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Statistical physics of transportation networks. Cieplak, Colaiori, Damuth, Flammini, Giacometti, Marsili, Rodriguez-Iturbe, Swift. Amos Maritan , Andrea Rinaldo.
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Statistical physics of transportation networks Cieplak, Colaiori, Damuth, Flammini, Giacometti, Marsili, Rodriguez-Iturbe, Swift Amos Maritan, Andrea Rinaldo Science 272, 984 (1996); PRL 77, 5288 (1996), 78, 4522 (1997), 79, 3278 (1997), 84, 4745 (2000); Rev. Mod. Phys. 68, 963 (1996);PRE 55, 1298 (1997); Nature 399, 130 (1999); J. Stat. Phys. 104, 1 (2001); Geophys. Res. Lett. 29, 1508 (2002); PNAS 99, 10506 (2002); Physica A340, 749 (2004); Water Res. Res. 42, W06D07 (2006)
1 1 1 1 1 4 3 1 1 3 1 2 1 1 12 1 1 2 1 16 3 6 1 2 25 Digital elevation map Spanning Tree
Scheidegger model – equal weight for all directed networks Huber, Swift, Takayasu .....
Peano Basin Random spanning trees (all trees have equal weight) Coniglio, Dhar, Duplantier, Majumdar, Manna, Sire …..
Dynamics of optimal channel networkexcellent accord with data Only able to access local minima Rinaldo & Rodriguez-Iturbe
Topology of optimal network 2: Electrical network 1: Random directed trees ½: River networks 0: Random trees
Finite size scaling – verified in observational data Maritan, Meakin, Rothman …..
Finite size scaling (contd.) Scheidegger model: H=1/2; Mean field: H=1; Random trees: dl = 5/4; Peano Basin: H = dl = 1
Universality classes of optimal channel networks in D = 2 3 universality classes none of which agrees with observational data
Sculpting of a fractal river basin • Landscape evolution equation: • erosion to local flow A(x,t) (no flow - no erosion) • reparametrization invariance • small gradient expansion Somfai & Sander, Ball & Sinclair
Non-local, non-linear equation – amenable to exact solution in one dimension Consequences in two dimensions: • Slope discharge relationship • Quantitative accord with observational data • Local minima of optimal channel networks are stationary solutions of erosion equation • Two disparate time scales – connectivity of the spanning tree established early, soil height acquires stable profile much later
Data (& More Recent Data) on Kleiber’s law Brown & West, Physics Today, 2004 B M