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Modelling Losses in Flood EstimationIlahee, Mahbub January 2005 (has links)
Flood estimation is often required in hydrologic design and has important economic significance. For example, in Australia, the annual spending on infrastructure requiring flood estimation is of the order of $650 million ARR (I.E. Aust., 1998). Rainfall-based flood estimation techniques are most commonly adopted in practice. These require several inputs to convert design rainfalls to design floods. Of all the inputs, loss is an important one and defined as the amount of precipitation that does not appear as direct runoff. The concept of loss includes moisture intercepted by vegetation, infiltration into the soil, retention on the surface, evaporation and loss through the streambed and banks. As these loss components are dependent on topography, soils, vegetation and climate, the loss exhibits a high degree of temporal and spatial variability during the rainfall event. In design flood estimation, the simplified lumped conceptual loss models were used because of their simplicity and ability to approximate catchment runoff behaviour. In Australia, the most commonly adopted conceptual loss model is the initial losscontinuing loss model. For a specific part of the catchment, the initial loss occurs prior to the commencement of surface runoff, and can be considered to be composed of the interception loss, depression storage and infiltration that occur before the soil surface saturates. ARR (I. E. Aust., 1998) mentioned that the continuing loss is the average rate of loss throughout the remainder of the storm. At present, there is inadequate information on design losses in most parts of Australia and this is one of the greatest weaknesses in Australian flood hydrology. Currently recommended design losses are not compatible with design rainfall information in Australian Rainfall and Runoff. Also design losses for observed storms show a wide variability and it is always difficult to select an appropriate value of loss from this wide range for a particular application. Despite the wide variability of loss values, in the widely used Design Event Approach, a single value of initial and continuing losses is adopted. Because of the non-linearity in the rainfall-runoff process, this is likely to introduce a high degree of uncertainty and possible bias in the resulting flood estimates. In contrast, the Joint Probability Approach can consider probability-distributed losses in flood estimation. In ARR (I. E. Aust., 1998) it is recommended to use a constant continuing loss value in rainfall events. In this research it was observed that the continuing loss values in the rainfall events were not constant, rather than it decays with the duration of the rainfall event. The derived loss values from the 969 rainfall and streamflow events of Queensland catchments would provide better flood estimation than the recommended design loss values in ARR (I. E. Aust., 1998). In this research, both the initial and continuing losses were computed using IL-CL loss model and a single median loss value was used to estimate flood using Design Event Approach. Again both the initial and continuing losses were considered to be random variables and their probability distribution functions were determined. Hence, the research showed that the probability distributed loss values can be used for Queensland catchments in near future for better flood estimate. The research hypothesis tested was whether the new loss value for Queensland catchments provides significant improvement in design flood estimation. A total of 48 catchments, 82 pluviograph stations and 24 daily rainfall stations were selected from all over Queensland to test the research hypothesis. The research improved the recommended design loss values that will result in more precise design flood estimates. This will ultimately save millions of dollars in the construction of hydraulic infrastructures.
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Older adults' experiences of a flood disaster : making sense of an extraordinary event : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University, Palmerston North, New ZealandTuohy, Robyn Jean January 2009 (has links)
Disasters occur within the routines of everyday life and have a disruptive and destructive impact on human lives. To understand how older individuals make sense of a disaster, nine older adults in Kaitaia, New Zealand were interviewed about their experience of a flood they experienced in July 2007. These interviews were conducted with four residents living in a rest home and five pensioners living independently who were evacuated from their homes. The two groups differed in the levels of support and assistance received before, during, and after the disaster. The rest home residents experienced little disruption and did not require relocation; the pensioners experienced major disruption and relocation. Thematic analysis was used to describe how these older adults’ accounted for their experiences of the flood. The narratives were influenced by the participants’ identity as either dependent rest home residents or pensioners living independently in the community. The analysis revealed that their accounts of the disaster were incorporated and integrated into the personal and social context of each person’s life story. Narrative themes that emerged from the analysis for the pensioner group were: coping with limited assistance, the importance of treasured possessions, and social support and community. The pensioner themes reflected their vulnerability to a disaster and the challenges they faced during the post disaster recovery phase. Themes for the rest home residents were ageing and dependency, and the importance of protection, care, and trust. These themes reflected the dependent world of the rest home residents and the security of being cared for.
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Οι απαρχές της ελληνικής γεωμυθολογίας μέσα από τις κοσμογονίες, τις θεογονίες και τον κύκλο του ΗρακλήΜητροπέτρου, Ελένη 04 February 2014 (has links)
Σκοπός της διατριβής είναι να αποδειχθεί εάν οι μύθοι, οι οποίοι αναφέρονται σε δραστηριότητες θεών, ημιθέων, του Ηρακλή, αλλά και σε κατακλυσμούς και άλλα φυσικά φαινόμενα, έχουν πυρήνες αλήθειας ή όχι.
Η αντιδιαστολή μύθου και πραγματικότητας που γίνεται από πολλούς, είναι λανθασμένη, διότι βασίζεται στην ψευδή αντίληψη ότι όλοι οι μύθοι είναι πλαστοί. Οι παραδοσιακοί όμως μύθοι είναι γνήσιοι και αυτό συνεπάγεται ότι περιέχουν στον πυρήνα τους αληθινά γεγονότα, γεωλογικού, αστρονομικού και ιστορικού περιεχομένου, που προσφέρονται για διεπιστημονική έρευνα.
Οι πυρήνες των μύθων μπορούν να αποδειχθούν διεπιστημονικά, εφόσον έχουν σχέση με τις θετικές επιστήμες. Οι μύθοι είναι πνευματικά και πολιτισμικά παλίμψηστα, που φέρουν τα σημάδια της ιστορίας τους, δηλαδή των πολλαπλών επιπέδων χρήσης και αποκρυστάλλωσής τους.
Κατ’ αρχάς, παρατίθενται οι ορισμοί αρχαίων συγγραφέων για την μυθολογία. Ενδεικτικά παρατίθενται δύο από αυτούς.
α. Κατά τον Πλάτωνα (Κριτίας, 109 e 1 – 110 a 6), μυθολογία, δηλαδή λογική ερμηνεία των μύθων, είναι η πολύ προσεκτική και συστηματική έρευνα και αναζήτηση των παλαιών γεγονότων.
β. Κατά τον Πλούταρχο τον Χαιρωνέα (Περί των εν Πλαταιαίς Δαιδάλων, απ. 157, 16 – 21), η παλαιά φυσική επιστήμη ήταν φυσικός λόγος κρυμμένος βαθειά μέσα σε μύθους. Σύμφωνα λοιπόν με τον Πλούταρχο, οι γνήσιοι μύθοι είναι επιστημονικοί λόγοι, κρυμμένοι βαθειά μέσα σε μυθικά περιτυλίγματα, που διατυπώνονται με αινιγματικά λόγια και υπονοούμενα.
Στο επόμενο κεφάλαιο, που πραγματεύεται την ερμηνεία των μύθων, επισημαίνονται οι αρχές, που είναι χρήσιμες και αναγκαίες, για να διεισδύσει κάποιος στους πυρήνες αλήθειας των μύθων.
Ακολούθως προσεγγίζεται η γεωμυθολογία και εξηγείται η ουσία της. Συγκεκριμένα, ο όρος «γεωμυθολογία», επινοήθηκε από την Αμερικανίδα γεωλόγο και ηφαιστειολόγο Dorothy Vitaliano. Σύμφωνα με αυτήν, γεωμυθολογία είναι η διεπιστημονική ανάλυση των γνησίων μύθων, η οποία οδηγεί στον εντοπισμό των γεωφυσικών και ενδεχομένως και άλλων συμβάντων, αστρονομικών ή και ιστορικών, που υποκρύπτονται σε αυτούς. Μερικές φορές αυτή η ανάλυση προσφέρει πολύτιμες πληροφορίες και γνώσεις για κατακλυσμούς, που διασώζονται με μυθικό περίβλημα στις παραδόσεις των λαών, αλλά και για άγνωστους κατά τα άλλα αρχαίους σεισμούς, θαλάσσιους ή λιμναίους σεισμικούς κυματοσυρμούς, τεχνικά έργα, καθώς και άγνωστα αστρονομικά φαινόμενα (διελεύσεις κομητών, εκλείψεις, πτώσεις μετεωριτών, αλλαγές του βορείου πόλου της ουράνιας σφαίρας, συσχετισμούς αστερισμών με συγκεκριμένους ήρωες κλπ.), που συνέβησαν στο απώτερο παρελθόν.
Στη συνέχεια, διερευνώνται οι τρεις κατακλυσμοί της ελληνικής παράδοσης, οι άθλοι και τα έργα του Ηρακλή, που έχουν γεωμυθολογικό ενδιαφέρον, και προτείνονται ταυτοχρόνως συγκεκριμένα περαιτέρω ερευνητικά πεδία για καλύτερη τεκμηρίωσή τους.
Τέλος, διερευνάται η ώσμωση των πολιτισμών της ανατολικής Μεσογείου και δίνεται απάντηση στο ερώτημα, εάν η ελληνική μυθολογία απηχεί γεωλογικές και κλιματολογικές μεταβολές, που συνέβησαν μάλλον στην ευρύτερο χώρο του Αιγαίου ή σε άλλες περιοχές του κόσμου.
Στο κεφάλαιο, που πραγματεύεται την ερμηνεία των μύθων, επισημαίνονται οι αρχές, που είναι χρήσιμες και αναγκαίες, για να διεισδύσει κάποιος στους πυρήνες αλήθειας των μύθων.
Όμως, για να γίνει με σωστό τρόπο η ερμηνεία των γεωλογικής και αστρονομικής υφής μύθων, απαιτούνται ολοκληρωμένες γνώσεις στα πεδία της γεωλογίας, της αστρονομίας, της αρχαιολογίας, της φιλολογίας, της ιστορίας, της συγκριτικής μυθολογίας και της ανθρωπολογίας. Η γεωλογική, αστρονομική και εν γένει επιστημονική μελέτη της μυθολογίας μπορεί να αποκαλύψει κωδικοποιημένες μνήμες γεωλογικών και αστρονομικών συμβάντων του παρελθόντος, παρέχοντας έτσι μία δεξαμενή επιστημονικών δεδομένων. Από την άλλη μεριά συντελεί επίσης στο να δώσει μία νέα οπτική γωνία στην ιστορική, την αρχαιολογική και την ανθρωπολογική έρευνα, ανοίγοντας παράθυρα σε πεδία γνώσεων, που φωτίζουν την πρώιμη σύλληψη του κόσμου και βελτιώνουν την αυτογνωσία του ανθρώπου.
Εν συνεχεία, η εργασία πραγματεύεται τους τρεις κατακλυσμούς της ελληνικής παράδοσης, που προσφέρονται για γεωμυθολογική έρευνα.
Συγκεκριμένα, για τον κατακλυσμό του Δαρδάνου γράφει μεταξύ άλλων ο Διόδωρος Σικελιώτης: «Ο κατακλυσμός αυτός έγινε επειδή κατ’ αρχήν άνοιξε το στόμιο γύρω από τις Κυάνεες πέτρες, εκεί που τοποθετούνται οι Συμπληγάδες πέτρες (η θέση τους βρισκόταν κατά πάσα πιθανότητα στην έξοδο των στενών του Βοσπόρου προς τον Εύξεινο Πόντο). Στη συνέχεια άνοιξε το στόμιο του Ελλησπόντου. Αυτό συνέβη επειδή η Θάλασσα του Πόντου, δηλαδή ο υδάτινος όγκος του πόντου, που μέχρι τότε ήταν λίμνη, γέμισε από τα νερά των ποταμών που χύνονται σε αυτήν, με αποτέλεσμα να ανέβει η στάθμη της τόσο πολύ, ώστε να υπερχειλίσει τα στενά του Βοσπόρου, να γεμίσει την Προποντίδα και κατόπιν, αφού υπερχείλισε και το Στενό του Ελλησπόντου, να ξεσπάσει στο Αιγαίο. Το αποτέλεσμα ήταν να κατακλυστεί μεγάλη παραθαλάσσια περιοχή, όχι μόνον της Ασίας αλλά και της Σαμοθράκης».
Σύμφωνα με την έρευνα, που διεξήχθη, ο κατακλυσμός του Δαρδάνου έγινε σε δύο φάσεις: μία κατά την οποία τα νερά του υδάτινου όγκου του Ευξείνου Πόντου χύθηκαν στο Αιγαίο (μεταξύ των ετών 14500 και 12500 Π.Α.Σ.) και μία κατά την οποία τα νερά του Αιγαίου πελάγους, μετά τη διάνοιξη του στενού του Βοσπόρου, χύθηκαν υπό μορφή μεγάλου καταρράκτη στην Μαύρη Θάλασσα περί το έτος 7600 Π.Α.Σ. (5600 π.Χ.). Κατά πάσα πιθανότητα η δεύτερη φάση αυτού του κατακλυσμού έδωσε το έναυσμα της δημιουργίας των μύθων των κατακλυσμών του Atrahasis, του Ziusudra, του Utnapistim και του Νώε. Οι δύο αυτές φάσεις του κατακλυσμού του Δαρδάνου χρειάζονται ωστόσο περαιτέρω συστηματικές γεωλογικές, γεωφυσικές και ενάλιες αρχαιολογικές έρευνες, για να τεκμηριωθούν πλήρως.
Ως προς τον κατακλυσμό του Ωγύγου, ο Ελλάνικος γράφει ότι αυτός έγινε χίλια είκοσι έτη πριν από την πρώτη Ολυμπιάδα. Δεδομένου δε ότι η πρώτη Ολυμπιάδα τοποθετείται στο έτος 776 π.Χ., συνάγεται ότι ο κατακλυσμός αυτός έγινε το έτος 1796 π.Χ. Η συσχέτιση όμως του Ωγύγου με τον Κρόνο, τους Τιτάνες και τα γεωλογικά γεγονότα της Θεσσαλίας οδηγεί στο συμπέρασμα ότι ο ομώνυμος κατακλυσμός θα πρέπει μάλλον να έγινε σε πολύ παλιά εποχή και κατά πάσα πιθανότητα μεταξύ των ετών 14500 και 12500 Π.Α.Σ. Και αυτή όμως η εκδοχή χρήζει περαιτέρω γεωλογικής έρευνας, για να τεκμηριωθεί.
Τέλος, ο κατακλυσμός του Δευκαλίωνα έχει σχέση κυρίως με τρία διαφορετικά σημεία αναφοράς:
α. Με τον Κορινθιακό κόλπο. Η εκδοχή αυτή έχει πλήρως τεκμηριωθεί από τον Λυκούση και άλλους, σύμφωνα με τους οποίους ο κόλπος αυτός επανειλημμένως είχε μετατραπεί από λιμναία σε θαλάσσια λεκάνη και αντιστρόφως, κατά τη διάρκεια του ανώτερου Πλειστοκαίνου (126.000 – 10.000 Π.Α.Σ.), γεγονός που οφείλεται στην διακύμανση της στάθμης της παγκόσμιας θάλασσας και στο μικρό βάθος του στενού του Ρίου – Αντιρρίου.
Ο Κορινθιακός κόλπος παρέμεινε απομονωμένος από την Μεσόγειο θάλασσα μέχρι 13000 χρόνια Π.Α.Σ. Η τελευταία αυτή χρονολογία αποτελεί και το όριο των λιμναίων καθιζήσεων και της εγκατάστασης θαλασσίων συνθηκών σε αυτόν. Με την εισροή των θαλασσίων υδάτων στον κόλπο πλημμύρισαν οι παράκτιες περιοχές, μεταξύ των οποίων και η περιοχή της τότε Φωκίδας, με την οποία συσχετίζεται και ο κατακλυσμός του Δευκαλίωνα. Ο Δευκαλίων σώθηκε με την κατασκευή κάποιας σχεδίας, η οποία προσάραξε στον Παρνασσό. Κατά πάσα όμως πιθανότητα ο γεωγραφικός όρος «Παρνασσός» δεν αναφέρεται μόνον στο ομώνυμο όρος, αλλά σε μία ευρύτερη περιοχή, η οποία συμπεριλαμβάνει και το όρος.
β. Με την Θεσσαλία. Σχετικά με αυτή την εκδοχή, ο Απολλόδωρος γράφει ότι ο κατακλυσμός του Δευκαλίωνα έγινε όταν διαχωρίστηκαν τα όρη της Θεσσαλίας, γεγονός που συνέβη κατά πάσα πιθανότητα μεταξύ των ετών 14500 και 12500 Π.Α.Σ. Σε αυτήν την περίοδο έχει επισημανθεί σημαντικές κλιματολογικές και γεωλογικές αναστατώσεις σε όλον τον πλανήτη. Εάν γίνουν γεωτρήσεις στη Θεσσαλία, θα καταστεί δυνατόν να αποδειχθεί εάν πράγματι έγινε στην περιοχή αυτή ένας ή περισσότεροι κατακλυσμοί. Οι πυρήνες των γεωτρήσεων μπορούν να χρονολογηθούν.
Επίσης για τη σχέση του κατακλυσμού του Δευκαλίωνα με τη Θεσσαλία και τον Παρνασσό, ο Παύλος Ορόσιος, Λατίνος συγγραφέας του 5ου αιώνα μ.Χ., γράφει ότι ο κατακλυσμός αυτός έγινε το έτος 810 προ της κτίσεως της Ρώμης (που έγινε το έτος 753 π.Χ.), όταν βασιλιάς της Αθήνας ήταν ο Αμφικτύων, τρίτος μετά τον Κέκροπα. Κατά τους χρόνους της βασιλείας του, πλημμύρες υδάτων κατέκλυσαν το μεγαλύτερο μέρος των λαών της Θεσσαλίας και μόνο λίγοι σώθηκαν, καταφεύγοντας στα όρη και κυρίως στον Παρνασσό, στην περιοχή του οποίου βασίλευε τότε ο Δευκαλίων, ο οποίος, αφού παρέλαβε με πλοία όσους κατέφυγαν προς αυτόν, τους περιέθαλψε και τους έθρεψε στις δίδυμες κορυφές του Παρνασσού. Εξαιτίας αυτού του γεγονότος, διαδίδουν ότι από αυτόν ξαναδημιουργήθηκε το γένος των ανθρώπων.
Και αυτή όμως η εκδοχή χρειάζεται περαιτέρω επιστημονική διερεύνηση.
γ. Όμως το Πάριο χρονικό, χωρίς να συσχετίζει τον κατακλυσμό του Δευκαλίωνα με κάποια περιοχή, τον θεωρεί πολύ μεταγενέστερο. Συγκεκριμένα γράφει ότι ο κατακλυσμός του Δευκαλίωνα έγινε 1265 έτη πριν από τη συγγραφή του Χρονικού. Και δεδομένου ότι το Χρονικό αυτό συντάχθηκε το έτος 264 / 3 π.Χ., επί του Αθηναίου επωνύμου άρχοντος Διογνήτου, θα πρέπει να έγινε το έτος 1529 / 8 π.Χ. Υπάρχει όμως η πιθανότητα, ο κατακλυσμός που αναφέρεται στο Πάριο χρονικό, να είναι κάποιος μεταγενέστερος τοπικός κατακλυσμός της 2ης χιλιετίας π.Χ., που έχει διασωθεί με το ίδιο όνομα και που θα πρέπει να επιβεβαιωθεί με γεωλογικές έρευνες στην περιοχή της Αττικοβοιωτίας.
Καταλήγοντας, συνάγουμε το συμπέρασμα ότι και οι τρεις κατακλυσμοί της ελληνικής παράδοσης, του Δαρδάνου, του Ωγύγου και του Δευκαλίωνα, σχετίζονται με γεωλογικά φαινόμενα της ευρύτερης περιαιγαιακής περιοχής, που συνέβησαν κατά την τελευταία τήξη των παγετώνων και τις μεγάλες πλημμύρες που προκάλεσε αυτή, μεταξύ των ετών 14500 και 12500 Π.Α.Σ., επομένως πριν από την εποχή της Younger Dryas (12500 – 11400 Π.Α.Σ.), της τελευταίας δηλαδή από τις τρεις ψυχρές περιόδους (Oldest, Older και Younger Dryas), που διέκοψαν κατά διαστήματα την τάση αύξησης της θερμοκρασίας, η οποία είχε ήδη αρχίσει το 18000 Π.Α.Σ.
Στη συνέχεια η έρευνα επικεντρώθηκε στους ακόλουθους άθλους του Ηρακλή, οι οποίοι παρουσιάζουν γεωμυθολογικό ενδιαφέρον:
α. Η διαμάχη Ηρακλή και Αχελώου: Η πάλη του Ηρακλή με τον Αχελώο είναι η εκτροπή και διευθέτηση του ορμητικού σαν ταύρου ποταμού. Το φιδίσιο κορμί του είναι οι μαίανδροι που σχηματίζει, το δε κέρας που αποκόπτει ο Ηρακλής είναι η «ευθυγράμμιση» και παράκαμψη ενός μαιάνδρου, ο οποίος όταν αποκόπτεται από τη ροή του ποταμού, προσφέρεται ως εύφορη γη για καλλιέργειες. Η νέα γη, αποστραγγισμένη από τα νερά του ποταμού, είναι πραγματικά το κέρας της Αμαλθείας, δηλαδή το κέρας της Αφθονίας.
Με τον θεό - ποταμό Αχελώο συνάπτεται και ο μύθος των Εχινάδων, που έχει γεωμυθολογική σημασία. Σύμφωνα με τον Λατίνο ποιητή Οβίδιο (Μεταμορφώσεις, VIII, στ. 573 – 591), οι Εχινάδες ήταν πέντε ναϊάδες νύμφες, που κατοικούσαν δεξιά και αριστερά του Αχελώου. Πρόσφεραν θυσίες σε όλους τους θεούς, εκτός από τον Αχελώο. Εξ αιτίας αυτού του γεγονότος, αυτός οργίσθηκε και πέταξε τις Εχινάδες στη θάλασσα, μετατρέποντάς τις σε νησιά. Το μυθικό αυτό γεγονός υποκρύπτει ένα γεωλογικό συμβάν. Είναι διαπιστωμένο ότι πριν από 18000 χρόνια οι Εχινάδες νήσοι ήταν προέκταση της ξηράς της Αιτωλοακαρνανίας. Ανέβηκε, λοιπόν, η στάθμη της θάλασσας σιγά σιγά και κατέκτησε την ξηρά, αφήνοντας να προεξέχουν μόνον οι λόφοι. Αυτή η διεργασία ξεκίνησε 16.000-18.000 χρόνια πριν. Και στην περίπτωση αυτή ο μύθος αποδεικνύεται αληθινός.
β. Ο μύθος του Ηρακλή και του Λίχα: Ο Ηρακλής λόγω των αφόρητων πόνων που του προκάλεσε ο χιτώνας τον οποίο του προσκόμισε κατ’ εντολή της Δηιάνειρας ο Λίχας, άρπαξε τον Λίχα και τον εκσφενδόνισε προς τη θάλασσα και κατά πάσα πιθανότητα προς τον βόρειο Ευβοϊκό Κόλπο. Τα κομμάτια του Λίχα σχημάτισαν τα νησάκια Λιχάδες και το όρος επάνω από το ακρωτήριο ονομάστηκε Λιχάς. Και σε αυτή την περίπτωση, ένα γεωλογικό γεγονός που είχε συμβεί στην περιοχή του Βόρειου Ευβοϊκού προ χιλιάδων ετών και σε κάθε περίπτωση μεταξύ των ετών 18000 και 6000 Π.Α.Σ., πιστώθηκε στον ήρωα Ηρακλή.
Τα Λιχαδονήσια είναι ηφαιστειακά νησιά. Η εμφάνιση των νησιών ίσως βέβαια να είχε σχέση με το ανεβοκατέβασμα του νερού, εξ αιτίας των κλιματοευστατικών κινήσεων της στάθμης της θάλασσας, αλλά και με την άνοδο και πτώση των νερών της παλαιολίμνης, που υπήρχε πριν 9.000 χρόνια στην περιοχή, εκεί όπου βρίσκεται σήμερα ο βόρειος Ευβοϊκός κόλπος.
γ. Ο μύθος του Ηρακλή και του Προμηθέα: Ο Προμηθεύς είναι μία θεότητα της φωτιάς, όπως προκύπτει από την κλοπή και τη μεταφορά του πυρός στους ανθρώπους. Άλλωστε και το όνομά του συσχετίζεται με τη σανσκριτική λέξη pramantha, που σημαίνει «καλάμι, που παράγει φωτιά», στην περιοχή του Ινδού ποταμού. Όμως το γεγονός της τοποθέτησης ενός θεού της φωτιάς επάνω σε βουνό, θα μπορούσε, κατά τους E. και P. Barber, να μάς οδηγήσει στη σκέψη ενός ηφαιστείου, διότι συνήθως ένα ηφαίστειο είναι ένα βουνό που έχει φωτιά στην κορυφή του. Το όρος επάνω στο οποίο ήταν προσηλωμένος ο Προμηθεύς, σύμφωνα με τον Αισχύλο και τον Απολλόδωρο, ήταν ο Καύκασος της Σκυθίας.
Πράγματι στην περιοχή που αναφέρουν οι αρχαίοι Έλληνες ότι ήταν προσηλωμένος ο Προμηθεύς, υπάρχει ένα ηφαίστειο, που θα μπορούσε να είναι ο ίδιος ο Προμηθεύς ως γεωλογικό φαινόμενο, το οποίο αποκρυσταλλώθηκε στον μύθο. Το ηφαίστειο αυτό είναι το Elbrus, που έχει ύψος άνω των 5.400 μέτρων, ανήκει στην οροσειρά του Καυκάσου και γειτονεύει με την ανατολική πλευρά της Μαύρης Θάλασσας. Πρόσφατες χρονολογήσεις των εκρήξεων του Elbrus προσφέρουν ένα πιθανό χρονοδιάγραμμα των αρχικών εκρήξεων, που οδήγησαν στην τεράστια φήμη του όρους αυτού. Μία σειρά εκρήξεων έγινε μεταξύ των ετών 5500 – 5200 π.Χ., μία δεύτερη μεταξύ των ετών 3300 – 2600 π.Χ. και μία τρίτη μεταξύ των ετών 1 – 100 μ.Χ. Πιθανόν λοιπόν η δεύτερη σειρά εκρήξεων του ηφαιστείου Elbrus, που ήταν και η πιο μακροχρόνια, να έδωσε το έναυσμα της δημιουργίας του μύθου του Προμηθέα, ο οποίος στην περιοχή του Καυκάσου έχει το όμοιό του στον μύθο του θεού Loki της Σκανδιναβικής μυθολογίας.
Στην περίπτωση λοιπόν που ο Προμηθεύς είναι ηφαίστειο, τί ακριβώς θα μπορούσε να ήταν ο αετός, που υπερίπτατο του Προμηθέα και έτρωγε το συκώτι του; Τα τεράστια φτερά του αετού θα μπορούσαν να είναι μία εικόνα του σύννεφου στάχτης, που εξέρχεται από το ηφαίστειο και εκτοξεύεται προς τον ουρανό. Αυτό μπορεί να φαίνεται ίσως υπερβολικό, αλλά δεν πρέπει να λησμονούμε πόσο κοινό είναι σε διάφορους λαούς να συσχετίζουν μείζονα καιρικά φαινόμενα με τις φτερούγες γιγάντιων πτηνών, όπως το Thunderbird, το πτηνό του κεραυνού, στην Αμερική.
δ. Ο μύθος της Λερναίας Ύδρας: Ο Ηρακλής προσπαθώντας να εξολοθρεύσει την Λερναία Ύδρα, άρχισε να κόβει ένα προς ένα τα κεφάλια του θηρίου. Η αποκοπή ενός κεφαλιού, που αντιπροσωπεύει μία εκροή νερού σε κάποιο καρστικό σημείο, πιθανόν κατέστη δυνατή με την τοποθέτηση ενός βράχου στο σημείο όπου ανέβλυζε το νερό, για να εμποδίσει την έξοδό του ή για να το αναγκάσει να ακολουθήσει άλλη διαδρομή. Εάν κάποιος τοποθετήσει ένα βράχο μπροστά στο στόμιο μιας καρστικής πηγής, το νερό θα αναβλύσει από δύο ή περισσότερα άλλα σημεία. Αυτή είναι η αιτία του γεγονότος ότι στη θέση ενός κεφαλιού που απέκοπτε ο Ηρακλής, φύτρωναν δύο άλλα.
ε. Ο μύθος του Αυγεία: Τα τεχνικά έργα, που συσχετίζονται με τον καθαρισμό της όνθου του Αυγεία δεν έγιναν κατά πάσα πιθανότητα στον χώρο της Ηλείας, αλλά στην περιοχή της Τίρυνθας, που κατά τον Μαριολάκο συσχετίζονται με την κατασκευή του μυκηναϊκού φράγματος της Τίρυνθας. Το φράγμα αυτό διατηρείται σε καλή κατάσταση, έχει διεύθυνση Βορρά-Νότου, μήκος 80-100 μέτρων, πλάτος βάσης 60 μέτρων και σωζόμενο ύψος 8 μέτρων. Η χρονολόγηση της κατασκευής του κατά τη διάρκεια της Υστεροελλαδικής ΙΙΙ Β περιόδου (1300-1200 π.Χ.) συμπίπτει με την περίοδο της μεγαλύτερης ακμής του Μυκηναϊκού πολιτισμού. Το τεχνικό αυτό επίτευγμα των Μυκηναίων μπορεί να συγκριθεί με τα αποστραγγιστικά έργα μεγάλης τάξεως στην Κωπαΐδα. Θα αποκτήσουμε όμως την βεβαιότητα ότι ο άθλος αυτός του Ηρακλή έγινε στην περιοχή της Τίρυνθας και όχι στην περιοχή των ποταμών Αλφειού και Πηνειού, μόνο εάν γίνει γεωαρχαιολογική έρευνα στην περιοχή της Δυτικής Πελοποννήσου και αποδειχθεί ότι δεν συνέβη εκεί το γεγονός που αναφέρεται στον μύθο.
στ. Ο μύθος των Στυμφαλίδων ορνίθων: Υπάρχει το ενδεχόμενο ο μύθος αυτός να συσχετίζεται με έργα διαχείρισης των υδάτων της λίμνης Στυμφαλίας, που είχαν γίνει κατά στους προϊστορικούς χρόνους. Το εύρος των υδάτων της λίμνης αυτής ποίκιλλε ανάλογα με τη βροχόπτωση και τον έλεγχο της απορροής τους από φυσικές ή τεχνητές καταβόθρες. Ο άθλος του Ηρακλή συσχετίζεται πιθανότατα με το έργο αυτό. Ενισχυτικό της ερμηνείας αυτής είναι και το γεγονός ότι υδραυλικά έργα αντίστοιχης αρχαιότητας και τεχνικής έχουν επισημανθεί και στη γειτονική της Στυμφάλου κλειστή κοιλάδα της Φενεού, που οι αρχαίοι τα απέδιδαν στον Ηρακλή.
ζ. Ο μύθος του Γηρυόνη: Γιατί ο Γηρυόνης έχει τρία κεφάλια και επίσης γιατί «κραυγάζει», πράγμα που ακριβώς σημαίνει το όνομά του; Ο «Γηρυόνης» είναι ένα γεωλογικό φαινόμενο, συνεπώς τα κεφάλια του μπορούν να νοηθούν το ένα μέσα στο άλλο, όπως τον περιγράφει ο Φιλόστρατος. Δηλαδή ομιλούμε για ένα συγκεντρικό διαπειρογενή πολυδακτυλιόσχημο κρατήρα τριών ομoκέντρων κύκλων. Εφόσον λοιπόν ισχύουν τα ανωτέρω, τότε η «κραυγή» του οφείλεται στο ότι στον συγκεντρικό κρατήρα του το συμπιεσμένο αέριο (μεθάνιο) που βρίσκεται μέσα στη γη, εκτονώνεται με ταχύτητα από κάτω προς τα πάνω, δημιουργώντας ήχο.
η. Ο μύθος του Άτλαντα: Ο Άτλας είναι, κατά τον Ηρόδοτο, ένα πολύ υψηλό όρος στη Βόρειο Αφρική, στενό και κυκλοτερές, που οι εντόπιοι το ονομάζουν κίονα του ουρανού. Το γεγονός όμως της μεταφοράς της στήριξης του ουρανίου θόλου από τον Άτλαντα στον Ηρακλή και αντιστρόφως, πιθανόν να / The purpose of this paper is to show that myths referring to activities of gods, demigods, of Hercules, but also to floods and other natural phenomena, have cores of truth, that is they are genuine myths.
The contrast between myth and reality applied by many is wrong, because it is based on the false notion that all myths are fake. However, traditional myths are genuine and that means that they contain at their core true events of geological, astronomical and historical content which are offered for interdisciplinary research.
Cores of myths can be proved through interdisciplinary research, given their relation to applied sciences. Myths are spiritual and cultural palimpsests bearing scars of their history, namely of their multiple-level use and crystallization.
Let us first present some definitions of ancient writers on mythology. Indicatively, we quote two of them.
a. According to Plato (Critias, 109 e 1 – 110 a 6), mythology, that is a reasonable interpretation of myths, is a very careful and systematic investigation and research of past events.
b. According to Plutarch of Chaeronea (On Daedali of Plataea, fr.157, 16 - 21), the old science of physics was a physical speech hidden deep within myths. So, according to Plutarch, genuine myths are scientific speeches hidden deep within wraps made up of myths and formulated with cryptic words and innuendoes.
In the next chapter, which discusses the interpretation of myths, the principles useful and necessary to penetrate the myths’ cores of truth are identified.
We then approach the geo-mythology and explain its essence. Specifically, the term "geo-mythology" was coined by an American geologist and volcanologist, Dorothy Vitaliano. According to her, geo-mythology is an interdisciplinary analysis of genuine myths, which leads to the identification of geophysical and possibly other events, astronomical or historical, that underlie them. Sometimes this analysis provides valuable information and knowledge about floods, which are preserved under a mythical wrap in the traditions of peoples, but also on otherwise unknown ancient earthquakes, seismic sea or lacustrian tsunami waves, technical structures and unknown astronomical phenomena (comet passes, eclipses, meteor falls, changes in the north pole of the celestial sphere, correlations of constellations with specific heroes, etc.) that occurred in the distant past.
We then explore the three cataclysms of the Greek tradition, the labours and works of Hercules, which present a geo-mythological interest, while proposing specific further research areas for better documentation.
Finally, it investigates the osmosis of cultures of the eastern Mediterranean and answers the question if the Greek mythology reflects geological and climatic changes that rather occurred in the broader Aegean area or elsewhere in the world.
In the chapter which discusses the interpretation of myths, the principles useful and necessary to penetrate the myths’ cores of truth are identified.
However, to perform properly the interpretation of myths of a geological and astronomical texture, comprehensive knowledge is required in the fields of geology, astronomy, archaeology, philology, history, comparative mythology and anthropology. The geological, astronomical and general scientific study of mythology can reveal encoded memories of geological and astronomical events of the past, thus providing a reservoir of scientific data. On the other hand, it also helps give a new perspective on historical, archaeological and anthropological research, opening windows in the fields of knowledge that illuminate the early conception of the world and improve the human self-knowledge.
Following this, the paper deals with the three cataclysms of the Greek tradition, which are offered for geo-mythological research.
Specifically, Diodorus Siculus writes on the flood of Dardanus: "This flood has in principle happened because the mouth around the Cyanean Rocks has opened, a site where the Symplegades Rocks are located (their location was probably close to the exit of the Bosporus to the Black Sea); then opened the mouth of the Hellespont. This occurred because the Sea of Pontus, that is the water body of the Black Sea, which until then was a lake, was filled by the waters of rivers that flow into it, resulting to its level rising so much that it has overflowed the Strait of Bosporus, filled the Propontis and then, having overflowed the Strait of Hellespont as well, has rushed out into the Aegean. The result was the flood of a large coastal area, not only in Asia but also in Samothrace".
According to the research conducted, the flood of Dardanus took place in two phases: one in which the waters of the Black Sea poured into the Aegean Sea (between 14,500 and 12,500 Before Present - BP) and one in which the waters of the Aegean Sea, after the opening of the Strait of Bosporus, poured under the form of a large waterfall in the Black Sea around year 7,600 BP (5,600 BC.). This second phase of the cataclysm has probably triggered the creation of the cataclysm myths of Atrahasis, Ziusudra, Utnapistim and Noah. However, these two phases of the flood of Dardanus require additional systematic geological, geophysical and underwater archaeological research to be fully documented.
Concerning the flood of Ogyges, Hellanicus writes that it occurred one thousand twenty years before the first Olympiad. Given that the first Olympiad is placed in the year 776 BC, it results that this flood took place in 1796 BC. However, the correlation of Ogyges with Saturn, the Titans and the geological events of Thessaly suggests that the namesake flood should have probably taken place in a very old age, most probably between 14,500 and 12,500 BP. This variant, however, requires further geological research to be documented, too.
Finally, the flood of Deucalion is related to three different benchmarks:
a. To the Corinthian Gulf. This version has been fully documented by Lykoussis and others, according to whom the gulf has repeatedly been transformed from a lake to a sea basin and vice versa during the Upper Pleistocene (126,000 to 10,000 BP), which is due to the variation of global sea level and the small depth of the Strait of Rio – Antirio.
The Corinthian gulf remained isolated from the Mediterranean Sea until 13,000 years BP. The latter date is the limit for lake subsidence and the establishment of sea conditions within. With the influx of sea water into the Gulf coastal areas flooded, including the region of the then Phocis, which is also correlated to the flood of Deucalion. Deucalion survived thanks to the construction of a raft, which ran aground on Mount Parnassus. In all likelihood, however, the geographical term "Parnassus" is not only linked with the namesake mountain, but with a broader region, which includes the mountain.
b. To Thessaly. Concerning this version, Apollodorus writes that the flood of Deucalion occurred when the mountains of Thessaly separated, which probably took place between 14,500 and 12,500 BP. In this period significant climatic and geological upheavals have been noted around the globe. If drilling takes place in Thessaly, it will be possible to prove if one or more floods have really occurred in the region. The drilling cores can be dated.
Moreover, on the relationship of the flood of Deucalion with Thessaly and Parnassus, Paulus Orosius, Latin author of the 5th century AD, writes that this cataclysm took place 810 years before the creation of Rome (which occurred in year 753 AD), when Amphictyon was King of Athens, the third one after Cecrops. During the years of his reign, flood waters inundated most of the peoples of Thessaly and only a few survived, resorting to mountains and especially Parnassus, whose region was then under the reign of Deucalion who, after receiving by boats those who fled to him, took care of them and fed them on the twin peaks of Parnassus. Because of this fact, it is widely spread that the human race was re-created by him.
However, this version needs further scientific investigation as well.
c. The Parian chronicle, on the other hand, without associating the flood of Deucalion with a specific region, considers it of a much later era. Specifically, it says that the flood of Deucalion took place 1,265 years before the writing of the Chronicle. Since this Chronicle was written in the year 264 / 3 BC, during the reign of the Athenian archon Diognitos, the flood must have occurred in the year 1529 / 8 BC. There is always a possibility, however, that the flood mentioned in the Parian chronicle is a local flood of a later date in the 2nd millennium BC, which has been preserved with the same name and which should be confirmed by geological research in the area of Attica-Boeotia.
In conclusion, it is concluded that all three cataclysms of the Greek tradition, of Dardanus, Ogyges and Deucalion, are related with geological phenomena of the wider Aegean region, which occurred during the last melting of glaciers and the great flood caused, among 14,500 and 12,500 years BP, therefore before the time of the Younger Dryas (12,500 – 11,400 BP), i.e. the last of the three cold periods (Oldest, Older and Younger Dryas), which periodically interrupted the warming trend, which had already started in 18,000 BP.
Subsequently, investigation was focused on the following labours of Hercules, which present a geo-mythological interest:
a. The controversy between Hercules and Achelous: The struggle of Hercules with Achelous corresponds to the diversion and settlement of the river rushing like a bull. His serpentine body represents the meanders he forms, and the horn cut out by Hercules is the "alignment" and deviation of a meander which, when cut off from the flow of the river, is offered as a fertile land for crops. The new land, drained by the waters of the river, is really the horn of Amalthea, i.e. the horn of plenty.
With the God - River Achelous is also linked the legend of the Echinades, which has a geo-mythological importance. According to the Latin poet Ovid (Metamorphoses, VIII, f573 - 591), the Echinades were five Naiads, nymphs who lived on both sides of the river. They used to bring sacrifices to all the gods, except from Achelous. Because of this, he got angry and flew the Echinades into the sea, turning them into islands. This legendary event conceals a geologic event. It is established that 18,000 years ago the islands Echinades were an extension of the land of Aitoloakarnania. The sea level, thus, gradually increased and conquered the land, leaving only hills protruding. This process began 16,000-18,000 years ago. Again the myth proves to be true.
b. The myth of Hercules and Lichas: Hercules, because of the intolerable pain caused by the robe Lichas produced to him at the behest of Deianeira, grabbed Lichas and hurled it towards the sea, probably to the northern Euboean Gulf. Pieces of Lichas formed the islands called Lichades, and the mountain above the promontory was named Lichas. In this case, too, a geological event which had happened in the northern Euboean Gulf before thousands of years and in each case between 18,000 and 6,000 BP, was credited to the hero Hercules.
Lichades are volcanic islands. The emergence of the islands may of course be connected with the lowering or rising of the waters because of climatic-eustatic movements of sea level, but also with the rise and fall of the waters of an ancient lake that existed 9,000 years ago in the region, where is currently located the northern Euboean Gulf.
c. The myth of Hercules and Prometheus: Prometheus is a god of fire, as it results from the theft and transfer of fire to humans. Besides, his name is correlated to the Sanskrit word pramantha, meaning "reed, which produces fire" in the Indus River region. However, the fact of placing a god of fire on a mountain could, according to E. and P. Barber, lead us to the thought of a volcano, because usually a volcano is a mountain that has fire on top. The mountain upon which Prometheus was nailed, according to Aeschylus and Apollodorus, was the Caucasus of Scythia.
Indeed, in the area indicated by the ancient Greeks as the site where Prometheus was nailed, there is a volcano that could be Prometheus himself as a geological phenomenon which has crystallised in the myth. This volcano is Elbrus, which stands over 5,400 meters, belongs to the Caucasus Mountains and is adjacent to the eastern side of the Black Sea. Recent dating of Elbrus eruptions offer a possible timetable of the initial eruptions that led to the tremendous reputation of this mountain. A series of eruptions took place between the years 5,500 – 5,200 BC, a second between the years 3,300 – 2,600 BC and a third between the years 1 - 100 AD. So probably the second series of volcanic eruptions of Elbrus, which was the longest, spurred the creation of the myth of Prometheus, who in the Caucasus region has the like in the myth of the god Loki, in Norse mythology.
If, then, Prometheus was a volcano, what could exactly be the eagle, which would flow over Prometheus and eat his liver? The huge wings of the eagle could be an image of the ash cloud getting out of the volcano and ejected skyward. This may perhaps seem excessive, but we must remember how common it is in several nations to correlate major weather phenomena with giant bird wings, like the Thunderbird, the bird of thunder, in America.
d. The myth of Hydra: Hercules, when trying to kill the Hydra, began by cutting one by one the heads of the beast. Pinching a head, which represents an outflow of water in a karst point, was probably made possible by placing a rock at the point where water vents to prevent its exit or cause it to follow another path. If one places a rock in front of the mouth of a karst spring, the water vents from two or more other places. This is the cause of the fact that in the place of a head cut by Hercules, two more grew.
e. The myth of Augeas: The technical works correlated to cleaning the dung of Augeas probably did not take place in the area of Elis, but in the area of Tiryns where, according to Mariolakos, are correlated to the construction of the Mycenaean dam of Tiryns. This dam is preserved in good condition, is directed north-south, and has a length of 80-100 meters, a base width of 60 meters and preserved height of 8 meters. The dating of its construction during the Late Helladic IIIB period (1,300-1,200 BC) coincides with the period of greatest prosperity of the Mycenaean civilization. This technical achievement of the Mycenaeans may be compared to the drainage works of great scale around the Lake Copais. However, we shall only be assured that this labour of Hercules took place in the area of Tiryns and not in the area of the rivers Alpheus and Peneus if geo-archaeological research is performed in the Western Peloponnese region and proves that the event mentioned in the myth has not happened there.
f. The myth of the Stymphalian Birds: There is a possibility that this myth is correlated to water management works in Lake Stymphalia, which had taken place in prehistoric times. The range of lake waters varied depending on rainfall and runoff control through natural or artificial sinks. The labour of Hercules is probably correlated to this project. Supporting this interpretation is the fact that water works of corresponding oldness and technique have equally been identified in the neighbouring to Stymphalos, Feneos valley, works which the ancients attributed to Hercules.
g. The myth of Geryon: Why does Geryon have three heads and, also, why does he "scream", which is exactly what his name mean? "Geryon" is a geological phenomenon, so his heads can be understood as being one inside another, as described by Philostratus. So, we talk of a concentric, multiple-ring-shaped crater shaped by fire, consisting of three concentric cycles. If the above is valid, then his "scream" is due to the fact that, in its concentric crater, the compressed gas (methane) found in the earth blasts rapidly from the bottom up, creating sound.
h. The myth of Atlas: Atlas is, according to Herodotus, a very high mountain in North Africa, narrow and circular, which the natives called the column of the sky. The fact of the transfer of support of the sky dome from Atlas to Hercules and vice versa might also have an astronomical significance.
Specifically, on account of the phenomenon of equinox precession, a change in the position of the earth's axis modifies also the poles of the celestial sphere, tracing circles, the northern and southern one, whose completion requires 25,796 years. Today, the north pole of the sky is in a distance of one degree from the "alpha" star of the Little Bear. During the third millennium BC, the polar star was Thuban or "alpha" of the constellation of Draco. At the end of the eleventh millennium BC, the north pole of the sky was among the stars "Iota" and "Theta" of the constellation of Hercules. The transfer, therefore, of support of the sky from Atlas to Hercules probably means this change in the north pole of the sky.
Even the killing of the dragon that guarded the apples of the Hesperides by Hercules may have astronomical significance. The north pole of the sky was during the third millennium BC in the star Thuban or "alpha" of the constellation of Draco. Later, the north pole of the sky moved. This move resulted in the constellation of Draco as the north pole being sidelined, or, according to the mythical terminology, Draco being "killed". Since it was then considered that Draco (the dragon) was "killed" a great hero such as Hercules should have killed him. In other myths as dragon killers appear Apollo, who killed the dragon Python in Parnassus, Jason, who killed the dragon in Colchis with the help of Medea in order to grab the Golden Fleece, and finally Cadmus, who killed the dragon in Thebes and sowed his teeth, from which sprouted wickers.
Another problem investigated is whether there was a cultural osmosis in the eastern Mediterranean. Some cases are indicative. It is worth mentioning the following examples:
a. The battle of Zeus with Typhoeus / Typhon, which is very similar to the Hittite "Myth of Illuyankas", where the dragon Illuyankas fights against Teshub, the god of weather.
b. The labours of Ninurta: There are striking similarities between the labours of the Sumerian god Ninurta and the corresponding ones of Hercules, demonstrating the mythological osmosis and the merge of elements of one culture into another. Ninurta's fame is based on a series of twelve "labours". He has defeated twelve mythical monsters, including a wild bull, a deer, a lion which was "the terror of the gods", and a seven-headed serpent. Ninurta is usually identified with the form of a god bearing a mace, bow and lion skin, depicted on Mesopotamian seals, and its association with Hercules becomes inevitable.
In the latter part of the paper we investigated the question whether Greek mythology reflects geological and climatic changes that occurred in the broader Aegean area or elsewhere in the world.
This question was answered by a combination of views expressed by Sakellariou (historian), Hourmouziadis (archaeologist), Mariolakos (geologist), Renfrew (archaeologist), Sampson (archaeologist), Cavalli-Sforza (geneticist), Triantafyllidis (geneticist) and Skoglund (biologist), and by investigation of linguistic, archaeological, geological, mythological and genetic data. The conclusion that emerges is that probably the inhabitants of today's Greek territory who evolved with this particular cultural identity easily recognized since the time of Homo Sapiens, 50,000 BP, even if during the prehistoric times they were not aware of their common origin, they must have had continuous presence in the Aegean area, at least for the last ten thousand years.
Among other things, it should be noted that the paper deals with geo-mythological issues with a meticulous, where possible, use of ancient Greek and Latin sources.
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Extreme rainfall distributions : analysing change in the Western CapeDe Waal, Jan Hofmeyr 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2012. / Severe floods in the Western Cape have caused significant damage to hydraulic structures, roads and other infrastructure over the past decade. The current design criteria for these structures and flood return level calculations are based on the concept of stationarity, which assumes that natural systems vary within an envelope of variability that does not change with time. In the context of regional climate change and projected changes in rainfall intensity, the basis for these calculations may become unrealistic with the passage of time. Hydraulic structures and other infrastructure may become more vulnerable to damaging floods because of changing hydroclimatic conditions. This project assesses the changes in extreme rainfall values over time across the Western Cape, South Africa.
Using a Generalised Pareto Distribution, this study examines the changes in return levels across the Western Cape region for the periods 1900-1954 and 1955-2010. Of the 137 rainfall stations used in this research, 85 (62%) showed an increase in 50-year return level, 30 (22%) a decrease in 50-year return level and 22 (16%) stations displayed little change in rainfall intensity over time. While there were no clear spatial patterns to the results, they clearly indicate an increase in frequency of intense rainfalls in the latter half of the 20th and early 21st century. The changes in return level are also accompanied by a change in the frequency of high intensity 2-3 day long storms. 115 (84%) of the 137 rainfall stations showed an increase in the frequency of long duration, high intensity storms over the data record. This change generates a shifting risk profile of extreme rainfalls, which, in turn, creates challenges for the design of hydraulic structures and any infrastructure exposed to the resulting damaging floods. It can therefore be argued that it is inappropriate to design structures or manage water resources assuming stationarity of climate and that these principles should be assessed in order to reduce the risk of flood damage owing to increasing storm intensity.
KEY WORDS
Flood Risk, Stationarity, Disaster Risk, Hazard, Extreme Rainfall, Generalized Pareto Distribution, Climate
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The impact of high rainfall and flood events on Eucalyptus camaldulensis distribution along the central Breede RiverRaath, Gideon 04 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Eucalyptus camaldulensis Dehnh., or River Red Gum, is a commercially valuable yet recognised
invasive alien plant (IAP) of riparian zones throughout South Africa. The invasive potential of E.
camaldulensis is widely recognised, with specific regulations aimed at the management of E.
camaldulensis. E. camaldulensis is known to use large amounts of water, reduce biodiversity,
change river morphology and impact hydrological regimes of rivers. In the native range throughout
Australia, E. camaldulensis displays a distinct relationship between rainfall, and flood events, for
seed dispersal, germination and establishment, and consequently spatial extent, yet little is known
about the relationships in the South African context. The aim of this project was to assess the
impact of high rainfall and flood events on the establishment and distribution of E. camaldulensis
along the Middle Breede River, between Worcester and Swellendam in the Western Cape, by
establishing the current spatial extent of E. camaldulensis along the river, identifying flood events
since 1950 and evaluating the impact rainfall and flood events had on the spatial extent thereof.
Aerial imagery, rainfall, discharge and river level data was obtained dating back to 1980, as well as
field data comprising of GPS-bounding of E. camaldulensis stands. Additionally, density
measurements were obtained and interviews conducted with land users. Spatial analysis of aerial
imagery, coupled with perimeter (GPS) data and density data were used to conduct spatio-temporal
analysis, employing GIS and conventional statistical approaches to address the various objectives.
Results indicated E. camaldulensis stands had a small overall increase in spatial extent since 1980.
Flooding and rainfall events coincided with an increase in occurrence of E. camaldulensis with
elevated river levels and frequent flooding, while spatial variation of this relationship was observed.
The hydrological regime of the Breede River coincides with a slow increase in spatial extent of E.
camaldulensis stands, but no affirmation of a positive real-world relationship was possible using the
available data. Results further suggested, based on the current age class composition, that existing
stands originated roughly during 1980, possibly due to commercial forestry related seeding into the
river. Reduced fragmentation between stakeholders, educational programmes and improved
reporting systems were recommended for improved IAP management within the area. / AFRIKAANSE OPSOMMING: Eucalyptus camaldulensis, of Rooibloekom (RB), is ‘n waardevolle kommersiële, maar erkende
indringer plantspesie (IP) wat veral oewersones in Suid-Afrika indring. Die indringerpotensiaal van
E. camaldulensis is welbekend, en spesifieke regulasies, gemik op die bestuur van RB en ander
spesies is reeds aangeneem. E. camaldulensis is veral bekend vir sy hoë watergebruik, sy
vermindering van biodiversiteit, sy vermoë om riviervorme te verander en sy algehele impak op die
hidrologiese patroon van riviere waarmee dit in aanraking kom. In sy oorspronklike
verspreidingsgebied in Australië toon E. camaldulensis ‘n bepaalde verhouding tussen reënval en
vloedgebeurtenisse vir saadverspreiding, ontkieming en vestiging en derhalwe die ruimtelike
verspreiding van die spesie; alhoewel hierdie verhouding in die Suid-Afrikaanse konteks steeds
redelik onverduidelik bly. Die doelwit van hierdie studie was dus om die impak van hoë reënval en
vloedgebeurtenisse op die ruimtelike verspreiding en vestiging van E. camaldulensis teenaan die
Middel Breëde Rivier, spesifiek tussen Worcester en Swellendam, te evalueer. Hierdie doelwit was
bereik deur die historiese ruimtelike verspreiding teenaan die rivier te meet, hoë reënval en
vloedgebeurtenisse vanaf 1980 te identifiseer, en die huidige verspreiding en omtrek met GPS te
meet. Digtheidafmetings, sowel as onderhoude met belanghebbendes teenaan die rivier was ook
opgeneem. Visuele interpretatasie van lugfotos, sowel as omtrek (GPS) en digtheid-data was
gebruik om ruimtelike analise uit te voer, deur die gebruik van GIS en konvensionele statistiese
metodes, ten einde die doelwitte te evalueer. Resultate dui aan dat E. camaldulensis areas ‘n klein
algemene groei getoon het sedert 1980. Hoë-reënval en gereëlde vloedgebeurtenisse het ook
gepaard gegaan met ‘n groei van E. camaldulensis oppervlak, alhoewel hierdie verhouding
ruimtelike variasie getoon het, met ‘n algemene groei patroon gemerk oor die volledige
studietydperk. Ook geen stimulerende verhouding kon vanuit die beskikbare data bevestig word nie.
Addisionele resultate het aangedui dat die verspreiding van E. camaldulensis ongeveer 1980
onstaan het, moontlik as gevolg van kommersiële bosbou-aanplanting en verwante saadverspreiding
in die rivier vanaf daardie tyd. Aanbevelings ten opsigte van verbeterde indringerbestuur sluit in die
beperking van huidige fragmentasie tussen belanghebbendes en betrokke verwyderingsorganisasies,
addisionele onderrigprogramme sowel as die verbetering van terugvoersisteme.
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Méthodologie pour l’analyse et la prévention du risque d’accidents technologiques induits par l’inondation (Natech) d’un site industriel / Risk analysis methodology for the prevention of technological accidents triggered by flooding of industrial facilities (Natech)El HAJJ, Carine 07 November 2013 (has links)
Un évènement Natech est un accident TECHnologique provoqué par l’impact d’un aléa NAturel sur une installation industrielle. Cet accident peut porter atteinte à l’extérieur de l’emprise du site, aux personnes, aux biens ou à l’environnement. L’objectif de ce travail est de mettre au point une méthodologie pour l’analyse et la prévention du risque d’accidents technologiques induits par l’inondation (Natech inondation) d’un site industriel. La méthodologie repose, dans un premier temps, sur une étude des Retours d’Expériences. Il a été identifié que les accidents Natech sont imputables à un rejet de matières dangereuses sur des équipements dits critiques endommagés directement ou indirectement par les eaux d’inondation. Les rejets de matières dangereuses vont amener à trois types d’accidents (incendie, pollution, explosion). Dans un deuxième temps, la méthode MADS-MOSAR a été adaptée à l’application aux accidents Natech inondation. L’analyse a abouti à cinq scénarios génériques d’accident Natech inondation sous forme de cinq nœuds papillons. Une soixantaine de Mesures de Maîtrise de Risque de prévention et de protection ont été identifiées. La validation de la complétude et de la plausibilité des nœuds papillons génériques est effectuée, d’une part, à l’échelle du secteur d’activité de traitement de surface et, d’autre part, à l’échelle spécifique d’établissements industriels. Ce travail a abouti à un outil de diagnostic de la vulnérabilité d’une installation industrielle aux accidents Natech inondation, accompagné d’un catalogue de MMR. Enfin, ce diagnostic a été appliqué sur un site industriel afin d’évaluer son mode opératoire et de l’enrichir par l’expérimentation. / A Natech accident is the impact of a NAtural event on an industrial plant (such as an ICPE- Classified Installation for the Environmental Protection). The impact can trigger a TECHnological accident, damaging the vicinity of the industrial facility (inhabitants, their properties and the environment). The final objective of this work is to develop a risk analysis methodology for the prevention of technological accidents triggered by flooding of industrial facilities. Therefore, the work begins with an analysis of past technological accidents triggered by floods. Thus, it was identified that Natech accidents are the consequences of hazardous materials releases from critical equipment, which in turn are damaged directly and indirectly by flood waters. Depending on the type of hazardous substances released, three categories of technological accidents are observed (fire, pollution and explosion). Afterwards, a risk analysis methodology was developed. It is mainly based on the MADS-MOSAR method, which was modified in order to be adapted to the Natech issue. The analysis resulted in the identification of five generic scenarios of technological accidents triggered by floods that can occur within an industrial installation. These scenarios were represented using the bow-tie tool. Then, around sixty preventive and protective measures were identified. The validation of the elaborated scenarios was done, on one hand, in the surface treatment industrial sector and, on the other hand, in two specific industrial facilities. The validation phase helped to test the completeness and plausibility of the generic scenarios, as well as the relevance of the measures previously identified. Furthermore, the validated scenarios were used to develop a checklist helping operators to decrease the vulnerability of their industrial facilities to technological accidents triggered by floods, along with a catalog of preventive and protective measures. Finally, the tool was applied to an industrial installation in order to enhance it and test its relevance by operators.
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Využití mezikrajské a mezinárodní pomoci sil a prostředků záchranných složek při povodních / Use of interregional and international aid forces and means of rescue services during floodsSVOBODA, Radek January 2015 (has links)
This diploma thesis deals with using of interregional and international aid forces and means of rescue services during floods. The first chapter describes Civil Protection legislative conditions, coordination, capacity, monitoring tools and information support in the Czech republic, EU and UN. The second capter contains cases study "Floods in BiH, Serbia and Croatia 2014", "Floods in Czech republic 2002". The case studies are focused on EU Civil Protection Mechanism response. Other part describes and compares three High capacity pumping teams. Aim of the last part is design optimization of emplacement of the modules in EU.
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[en] THE USE OF PERMEABLE CONCRETE PAVEMENT FOR THE ATTENUATION OF URBAN FLOODS / [pt] USO DO PAVIMENTO PERMEÁVEL DE CONCRETO PARA ATENUAÇÃO DE CHEIAS URBANASPATRICIA TAINA DA SILVA C ANTUNES 16 February 2018 (has links)
[pt] A pesquisa analisou o material concreto permeável visando a sua aplicação como revestimento de pavimentos permeáveis para atenuação de cheias urbanas. Desta maneira, diversas misturas foram estudadas experimentalmente, objetivando determinar suas características hidráulicas e mecânicas. Com base nos resultados experimentais e no uso pretendido em calçadas, foi definida a mistura mais adequada. A fim de analisar o impacto desta solução no escoamento superficial, foi escolhida a bacia hidrográfica do Rio dos Macacos localizada no Bairro Jardim Botânico no Rio de Janeiro a qual apresenta problemas recorrentes de inundação. Em função das características da bacia e em critérios mecânicos e hidráulicos do pavimento permeável de concreto, foram escolhidas as áreas para a sua aplicação e opavimento foi dimensionado. A bacia estudada foi modelada com auxílio dosoftware Storm Water Management Model para os cenários antes e após a aplicação dos pavimentos permeáveis de concreto em calçadas. Por fim, foi estimado o custo direto da solução proposta. Os resultados do estudo experimental do concreto permeável demonstraram que o material possui permeabilidade e resistências mecânicas adequadas para aplicação em calçadas. Os resultados do modelo computacional, obtidos através da comparação de hidrogramas de cheia, evidenciaram satisfatório amortecimento. A análise de custo demonstrou que a solução é economicamente viável. / [en] New techniques of urban drainage have emerged in order to mitigate the negative effects of urbanization. Initially, in the United States in 1970 denominated Best Management Practices (BMPs) and then in United Kingdom in 1980 as Sustainable Urban Drainage Systems (SUDS). The goal of these techniques is to reproduce the natural hydrological cycle, mitigating flood peaks and reducing diffuse pollution through infiltration, retention and transport devices such as green roofs, percolation trenches and pervious pavements. (Canholi, 2014). Unlike traditional pavements, pervious pavements allow the infiltration of rainwater on the surface. The infiltrated water is stored temporarily before use, infiltration into the soil, or downstream controlled discharge. According to Field et al (1982) and Mullaney and Lucke (2013), all types of pervious pavement share the same objectives, which are: to allow the infiltration of water on its surface; reduce the increase in the rate and volume of runoff; and improve degradation of water quality resulting from urbanization and land use change. Depending on the soil permeability, they still have the advantage of allowing the recharge of the aquifers.
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Identificação e avaliação de eventos extremos na bacia hidrográfica do Rio Piranga / Identification and evaluation of extreme events in Piranga River WatershedSalvador, Mateus da Mota 20 February 2014 (has links)
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Previous issue date: 2014-02-20 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Floods and landslides are among the natural disasters most frequent that cause more economic and social losses in the world. In Brazil, a critical place is the Piranga River Watershed (PRW), located in Minas Gerais State and which comprises the Doce River headwaters. The setting is mainly due to the occurrence of extreme rainfall events associated with lack of planning and management of soil and inadequate occupation. Given the above, it is important to look after tools that help in interpreting information regarding the environment dynamics and also, tools that can identify, understand and predict the impact of changes caused to the environment. Therefore, this study was developed in two parts, involving the occurrence of extreme events in the PRW. In the first was presented a methodology for landslidesusceptible areas identification with the support of field experiments and strategic decision analysis based on multi-criteria evaluation. In the second part, the objective was to calibrate and validate a hydrological model in order to assess the effect land cover changes on the watershed hydrology opposite major floods. It can be concluded that the proposed methodology allowed the identification of landslide-susceptible areas in good agreement with the conditions observed in the field. The hydrological model was able to represent with good precision the watershed hydrological behavior and the scenarios simulation indicated an increase trend of floods occurrence due to changes in land cover. It is expected that this study enables the improvement of landslides and floods understanding and also, that it contributes as a tool for risk management in the PRW. / Enchentes e deslizamentos de terra estão entre os desastres naturais mais frequentes e que causam mais prejuízos econômicos e sociais no mundo. No Brasil, uma região crítica é a Bacia Hidrográfica do Rio Piranga (BHRP), localizada no Estado de Minas Gerais e que abriga a nascente do Rio Doce. O cenário deve-se principalmente à ocorrência de eventos de precipitação extremos associados à falta de planejamento e manejo no uso do solo e à ocupação acelerada e inadequada. Diante do exposto, é importante a busca por ferramentas que ajudem na interpretação de informações referentes à dinâmica dos recursos ambientais e que possam identificar, compreender e predizer o impacto de alterações provocadas ao meio ambiente. Nesse sentido, desenvolveu-se este trabalho na forma de dois estudos envolvendo a ocorrência de eventos extremos na BHRP. No primeiro, apresenta-se metodologia para a identificação de zonas de suscetibilidade a deslizamentos de terra com apoio de experimentos de campo e análise estratégica de decisão por avaliação multicritérios. Já no segundo estudo, o objetivo foi calibrar e validar modelo hidrológico para avaliar o efeito das mudanças de cobertura do solo no comportamento hidrológico da bacia frente a grandes cheias. Conclui-se que a metodologia apresentada permitiu a identificação de áreas suscetíveis à ocorrência de deslizamentos de terra com boa concordância em relação às condições observadas em campo. O modelo hidrológico foi capaz de representar com boa concordância o comportamento hidrológico da bacia e a simulação de cenários indicou um aumento na tendência de ocorrência de enchentes devido às mudanças na cobertura do solo. Espera-se que os resultados deste estudo permitam aprimorar a compreensão sobre os deslizamentos e enchentes e que possam contribuir como ferramenta para gestão de riscos na BHRP.
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Hydrometeorological extremes in the Adige river basin, Italy / Hydrometeorologiska extremvärden i Adigeflodens avrinningsområde, ItalienGozzi, David January 2018 (has links)
This study aimed at describing the characteristics of daily precipitation and discharge extremes in the Adige river basin at the city of Trento. Annual maximum series for the period 1975−2014 were analyzed in terms of trends, seasonality indices and L-moments. A Mann-Kendall trend analysis showed a weak but significant signal of decreasing ex-tremes; the percentages of sites with significant negative trends were overall larger than the significance levels. Precipitation extremes were characterized primarily by autumn storms, while floods had a stronger seasonality with peaks occurring predominantly in June and July which indicated that the timing not solely explained by rainfall maxima. The Adige basin was found to be a homogenous region with respect to precipitation, but the results did not support a corresponding assumption for discharge. A regional fre-quency analysis was performed for precipitation data and found both the Pearson type III and generalized normal distributions to be adequate regional frequency distributions. The extreme daily precipitation at Trento with a 100-year return period was estimated to be between 114 and 148 mm/d. / Egenskaperna hos extremvärden av dygnsnederbörd och -vattenföring i Adigeflodens av-rinningsområde vid staden Trento undersöktes. Serier med årsmaxima för perioden 1975–2014 analyserades med avseende på trender, säsongsindex och L-moment. Trendanalys med Mann-Kendallmetod antydde en svag men signifikant signal om minskande extrem-värden, då andelen mätstationer med signifikant negativa trender överlag var större än signifikansnivån. Den extrema nederbörden karakteriserades huvudsakligen av höststor-mar, medan vattenföringen hade en starkare säsongsbundenhet då maxima inträffade främst under juni och juli. Vattenföringens extremvärden kunde därmed inte enbart för-klaras av nederbördsmaxima. Avrinningsområdet kunde betraktas som en homogen reg-ion för nederbörd, men resultaten gav inte stöd åt ett motsvarande antagande för vatten-föring. En regional frekvensanalys genomfördes för nederbördsdata och visade att Pear-son typ III och den generaliserade normalfördelningen var lämpliga regionala sannolik-hetsfördelningar. Över Trento uppskattades den extrema dygnsnederbörden med en åter-komstperiod på 100 år till mellan 114 och 148 mm/d.
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