accomplished using DGPS-GNSS, as well as mineralogical analysis and OSL dating of beachrock samples. The new beachrock index points indicate a sea level that fell by 0.64 ± 0.13 m since 2200 ± 210 years BP and by 0.95 ± 0.13 m since 4160 ± 320 years BP, as a direct result of its location near the uplifting footwall of Psatha fault, suggesting further a rate of tectonic uplift of ~0.26 mm/yr for the late Holocene.
Virtual reality is a technological development that, among others, has revolutionized Earth sciences. Its advantages include an opportunity to examine places otherwise difficult or impossible to ...access and it may also become an important component of education, fostering a better understanding of processes and landforms, geohazard awareness, and an appreciation of geoheritage. This paper reports on the GeoVT project, which aims to create a platform to build and disseminate Virtual Field Trips (VFTs) focused on geomorphology, natural hazards associated with geomorphological processes, and geoheritage sites. To put the GeoVT project in context, an overview of applications of VR in geosciences is provided. This paper subsequently proceeds with a presentation of the project and the GeoVT Authoring application, which is an innovative platform designed to help teachers and students, followed by brief presentations of a number of VFTs developed within the project. They address themes such as fluvial landforms and valley development, coastal landforms, evidence of past glaciation, coastal erosion, wildfire effects, mud volcanoes, and landslides.
The Kastrouli Late Bronze settlement in Phocis province, central Greece, has been proved to have been an important center in the periphery of the Mycenaean palaces. It was reused at least partially ...and was cultivated until the 20th century. The presence of a flat area off the Kastrouli hill and the seasonal flooding nowadays led to the present investigation, questioning the formation of an ancient lake or marsh/swamp. A methodological approach was applied combining the digital elevation model (DEM) and GIS of the wider and confined area, examining slopes between 0 and 5 degrees (0 and 8.75%), with electrical resistivity tomography (ERT) traverses of around 300 and 500 m, reaching a depth of 100 m. The ERT data were rapidly collected on profiles and provided a cross-sectional (2D) plot. It was found that, in the area, there is a basin with a length of 100 m and a depth of around 40–50 m. The sedimentation process over the millennia has filled the basin, with the upper 5–6 m surface layers of the area having a low resistivity. The presence of two natural sinkholes with apparent engineered hydraulic works is noted to conform to drainage and produce a habitable environment, protecting the cultivated land and avoiding a swamp associated with health issues.
This research applies the fuzzy set theory via Geographical Information Systems (GIS) – based analysis, in order to model slope erosion by runoff. For this purpose, the following steps were ...accomplished: definition of input variables (rocks’ susceptibility to erosion, slope inclination, slope morphology), development of a fuzzy inference system based on theoretical and empirical knowledge, transformation of input to output variables (erosion – deposition) and visualization of the output variables (spatial distribution of erosion–deposition processes). The method was applied on the drainage basin of Corinth, located in the north–eastern part of Peloponnese (Greece), where a series of catastrophic erosional events have recently occurred.
In this paper we attempt to classify drainage sub-basins according to their erosion risk. We have adopted a multistep procedure to face this problem. The input variables were introduced into a GIS – ...platform. These variables were the vulnerability of the surface rocks to erosion, topographic variations, vegetation cover, land use and drainage basin characteristics. We constructed a fuzzy inference mechanism to pre-process the input variables. Next we used neural–network technology to process the input variables. The system was trained to ‘learn’ and classify the input data. The output of this procedure was a classification of the sub-drainage basins related to their risk of erosion. This neuro–fuzzy system was applied to the island of Lefkas (Greece).
There is a wide range of alternative approaches to study erosion processes. In this paper, we describe the construction of a model based on the interaction of Geographical Information System (GIS) ...and Artificial Neural Networks (ANN). The neural model uses supervised competitive learning process. The whole process begins with the digitization of collected data and the definition of the input variables, such as slope form and gradient, susceptibility to erosion and protective cover. The input variables are transformed into the erosion risk output variable using the neural model. The last stage is the development of a map of erosion risk zones. As a case study the island of Corfu (Ionian Sea, Greece) was chosen, which consists of lithologies very vulnerable to erosion and receives considerable amounts of rainfall, especially in comparison to the rest of Greece. Finally, the whole model was validated and its proper function was confirmed by field data observations.
Biophysical restoration or rehabilitation measures of land have demonstrated to be effective in many scientific projects and small-scale environmental experiments. However circumstances such as ...poverty, weak policies, or inefficient scientific knowledge transmission can hinder the effective upscaling of land restoration and the long term maintenance of proven sustainable use of soil and water. This may be especially worrisome in lands with harsh environmental conditions. This review covers recent efforts in landscape restoration and rehabilitation with a functional perspective aiming to simultaneously achieve ecosystem sustainability, economic efficiency, and social wellbeing. Water management and rehabilitation of ecosystem services in croplands, rangelands, forests, and coastlands are reviewed. The joint analysis of such diverse ecosystems provides a wide perspective to determine: (i) multifaceted impacts on biophysical and socio-economic factors; and (ii) elements influencing effective upscaling of sustainable land management practices. One conclusion can be highlighted: voluntary adoption is based on different pillars, i.e. external material and economic support, and spread of success information at the local scale to demonstrate the multidimensional benefits of sustainable land management. For the successful upscaling of land management, more attention must be paid to the social system from the first involvement stage, up to the long term maintenance.
Degradation of coastal environments is an issue that many areas in Europe are facing. In the present work, an ancient coastal lake wetland is investigated, the so-called Lake Lerna in NE Peloponnese, ...Greece. The area hosted early agricultural populations of modern Greece that started modifying their environment as early as the early–middle Neolithic. Two drill cores in the area of the ancient lake were analysed to establish the sedimentological succession and the depositional environments using sub-fossil assemblages (molluscs and ostracods). Three lithological and faunal units were recovered, the latter being confirmed by the statistical ordination method (non-metric multidimensional scaling). The usage of sub-fossil mollusc species for the first time in the region enriched the dataset and contributed significantly to the delimitation of the faunas. These consist of environments characterised by various levels of humidity (from stagnant waters to freshwater lake) and salinity, with ephemeral intrusions of salt water to the lake, documented by mollusc and ostracod populations. We conclude that the lake and its included fauna and flora were mostly affected by climatic fluctuations rather than human intervention in the area.
This is a highly descriptive textbook providing an excellent introduction to the latest methodologies for mapping geomorphological formations in a variety of environments. Case studies with many ...examples of geomorphological maps are included.
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