Book excerpt: Hillslopes occupy most the landscape. Studies of process mechanisms and rates have become sufficiently numerous to allow a systematic study of slopes. Only by making a synthesis of quantitative process studies and relating them to the development of slope forms can the shape of the landscape be understood and the separate effects of lithology and climate assessed. In the introductory part of this book, the choice of appropriate system and scale is discussed, and models for uplift and erosion evaluated. Attention is thus focused on the dynamic equilibrium of the slope profile and its erosional development over time. Part I then examines the forces encouraging hillslope movement and the resistances opposing movement. Part 2 considers processes of rock instability, soil instability, wash, solution and soil creep. Each is discussed in terms of its mechanism and rate of operation, and the slope provides it produces. Part 3 outlines how this systematic approach may be applied to areas of different climate and the extent to which there is an assemblage of processes characteristic of each area. In part 4, the process evidence and models are combined into theoretical sequences of slope profile development, and the effect of contour curvature in modifying these profiles on spurts and in hollows is examined.