Stepped channel designs have been used for more than 3,500 years. A significant number of dams were built with overflow stepped spillways during the nineteenth and early twentieth centuries, before the design technique became outdated with the progresses in hydraulic jump stilling basin design. Recent advances in technology (e.g. RCC, polymer-coated gabion wire) have triggered a regain in interest for the stepped design, although much expertise had been lost in the last eighty years. The steps increase significantly the rate of energy dissipation taking place along the chute and reduce the size of the required downstream energy dissipation basin. Stepped cascades are used also in water treatment plants to enhance the air-water transfer of atmospheric gases (e.g. oxygen, nitrogen) and of volatile organic components (VOC).
This book presents the state-of-the-art in stepped channel hydraulics. It is based upon the research expertise of the writer, his professional experience as an expert-consultant, and his experience in teaching stepped spillway hydraulics to undergraduate students, postgraduate research students and professionals since 1982. Results from more than forty-five laboratory studies and four prototype investigations were reanalyzed and compared, enabling the book to provide a new understanding of stepped channel hydraulics, aimed at both the research and professional communities.