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Morphology of urban conglomerations: experimental and theoretical modeling, and implications for everyday traffic Massimo Pica Ciamarra Dipartimento di.

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Presentation on theme: "Morphology of urban conglomerations: experimental and theoretical modeling, and implications for everyday traffic Massimo Pica Ciamarra Dipartimento di."— Presentation transcript:

1 Morphology of urban conglomerations: experimental and theoretical modeling, and implications for everyday traffic Massimo Pica Ciamarra Dipartimento di Scienze Fisiche Università di Napoli Federico II Crdc-AMRA Antonio Coniglio Physics and the city, Bologna, 15 Dic. 2005

2 Outline Motivation Urban morphology:empirical analysis theoretical modeling Evacuation Conclusions Motivation Urban morphology Evacuation Conclusions

3 Mt. Vesuvius Motivation Urban morphology Evacuation Conclusions People to be evacuated: 500.000 Eruption forecast Mt. Vesuvius estimate: 14 days -1980 Mt. St. Elena 24 h - 1991 Mt. Pinatubo 48 h - 1996 Mt. Ruapehu 6 days - ??? Mt. Vesuvius 14 days Population: 500.000 Mt. Vesuvius Naples Ercolano Pompei

4 Evacuation time Numbers People: 500.000 Safety distance: d = 50 Km Evacuation time v = 4 Km/h T = 12h 30m v = 20 Km/h T = 2h 30m v = 40 Km/h T = 1h 15m Congestion ? no yes ? Motivation Urban morphology Evacuation Conclusions

5 The road network: Rome 20 Km 1.5 Km Motivation Urban morphology1. Empirical analysis 2. Theoretical modeling Evacuation Conclusions

6 P.za Venezia 1.1 Km A grid element = # black pixels # pixels P.za Navona Via del Corso Via Nazionale Campidoglio 1.5 Km Maps: www.maporama.com 1px = 2 m 2 Motivation Urban morphology1. Empirical analysis 2. Theoretical modeling Evacuation Conclusions

7 0.3 0.2 0.1 10 20 30 40 0 Andamento di (r) per la città di Roma Motivation Urban morphology1. Empirical analysis 2. Theoretical modeling Evacuation Conclusions

8 Cluster growth: background Motivation Urban morphology 1. Empirical analysis 2. Theoretical modeling Evacuation Conclusions DLA: T.A. Witten and L.M. Sander, Phys. Rev. Lett. 47, 1400 (1981). M. Batty and P. Longley, Area 19, 215 (1987); M. Batty and P. Longley, Env. and Planning B 14, 123 (1987). M. Batty et. al., Env. and Planning A 21, 1447 (1989). Diffusion-Limited Aggregate Eden Model M. Eden, Proc. 4° Berkeley Symp. On Mat. Stat. and Probability, Univ. California. Press, (1961). J.D. Weeks et. al., J. Chem. Phys. 65, 712 (1976). L. Benguigui, Physica A 219, 13 (1995). r

9 Random walk cluster growth model Motivation Urban morphology 1. Empirical analysis 2. Theoretical modeling Evacuation Conclusions Assumptions: 1: 2: random walk with a drift Mean: St. Dev.: 3:

10 Growth probability Motivation Urban morphology 1. Empirical analysis 2. Theoretical modeling Evacuation Conclusions Probability of building a city unit in a point at a distance r form the center

11 Radial density Motivation Urban morphology 1. Empirical analysis 2. Theoretical modeling Evacuation Conclusions

12 Evacuation and bottlenecks: Rome 10 20 30 40 0.3 0.1 0.2 0.25 0.15 0.05 0 10 20 expansion compression expansion Motivation Urban morphology Evacuation Conclusions

13 Optimization of the evacuation process One entry ? Two entries ? Motivation Urban morphology Evacuation Conclusions

14 Entry ramps Q upstream Q exit Q in Q exit = Q upstream + Q in Entry ramp model p If we can insert a car in the main flow without causing accidents We insert the car with probability p p = 0: cars are never inserted p = 1: a car is inserted as soon as possible M. Pica Ciamarra, Phys. Rev. E 72, 066102, (2005). Simulation with the Extended Nagel - Schreckenberg model Knospe et. al., Phys. Rev. E 70, 016115 (2004). Q exit = Q(p 1,…,p n ) Motivation Urban morphology Evacuation Conclusions

15 p1p1 p2p2 0 1 0.5 0 1 Example: two entries – two lane road 1600 0 800 400 1200 Q (cars/h) (p 1, p 2 ) (0.35,0.5) Q 1 900 cars/h Q 2 700 cars/h Max: Motivation Urban morphology Evacuation Conclusions

16 1. Morphology of a city Empirical study of digital maps (resolution: 2m 2 ) Simple model of cluster growth (anal. solvable) Universality - Bottlenecks 2. Optimization of on-ramp entries Simulation of the extended Nagel-Schreckenberg model Control of the flux of entering cars

17 O posteri, o posteri si tratta di voi un giorno è lume all'altro e il dì precedente è norma per il dì che segue udite venti volte da che splende il sole se non sbaglia la storia arse il Vesuvio. Sempre con strage immane di chi a fuggir fu lento. Affinché dopo l'ultimo lutto più non vi colpisca io vi avviso. Questo monte ha greve il seno di bitume, allume, zolfo, oro, argento, nitro, di fonte d'acque. Presto o tardi si accende ma prima geme trema, scuote il suolo mescola e fumo e fiamme e lampi scuote l'aria, rimbomba, tuona, muggisce scaccia ai confini gli abitanti. Tu scappa finché lo puoi. Ecco che scoppia e vomita di fuoco un fiume che vien giù precipitando e sbarra la fuga a chi s'attarda se ti coglie e' finita: sei morto disprezzato apprese gli incauti e gli avidi cui la casa e le suppellettili furono più care della vita. Ma tu, se hai senno, di un marmo che ti parla di la voce non ti curar dei lari; senza indugi fuggi. E. Fonseca y Zunica, Vicerè (1632)

18 Radial density (r) Round cities r x y Motivation Urban morphology1. Empirical analysis 2. Theoretical modeling Evacuation Conclusions

19 DeathsVolcanoWhenMajor Cause of Death (no starvation) 36,417Krakatau, Indonesia1883Tsunami 29,025Mt. Pelee, Martinique1902Ash town of Saint Pierre 25,000Ruiz, Colombia1985Mudflows town of Armero 14,300Unzen, Japan1792Volcano collapse, tsunami 5,110Kelut, Indonesia1919Mudflows 4,011Galunggung, Indonesia1882Mudflows 3,500Vesuvius, Italy1631Mudflows, lava flows 3,360Vesuvius, Italy79Ash flows and falls 2,957Papandayan, Indonesia1772Ash flows 2,942Lamington, Papua N.G.1951Ash flows 2,000El Chichon, Mexico1982Ash flows 1,680Soufriere, St Vincent1902Ash flows 1,475Oshima, Japan1741Tsunami 1,377Asama, Japan1783Ash flows, mudflows 1,335Taal, Philippines1911Ash flows 1,200Mayon, Philippines1814Mudflows 1,184Agung, Indonesia1963Ash flows 1,000Cotopaxi, Ecuador1877Mudflows 800Pinatubo, Philippines1991Roof collapses and disease Volcanic Hazards: A Sourcebook on the Effects of Eruptions, Russell J. Blong (Academic Press, 1984).


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