... 282 DIGITAL TERRAIN MODELING: PRINCIPLES AND METHODOLOGY Figure 13. 16 13. 5.1 Surface runoff simulation using Voronoi cells and IFD modeling Line-of-Sight: Point-to-Point Visibility The simplest ... 2004/10/22 — 16:37 — page 273 — #7 274 DIGITAL TERRAIN MODELING: PRINCIPLES AND METHODOLOGY 13. 3.2 Plan and Profile Curvatures Hengl et al (2003) regarded Equation (13. 23) as the Evens–Young method ... “tf1732_c 013 — 2004/10/22 — 16:37 — page 279 — #13 280 DIGITAL TERRAIN MODELING: PRINCIPLES AND METHODOLOGY (a) (b) 1–100 101–1,000 1,001–1,000 10,001–10,000 100,001–500,000 500,001–900,118 Figure 13. 14...