Σκοπός της εργασίας είναι η καταγραφή των κατολισθήσεων στο φαράγγι του Βουραϊκού ποταμού και η ανάπτυξη βάσης δεδομένων κατολισθήσεων. Η περιοχή του Βουραϊκού αποτελεί εθνικό πάρκο, καθώς έχει μεγάλη γεωλογική, βιολογική, αισθητική, γεωμορφολογική και οικοτουριστική αξία. Η αναγνώριση και καταγραφή των κατολισθήσεων έγινε με την εφαρμογή του Google Earth, την εφαρμογή απεικόνισης δορυφορικών εικόνων υποβάθρου της Κτηματολόγιο Α.Ε. και του γεωγραφικού συστήματος πληροφοριών ArcGIS. / The purpose of this work is to record landslides in the canyon of Vouraikos and to develope a landslide database. The area of Vouraikos is a national park, as it has great geological, biological, aesthetic, geomorphological and ecotourism value. The identification and registration of landslides was done with the implementation of Google Earth, the satellite imaging application background image of Cadastre SA and the geographic information system ArcGIS.

Volcanoes are dynamic evolving structures, with life cycles that are punctuated by episodes of flank instability. Putauaki (Mount Edgecumbe) is a stratovolcano located onshore in the Bay of Plenty, New Zealand. The aim of this study was to assess the stability of Putauaki and analyse the risk associated with volcanic collapse. To achieve this objective, a multidisciplinary approach was used, incorporating geomorphological and geological mapping, rock mass classification, laboratory testing to identify geotechnical properties of materials representative of the volcano, stability modelling, and analysis of landslide run-out zones. Putauaki comprises two predominant features including the larger and younger Main Cone (the summit lying 820 m a.s.l., slope angles up to 36 ), and smaller and older Main Dome (the summit lying 420 m a.s.l., slope angle of 24 ). Both features show little evidence of erosion or surface water. Rock mass description defined six lithotechnical units including indurated andesite, indurated dacite, scoriaceous andesite, altered andesite (all categorised as hard rocks), and block and ash flow and Matahina Ignimbrite (both categorised as soft rocks). The uniaxial compressive strength (UCS) of indurated andesite and indurated dacite was 60 4 MPa and 44.7 0.9 MPa respectively, correlating with moderately strong rock. Discontinuities of the indurated units were widely spaced, showed medium persistence and wide aperture, and were slightly weathered. Infill comprised predominantly loosely packed, very strong, coarse gravel. UCS of scoriaceous andesite and altered andesite was 25 5 MPa and 15 1 MPa respectively, allowing categorisation as very weak rock. Discontinuities of scoriaceous andesite were widely spaced, showed high persistence and wide aperture, and were moderately weathered. Discontinuities of the altered andesite were moderately spaced, showed low persistence and wide aperture, and were highly weathered. Infill of scoriaceous and altered andesite was loosely packed, moist, weak to very weak medium gravel. The block and ash flow was a poorly sorted, loosely packed, sandy, gravely and cobble rich matrix supported deposit. The Matahina Ignimbrite was a very weak, discontinuity-poor deposit. Shear box testing indicated cohesion and friction angle of 0 MPa and 42.1 (block and ash flow) and 1.4 x 10-3 MPa and 41.7 (Matahina Ignimbrite) respectively. These values are similar to published values. Correlation of each lithotechnical unit to its respective rock mass description site allowed approximate boundaries of each unit to be mapped. Each unit's mass strength was combined with measured bulk densities and incorporated into two dimensional slope profiles using the stability modelling package GalenaTM. Ten slope profiles of Putauaki were constructed. Failure surfaces for each slope profile were defined using the Bishop simplified multiple analysis method. Four slope profiles showed the potential for small scale failure (less than 0.1 km2 of material). The remaining six slope profiles showed the potential for large scale failure (greater than 0.1 km2 of material). Stability of these six slope profiles was investigated further in relation to earthquake force, watertable elevation, and a disturbance factor of the rock mass (D). Conditions of failure graphs for profile 6a showed that at low D (less than 0.4), earthquake forces and watertable elevation must be unrealistically high for the region (greater than 0.33 g; greater than 15% watertable elevation) in order produce a factor of safety less than 1. The remaining five slope profiles showed potential to be unstable under realistic earthquake forces and watertable elevations. Two of these profiles were unable to achieve stability at D greater than 0.8 (profile 4) and D greater than 0.9 (profile 5). A D value of 0.6 (intermediate between 0.4 and 0.8) is argued to most realistically represent Putauaki. The fact that Putauaki has not undergone large scale failure to date supports the conclusion that the constructed models overestimate the influence of those factors which promote slope instability. Maximum and minimum landslide run-out zones were constructed for the slope profiles exhibiting the potential for large scale failure. Definition of the position and extent of maximum and minimum run-out zones assumed H/L (fall height to run-out length) ratios of 0.09 and 0.18 respectively, as well as the 'credible flow path' concept. Identified impacts of landslides sourced from Putauaki include inundation of Kawerau Township, Tarawera River, forestry operations, road networks, and power supplies. Based on these impacts, the risk posed by landslides from each slope profile was categorised as ranging from relatively low to relatively high. Landslides sourced from the south-west flanks pose a relatively low risk due to their prerequisite of unrealistically high watertable elevations and earthquake forces. Landslides sourced from the north-west flanks pose a relatively high risk as minimum run-out will inundate north-east parts of Kawerau Township. Landslides sourced from the eastern flanks pose a moderate risk due to their run-out zones avoiding Kawerau Township.

Thesis (M. Sc.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (M.S.)--Oregon State University, 2003. / Typescript (photocopy). Includes bibliographical references (leaves 99-101). Also available on the World Wide Web.

Thesis (M.S.)--Brigham Young University. Dept. of Geology, 2003. / Includes bibliographical references (p. 38-40).

published_or_final_version / Applied Geosciences / Master / Master of Science

published_or_final_version / toc / Applied Geosciences / Master / Master of Science

Η περιοχή παρουσιάζει ιδιαίτερο ενδιαφέρον λόγω των συχνών κατολισθητικών φαινομένων. Σκοπός της εργασίας είναι η παρακολούθηση της κατολισθαίνουσας ζώνης της Παναγοπούλας βάση μετρήσεων που έχουν ληφθεί μέσα στο χρόνο και ο προσδιορισμός του ρυθμού μετακίνησης της περιοχής λόγω της κατολίσθησης. Τα συμπεράσματα που θα προκύψουν δίνουν μια εικόνα για την εξέλιξη της κατολισθαίνουσας ζώνης στο χρόνο, από τα οποία ίσως βγουν συμπεράσματα για την πορεία της στο μέλλον. Στο Κεφάλαιο 1 ακολουθεί μια περιγραφή της περιοχής μελέτης. Περιγράφεται η γεωγραφική θέση, το μορφολογικό ανάγλυφο, η υδρογεωλογία και η σεισμολογία της περιοχής . Επίσης, γίνεται αναφορά στην γεωλογική δομή και στις γεωλογικές συνθήκες καθώς και περιγραφή των γεωλογικών σχηματισμών που δομούν την περιοχή. Το Kεφάλαιο 2 αναφέρεται στα κατολισθητικά φαινόμενα της περιοχής μελέτης. Αρχικά γίνεται αναφορά στα διάφορα είδη κατολισθητικών κινήσεων (ονοματολογία, ταξινόμηση, αίτια μετακίνησης) και στην συνέχεια γίνεται λεπτομερής παρουσίαση του ιστορικού των κατολισθητικών φαινομένων στην περιοχή της Παναγοπούλας με τις συνεχείς επαναδραστηριοποιήσεις από τις αρχές της δεκαετίας του 1970 έως και σήμερα. Στο Kεφάλαιο 3 γίνεται αρχικά αναφορά στην περιγραφή και χρήση των αποκλισιομετρικών οργάνων γενικότερα, καθώς και παρουσίαση της μεθοδολογίας και λειτουργίας τους. Στην συνέχεια παρουσιάζονται – ερμηνεύονται τα αποτελέσματα των αποκλισιομετρικών μετρήσεων στην περιοχή. / The area is of particular interest because of frequent landslides. The aim of the study is to monitor the landslide zone of Panagopoula based on measurements taken over time while we try to determine the rate of travel in the region due to landslides. The conclusions drawn give an insight into the evolution of the landslide zone in time, which can give us approximate readings about the course of the future. Chapter 1 evolves around a description of the study area. Thus we give a territorial description of the geographic location, terrain morphology, hydrogeology and seismology of the area, also we refer to the geological structure, geological conditions and a description of the geological formations that populate the region. Chapter 2 refers to landslides in the study area. Originally referring to the different type of landslide movement (nomenclature, classification, causes movement) and then it gives out a detailed presentation of the history of the landslides in the Panagopoula region takin in account the continuous reactivation of the early 1970’s until today. Chapter 3 starts by referring to the description and use of the inclinometer in general, all in all the presentation of the methodology and operation of it, while at the same time we present – interpret and analyze the results of inclinometer measurements in the region.

No description available.