ABSTRACT
Terrestrial surfaces are composed of regions with varied degrees of concavity and convexity. Physiographic and geomorphologic processes can be better explained by quantitative descriptions of these concavities and convexities. Valley and ridge connectivity networks are the abstract structures of concave and convex zones of terrestrial surfaces. The extraction of these abstract structures has been explained in this chapter. These abstract structures are important from the point of terrestrial surface characterization quantitatively via morphometry (Horton 1945), hypsometry (Strahler 1957), allometry (Maritan et al. 1996, Rodriguez-Iturbe and Rinaldo 1997, Sagar and Tien 2004), morphological decompositions (Sagar and Chockalingam 2004), and granulometry (Tay et al. 2005b, 2007).
