The purpose of this book is twofold. First, to present the approach to and understanding of hydrology. That approach is best designated as "Watershed Hydrology". Second, to provide students of hydrology with a wildland-oriented text with a focus on storage. The author's understanding is one born of courses in both engineering and ecological hydrology, by practicing field work and research, and through his consulting experience. He has seen engineers who have paid little attention to the natural world around them, and environmentalist protectionists who have paid little attention to the realities of water as a physical entity in the environment. His organisation is based on scientifically founded knowledge of the hydrologic environment in its natural state. This posture is essential in order to comprehend the interactions of natural hydrologic events and the impacts of our inadvertent and planned activities on that environment.
Generally this book is about the ecology of watershed hydrology. A watershed is a natural unit of land from which the surface, Subsurface and ground water runoff drain to a common outlet. Hydrology is the study of water in the natural environment; the study of the laws, principles, processes, quantity, and quality of water movement and storage. In this book, the emphasis is on wildlands. Watershed hydrology, then, is simply the study of the movement and storage of water on and in the context of the natural land until of the hydrosphere, the watershed.