Hydraulics is a branch of scientific and engineering discipline that deals with the mechanical properties of fluids, mainly water. It is widely applied in many civil and environmental engineering systems (water resources management, flood defence, harbour and port, bridge, building, environment protection, hydropower, irrigation, ecosystem, etc). This is an introductory book on hydraulics and written for undergraduate students in civil and environmental engineering, environmental science and geography. The aim of this book is to provide a concise and comprehensive coverage of hydraulics that is easy to access through the Internet