Overland Flow

Drawing together leading specialists from geomorphology, hydrology and agricultural engineering, "Overland Flow" provides a review across discipline boundaries of a topic important in both scientific and practical terms. The book has been written with the specific aim of promoting interaction between modellers, field workers and laboratory experimentalists. Overland flow on hillslopes is of two types: Horton overland flow, which occurs where rainfall intensity exceeds the surface infiltration rate; and saturation overland flow, where water is forced to the surface or remains on it as a result of underlying saturation. Horton overland flow is widespread in arid and semi-arid landscapes, where it has mainly been investigated by geomorphologists, and on agricultural lands, upon which agricultural engineers/hydrologists have focused their concern. Thus, the two strands of research have proceeded more or less separately. Much of the research in both communities has been driven by the need to understand the causes and effects of soil erosion. During the past 15 years, the models used have changed fundamentally from empirical black-box models to process-based white-box types, whose integrity depends on an understanding of the hydraulics and erosion mechanics of overland flow. Field experiments, laboratory experiments and work through mathematical models have all been applied to the study of the topic. This book encompasses all three approaches in an attempt to bring together the best of current thinking. "Overland Flow" is thus for geomorphologists and agricultural engineers/hydrologists concerned with a topic central to understanding soil erosion and hillslope processes in natural environments and on cultivated land, or with the practical needs of agricultural land management. This book is intended for geomorphologists, hydrologists, engineers in forestry and agriculture, hydrological and hydraulic engineers.