1 A ‘river’ of rock, earth, and other debris saturated with water; differing from slides in that no shear plane exists. Flows are classified by the size of the particles: debris flow refers to coarse material; earth flow to soil; and mud flow to clay. See Quinta-Ferreira (2007) online Bull. Engineer. Geol. & Env. 66, 1 on the natural and man-made causes of an earth flow in Portugal, 2000; and Dowdeswell et al. (1987) ESPL 13, 8 reconstruct an active debris flow from mudlines. See also Stoffel and Bollschweiler (2007) Geophys. Res. Abs. 9 on the dendrogeomorphological reconstruction of a past debris flow.

2 The movement of goods, people, services, and information along a network. P. Dicken (2003) observes that flows of goods, people, and information are rising, based on changes in scale, and driven by innovations in information and communication technologies. Janelle in Hanson et al., eds. (2004) illustrates newly emerging systems of flows and nodes, and Hughes (2007) PHG 31, 4 reviews the geographical literature on the flows and networks of knowledgeable capitalism. Jensen (2006) Mobilities 1, 2 offers a ‘new’ perspective on flows in the contemporary city, and Carr et al. (2005) J. World Business 40, 4 write about talent flow—whereby economically valuable individuals migrate between countries. Spaces of flows are the networks that bind a world system of cities (M. Castells 1989).