Μελέτη της παράκτιας τρωτότητας της νήσου Ίου, Κυκλάδες

Η παρούσα διπλωματική εργασία αποσκοπεί στην εκτίμηση της παράκτιας τρωτότητας των ακτών της νήσου Ίου, Κυκλάδες και την αναγνώριση περιοχών που είναι συγκριτικά περισσότερο ευάλωτες στις μεταβολές της θαλάσσιας στάθμης. Από την εφαρμογή του Δείκτη Παράκτιας Τρωτότητας (C.V.I), το 92,37% του συνολικού μήκους της ακτογραμμής της Ίου χαρακτηρίζεται από πολύ χαμηλή τρωτότητα καθώς αποτελείται από βραχώδεις ακτές και κρημνούς με κλίση πάνω από 12%. Το μικρότερο ποσοστό του συνόλου της ακτογραμμής αντιστοιχεί σε 1,72 km, χαρακτηρίζεται από πολύ υψηλή τρωτότητα και αντιπροσωπεύεται από αμμώδεις παραλίες και pocket beaches. Σε αυτή την κατηγορία ανήκουν οι παραλίες Μυλοπότας και Μαγγανάρι για τις οποίες μελετήθηκαν τα ιζηματολογικά και μορφολογικά χαρακτηριστικά τους καθώς και η μετατόπιση της ακτογραμμής τους σε εποχική κλίμακα, μεταξύ εαρινής και φθινοπωρινής περιόδου μελέτης. Από την τοπογραφική αποτύπωση που πραγματοποιήθηκε κατά τις εργασίες υπαίθρου με τη χρήση DGPS-RTK, προκύπτει πως η παραλία του Μυλοπότα χαρακτηρίζεται από ομαλοποίηση του ανάγλυφου του πυθμένα, ενώ το Μαγγανάρι χαρακτηρίζεται κυρίως από ρήχωση του πυθμένα προς τη φθινοπωρινή περίοδο μελέτης. Από την εφαρμογή της μεθόδου του ξηρού κοσκινίσματος στα δείγματα άμμου που συλλέχθηκαν κατά τις εργασίες υπαίθρου, προκύπτει πως και στις δύο παραλίες επικρατεί η ελαφρώς χαλικώδης άμμος σε εποχική κλίμακα. Για τον υπολογισμό της εποχικής μεταβολής της ακτογραμμής στον Μυλοπότα και το Μαγγανάρι, χρησιμοποιήθηκαν οι μετρήσεις κατά μήκος της δεδομένης θέσης της ακτογραμμής από τις εργασίες πεδίου. Με τη χρήση του εργαλείου DSAS, προκύπτει οπισθοχώρηση της ακτογραμμής, από την εαρινή προς τη φθινοπωρινή περίοδο στο βόρειο και νότιο τμήμα του Μυλοπότα μεταξύ 2-5 m, ενώ το κεντρικό τμήμα είναι σχεδόν σταθερό. Στο Μαγγανάρι επικρατεί προέλαση της φθινοπωρινής ακτογραμμής σε σχέση με την εαρινή έως 5 m στο ανατολικό τμήμα, ενώ το δυτικό χαρακτηρίζεται από σταθερή ακτογραμμή.The present dissertation aims to assess the coastal vulnerability of the coasts of Ios Island, Cyclades and to identify areas that are comparatively more vulnerable to sea level change. From the application of Coastal Vulnerability Index, 92,37% of the total length of the coastline of Ios Island is characterized by very low vulnerability as it consists of rocky shores and cliffs with a slope of over 12%. The smallest percentage of the entire coastline corresponds to 1,72 km, is characterized by very high vulnerability and is represented by sandy and pocket beaches. The coastal areas of Mylopotas and Magganari belong to the above category. Their sedimentological and morphological characteristics were studied as well as shoreline changes on a seasonal scale, between spring and autumn study period. From the topographic survey carried out during fieldworks, using DGPS-RTK, it appears that Mylopotas beach is characterized by gently seabed’s topography towards the autumn study period, while Magganari is mainly characterized by shallowness of the bottom towards the autumn study period. From the application of dry granulometry method to the sand samples collected during the field work, it appears that on both sites, slightly gravelly sand prevails on a seasonal scale. To calculate the seasonal shoreline changes in Mylopotas and Magganari, the measurements from the field work along the current position of the shoreline were used. The calculation of the seasonal shoreline displacement, using the DSAS tool, results in a retreat of the shoreline, from spring to autumn study period, in the northern and southern part of Mylopotas between 2-5 m, while the central part is almost stable. In Magganari, there is an accretion of the autumn shoreline in relation to the spring shoreline of up to 5 m in the eastern part, while the western part is characterized by a stable shoreline

Coastal Vulnerability Assessment for Future Sea Level Rise and a Comparative Study of Two Pocket Beaches in Seasonal Scale, Ios Island, Cyclades, Greece

The coastal zone may be considered as the location where the marine and land environments interact dynamically and coexist with human societies. Globally, natural and human systems are being severely threatened by the sea level rise related to climate change. The outcome between the dynamic relationship of coastal environments and marine processes, and the future sea level rise as predicted by scientific reports, is the vulnerability of coastal areas such as sandy beaches, pocket beaches and low-lying coastal areas. The current research aims to assess the coastal vulnerability of Ios Island, Cyclades, Greece for the next 100 years and to identify areas that are comparatively more vulnerable to future sea level changes. Moreover, the seasonal changes concerning sedimentological and morphological characteristics of two pocket beaches of Ios Island, Mylopotas and Magganari, are also examined. From the application of the Coastal Vulnerability Index, 92.37% of the total length of the coastline of Ios Island is characterized by a very low vulnerability as it consists of rocky shores and cliffs, while sandy and pocket beaches are characterized by a very high vulnerability. From the fieldworks and data processing, the seasonal changes mainly concern the seabed’s topography, the sediments’ texture of the collected sand samples, the foreshore and backshore topography, as well as seasonal shoreline displacement, using the Digital Shoreline Analysis System tool (DSAS)

Coastal Vulnerability Assessment for Future Sea Level Rise and a Comparative Study of Two Pocket Beaches in Seasonal Scale, Ios Island, Cyclades, Greece

The coastal zone may be considered as the location where the marine and land environments interact dynamically and coexist with human societies. Globally, natural and human systems are being severely threatened by the sea level rise related to climate change. The outcome between the dynamic relationship of coastal environments and marine processes, and the future sea level rise as predicted by scientific reports, is the vulnerability of coastal areas such as sandy beaches, pocket beaches and low-lying coastal areas. The current research aims to assess the coastal vulnerability of Ios Island, Cyclades, Greece for the next 100 years and to identify areas that are comparatively more vulnerable to future sea level changes. Moreover, the seasonal changes concerning sedimentological and morphological characteristics of two pocket beaches of Ios Island, Mylopotas and Magganari, are also examined. From the application of the Coastal Vulnerability Index, 92.37% of the total length of the coastline of Ios Island is characterized by a very low vulnerability as it consists of rocky shores and cliffs, while sandy and pocket beaches are characterized by a very high vulnerability. From the fieldworks and data processing, the seasonal changes mainly concern the seabed’s topography, the sediments’ texture of the collected sand samples, the foreshore and backshore topography, as well as seasonal shoreline displacement, using the Digital Shoreline Analysis System tool (DSAS)

GIS-Based Virtual Field Trip as a Tool for Remote Education

Geoscience courses, such as geology and geomorphology, require not only classroom lessons and laboratory exercises, but field trips as well. However, the COVID-19 restrictions did not allow the execution of most planned field trips, and an alternative needed to be developed. The use of virtual field trips is one such alternative. Through this research, we evaluate the usefulness of virtual field trips as tools for preparatory activities before an actual field trip takes place in the same area, and their contribution in providing a better understanding of geomorphological processes and landscape evolution. We performed a virtual navigation on the island of Naxos, Cyclades (Aegean Sea, Greece) for a series of virtual field trips, which took place during webinars in the framework of Erasmus+ CIVIS. The virtual field trip was also presented to the third-year students of the Faculty of Geology and Geoenvironment, National and Kapodistrian University of Athens, in the framework of the obligatory course of Geomorphology. Upon completion, all participating students were asked to fill in a questionnaire in order to evaluate the contribution of virtual field trips to their education regarding geomorphology and state their opinion as to whether they can supplement and/or substitute actual field trips. According to the results, virtual field trips can aid, but not substitute, the actual field trip. Most students mentioned that they would attend another virtual field trip in the future, both as an alternative to classroom lessons and as a means of preparation for an actual field trip, but not in order replace the actual one. Virtual field trips can significantly support the realization of actual ones, by introducing the necessary tectonic, geological and geomorphological background of a particular study area and offering more time for practical activities or field methodologies during the actual field trip

GIS-Based Virtual Field Trip as a Tool for Remote Education

Geoscience courses, such as geology and geomorphology, require not only classroom lessons and laboratory exercises, but field trips as well. However, the COVID-19 restrictions did not allow the execution of most planned field trips, and an alternative needed to be developed. The use of virtual field trips is one such alternative. Through this research, we evaluate the usefulness of virtual field trips as tools for preparatory activities before an actual field trip takes place in the same area, and their contribution in providing a better understanding of geomorphological processes and landscape evolution. We performed a virtual navigation on the island of Naxos, Cyclades (Aegean Sea, Greece) for a series of virtual field trips, which took place during webinars in the framework of Erasmus+ CIVIS. The virtual field trip was also presented to the third-year students of the Faculty of Geology and Geoenvironment, National and Kapodistrian University of Athens, in the framework of the obligatory course of Geomorphology. Upon completion, all participating students were asked to fill in a questionnaire in order to evaluate the contribution of virtual field trips to their education regarding geomorphology and state their opinion as to whether they can supplement and/or substitute actual field trips. According to the results, virtual field trips can aid, but not substitute, the actual field trip. Most students mentioned that they would attend another virtual field trip in the future, both as an alternative to classroom lessons and as a means of preparation for an actual field trip, but not in order replace the actual one. Virtual field trips can significantly support the realization of actual ones, by introducing the necessary tectonic, geological and geomorphological background of a particular study area and offering more time for practical activities or field methodologies during the actual field trip