Investigation of surface deformation / movement in Sanitary Landfill areas using the Synthetic Aperture Radar Interferometry (InSAR) technique

73 σ.Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) "Γεωπληροφορική"Η βασική ιδέα στην παρούσα επιστημονική μελέτη είναι η εφαρμογή της Συμβολομετρίας ραντάρ απεικονίσεων στην παρακολούθηση των μετακινήσεων/ παραμορφώσεων του αναγλύφου μετά από ανθρώπινη παρέμβαση. Για την επίτευξη του στόχου αρχικά καθορίζεται η περιοχή μελέτης η οποία είναι ο Χώρος Υγειονομικής Ταφής Απορριμμάτων (ΧΥΤΑ) που βρίσκεται στη συμβολή των Δήμων Φυλής και Άνω Λιοσίων του Νομού Αττικής. Πρόκειται για μια περιοχή που τις τελευταίες δεκαετίες δέχεται διαρκείς παρεμβάσεις στο ανάγλυφό της εξαιτίας της δημιουργίας λεκανών υποδοχής απορριμμάτων και της επανεπίχωσής τους με απορρίμματα αλλά και εξαιτίας των εκσκαφών υγειούς εδάφους για την χωματοκάλυψη των εναποτιθέντων απορριμμάτων. Η προσέγγιση του αντικειμένου γίνεται με την εφαρμογή των βημάτων της Συμβολομετρικής διαδικασίας σε οκτώ ζεύγη εικόνων ραντάρ συνθετικού ανοίγματος (SAR) από τον δορυφόρο ENVISAT ASAR. Για την εφαρμογή της διαδικασίας δοκιμάζονται ως Ψηφιακά Μοντέλα αναφοράς τρία διαφορετικά DEM, τα δύο προερχόμενα από τους δορυφόρους SRTM και ASTER και το τρίτο που προέκυψε από ψηφιοποίηση χαρτών 1:5000 της Γεωγραφικής Υπηρεσίας Στρατού (ΓΥΣ). Αποτέλεσμα της όλης διαδικασίας είναι η δημιουργία ενός DEM από κάθε ζεύγος εικόνων. Η αξιολόγηση της ακρίβειας των παραγόμενων DEM γίνεται με την χρήση Τριγωνομετρικών σημείων της ΓΥΣ. Από τα ζεύγη εικόνων με τις μικρότερες κατακόρυφες υψομετρικές αποκλίσεις και λαμβάνοντας υπόψη ένα εκτιμώμενο μέσο σφάλμα, γίνεται η σύνθεση ενός "μέσου" DEM που προκύπτει από τα επιμέρους DEM με τον υπολογισμό του μέσου όρου των τιμών υψομέτρου για κάθε εικονοστοιχείο. Τέλος, από την αφαίρεση του DEM αναφοράς από το "μέσο DEM" προκύπτει ένας χάρτης με τις κατακόρυφες υψομετρικές μετακινήσεις / παραμορφώσεις. Τα αποτελέσματα παρουσιάζονται σε δισδιάστατη και τρισδιάστατη προοπτική απεικόνιση και συγκρίνονται με βάση σημεία γνωστού υψομέτρου μέσα στην περιοχή μελέτης, που έχουν προκύψει από επίγειες τοπογραφικές αποτυπώσεις. Τέλος, αναφέρονται τα βασικά συμπεράσματα που εξάγονται από τη συγκεκριμένη εφαρμογή της Συμβολομετρίας καθώς και οι προοπτικές εξέλιξης της έρευνας.The basic idea of this study is the surface deformation/ movement investigation and monitoring in areas with rigorous human intervention using the Synthetic Aperture Radar Interferometry (InSAR) technique. To start with, for the accomplishment of the initial aim, the area of investigation is defined to be the Sanitary Landfill which is located in the northwestern part of Attica. In the recent decades, the constant excavations of the healthy surface for the structure of basins and for the covering of the disposed waste as well as the simultaneous backfilling with waste had as a result significant changes in the surface. The Interferometric analysis process was applied using eight InSAR pairs of ENVISAT ASAR Single Look Comlex Images. The topogrpahic phase was estimated using suitable reference Digital Elevation Models (DEMs), two of them derived from the satellite SRTM and ASTER respectively and a third one derived by topographic maps with scale 1:5000 of approximate spatial resolution of 5m. As a result of the Interferometric process eight DEMs one of each image pair were generated. The investigation of the accuracy of DEM generation was based on three ground control points outside of the area of Landfill. From the sets with the lower vertical deviation, considering the estimated mean error a "median" DEM was extracted. Finally, the reference DEM was removed from the "median DEM" and a map with the final vertical deformations/ displacement was extracted. The results are presented in a two-dimensional and three- dimensional view and compared with ground control poins from the inside of the landfill, known from topographic measurements. At the end of the study the main conclusions of the application were outlined as well as the future prospects of research.Ζωή Σ. Γραμματικο

Unidentified insect in a petri dish, New South Wales, 12 May 1933 [picture].

Title devised from accompanying information where available.; Part of the: Fairfax archive of glass plate negatives.; Fairfax number: 825.; Condition: silvering.; Also available online at: http://nla.gov.au/nla.pic-vn6217552; Acquired from Fairfax Media, 2012

Implementation and effectiveness of the first community lifestyle intervention programme to prevent Type 2 diabetes in Greece. The DE-PLAN study

P>Aims To report our experience of implementing the first community-based lifestyle intervention programme to detect high-risk individuals and prevent the development of Type 2 diabetes mellitus (T2DM) in a general population sample in Athens, Greece (the DE-PLAN Study). Methods The Finnish Type 2 Diabetes Risk Score (FINDRISC) questionnaire was distributed to 7900 people at workplaces and primary-care centres. High-risk individuals were invited to receive an oral glucose tolerance test (OGTT) and, after excluding persons with diabetes, to participate in a 1-year intervention programme, based on bimonthly sessions with a dietitian. Results Three thousand, two hundred and forty questionnaires were returned; 620 high-risk individuals were identified and 191 agreed to participate. Recruitment from workplaces was the most successful strategy for identifying high-risk persons, enrolling and maintaining them throughout the study. The 125 participants who fully completed the programme (66 did not return for a second OGTT) lost on average 1.0 +/- 4.7 kg (P = 0.022). Higher adherence to the intervention sessions resulted in more significant weight loss (1.1 +/- 4.8 vs. 0.6 +/- 4.6 kg for low adherence). Persons with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) at baseline lost more weight than those with normal glucose tolerance (1.5 +/- 4.8 vs. -0.2 +/- 4.5 kg). The percentage of people with any type of dysglycaemia (IFG/IGT) was lower after the intervention (68.0% at baseline vs. 53.6% 1 year later, P = 0.009); 5.6% developed diabetes. Conclusions The implementation of a lifestyle intervention programme to prevent T2DM in the community is practical and feasible, accompanied by favourable lifestyle changes. Recruitment from workplaces was the most successful strategy

Changes in dietary habits and their association with metabolic markers after a non-intensive, community-based lifestyle intervention to prevent type 2 diabetes, in Greece. The DEPLAN study

Aims: The aim of the present study was to evaluate the impact on dietary and activity habits of a non-intensive, community based lifestyle intervention for type 2 diabetes prevention, in high-risk Greek individuals. Methods: A total of 191 high-risk persons were invited to participate in a one-year lifestyle intervention program, consisting of six bi-monthly sessions with a dietician. The dietary aims of the intervention were: reduction of saturated fat, sugars and refined cereals intake and at least five servings of fruits and vegetables, daily. Demographic, dietary, anthropometric, medical and biochemical indices were recorded at baseline and at the end of the intervention. Results: The intervention was completed by 126 participants. At study end, participants reported decreased whole fat dairies and processed meats consumption (p = 0.018 and 0.016, respectively), sugars (p=0.006) and refined cereals (p=0.045). Participants who improved their diet, decreased body weight (p=0.040), plasma triglycerides (p=0.020) and 2-h post-load plasma glucose (p=0.05) compared to those who had worsened their dietary habits. Total time spent daily on physical activity, remained unchanged throughout the intervention. Conclusions: The implementation of a group-based, non-intensive dietary counseling proved to be practical and feasible in " real-world" community settings and was accompanied by favorable dietary changes and health benefits. © 2011 Elsevier Ireland Ltd