This monograph is a fundamental study of watershed erosion and runoff processes. It utilizes decades of soil erosion data to take a comprehensive and balanced approach in covering various watershed erosion processes. While there are many works on soil erosion and conservation, this book fills the gaps in previously published research by focusing more on mass movement, gully erosion, soil piping/tunnel erosion, and the spatial interactions of different erosion processes. Additionally, the book examines erosion processes in extreme rainfall events, something typically absent in short-term studies but discussed in detail here as the book draws on 60 years of research and observations, including 30 years of the author's own investigations of erosion under a wide range of rainfall conditions. The book is divided into 3 parts, and is intended for soil erosion researchers and practitioners, and postgraduate students studying soil erosion and water conservation.

Part 1 opens with a comprehensive and critical review of existing literature on soil erosion processes, discusses this book's place among existing literature, and examines the major erosion processes (rainwash, gully erosion, tunnel erosion, and mass movements) including their controlling factors and mechanisms. Part 2 explores the spatial interactions of these different erosion processes to provide a prerequisite for effective design of comprehensive soil erosion control measures in a watershed. Part 3 evaluates the relative significance of these erosion processes in sediment production, the effectiveness of comprehensive soil and water conservation programs, and the applications of watershed modelling in determining the impact of land-use changes on soil erosion and other ecological processes.

Tongxin Zhu is a Professor of Geography and Environment at University of Minnesota Duluth. He received his Ph.D. at the University of Toronto in 1998, and has published 5 papers in books and more than 40 papers in referred journals. His research interests focus on the geomorphic and hydrologic processes at plot, hillslope and watershed scales by integrating field and experimental studies with simulation modeling. His recent research includes assessing the susceptibility and erosion risk of mass movement, investigating the spatial variability of soil shear strength within the gully systems, and examining the interactions of water erosion, mass movement, tunnel formation and gully development at watershed scale. He teaches classes in physical geography, environment, and Geographic Information Systems (GIS).

Xiangzhou Xu is a full professor and Ph.D. supervisor at Dalian University of Technology (China). His research focuses on soil conservation and sustainable development. The Topography Meter developed by him opened a new way for tracking and measuring landslides. He is the principal investigator of over ten national, ministerial and provincial projects. He has also won two prizes of the Ministerial and Provincial-Level Science and Technology Awards as the first or third accomplisher. He is the first or corresponding author of over 50 journal articles, and first or co-author of three monographs. Two United States Patent and 20 Chinese invention patents filed by him has been granted.