Fluvial landforms and processes in the region of the Aegean Sea, based on Ikaria Island (Greece)

Main aims of the research were: i) to assess the degree of development of fluvial landforms on Aegean Islands and ii) to determine the influence of fluvial processes on modification of islands relief. Field studies were conducted on the Ikaria Island, with highly diversified geology and relief, typical of mountainous islands of the Aegean Sea. The island is heavily dissected by deeply incised valleys and gorges with very steep slopes. The valleys on Ikaria Island vary in size, direction, geological setting and maturity. In the four small catchments located in the northern part of the Ikaria Island four types of valleys (from 1st to 4th order, according to Strahler) were studies in detail. Uppermost parts of these valleys (1st order valleys) have slightly concave cross-sections covered with regolith without developed channels. Such forms gradually evolve into 2nd order valleys with seasonal river channels, and further downstream, into well developed deep river valleys. Ravines with channels incised into solid rock are characteristic of the 3rd order valleys. The 4th order valleys are well developed, deeply incised gorges with wide channels sometimes accompanied by river terraces. Channels of small streams, rivers and field tracks in the mountains are subject to differentiated modelling by running water. In islands of the Aegean Sea, intensity of this modelling is diversified and rather small. It depends mostly on rainfall intensity, bedrock resistance to erosion, slope inclination and aspect. Catastrophic hydrometeorological events such as one which occurred in Ikaria in October, 2010, are responsible for rapid modification of whole valley floors and modification of river channels at lower river runs, within deltas and alluvial fans

Anthropogenic transformation of the relief of the Aegean Islands

The purpose of this article is to present the role of human impact in the forming and transformation of the relief of the Aegean Islands. The most significant changes (with a displacement of more than 10 bln m3 of rock material) are related to the creation of road infrastructure and the construction of agricultural terraces. In order to create stone buildings, 20 mln m3 of rock material was used; for the purposes of air transport a surface area of nearly 2.5 km2 was levelled; many kilometres of artificial shorelines were created and at least 4.5 mln m3 of material was displaced for the purposes of the construction of artificial reservoirs of a total capacity of more than 25 mln m3. A huge amount of material was removed as a result of mining activities. The indirect impact of economic activities on the relief of the discussed area includes mainly slope, fluvial and coastal processes

Effects of human impact on the beds of minor watercourses of the Aegean Island of Icaria (Greece)

The aim of the work was to show the scale of changes of riverbeds in the conditions of Mediterranean climate and many ages of human impact, on the example of Icaria, an island situated in the eastern part of the Aegean Sea. The most altered riverbed fragments were selected and the main types of conversion were defined based on the terrain mapping and the interviews with the inhabitants. They are as follows: the increase in the seasonality of tides, the transformation of the riverbed fragments into paths, the narrowing of the riverbeds, the strengthening of their bottoms and banks, the partitioning of the riverbeds with the proprietary boundaries, the inclusion of the riverbeds into the irrigation system and the creation of infrastructure to be used by watermills. The riverbeds that were altered the most were the ones within villages, up to 400 m above sea level. Changes described were taking place in stages. In antiquity they concerned only the estuary parts. Until the 1950s they covered arable areas inside the island. After 1970 there followed a drastic diminishing of flows in the riverbeds and there appeared riverbeds with artificial bottoms

Morphogenetic processes in Greece as a threat to mankind

The purpose of this paper is to draw attention to the extent of the threat imminent in the contemporary dynamics of the relief in Greece.46547

Function of Agricultural Terraces in Mediterranean Conditions - Selected Examples From the Island of Ikaria (The Southern Sporades, Greece)

The aim of the research was to define the influence of agricultural terraces on slope erosion. There have been selected three plots located on the Greek island Ikaria. On the plots detailed geomorphological mapping was done, spatial relief models were created based on the measurements taken using GPS RTK, georadar profiles were made using RAMAC/GPR and the extent of destruction of terrace resistance walls was evaluated.In comparison with similar forms on other Aegean islands, Ikarian terraces are narrow and high. Their stability depends on: lihtology, slope gradient, height and spatial arrangement of particular terrace steps and the current way of their usage. It was acknowledged that the most stable are the forms created on crystalline schists and gneisses, whereas the slopes, which erode the easiest, are the terraced ones consisting of carbonate rocks.The obtained results indicate that on Ikaria similarly to numerous other regions the most significant factor facilitating erosion on the terraced slopes is the cessation of their agricultural usage

Function of Agricultural Terraces in Mediterranean Conditions - Selected Examples From the Island of Ikaria (The Southern Sporades, Greece)

The aim of the research was to define the influence of agricultural terraces on slope erosion. There have been selected three plots located on the Greek island Ikaria. On the plots detailed geomorphological mapping was done, spatial relief models were created based on the measurements taken using GPS RTK, georadar profiles were made using RAMAC/GPR and the extent of destruction of terrace resistance walls was evaluated.In comparison with similar forms on other Aegean islands, Ikarian terraces are narrow and high. Their stability depends on: lihtology, slope gradient, height and spatial arrangement of particular terrace steps and the current way of their usage. It was acknowledged that the most stable are the forms created on crystalline schists and gneisses, whereas the slopes, which erode the easiest, are the terraced ones consisting of carbonate rocks.The obtained results indicate that on Ikaria similarly to numerous other regions the most significant factor facilitating erosion on the terraced slopes is the cessation of their agricultural usage