This fascinating work is divided into two main sections. Part I reviews the basic principles of water movement in channels and the mass balance approach common to most models. It also covers the practical usefulness, model peer review, and guidance on model selection and calibration. Part II discusses flow simulation and prediction of time of travel, dye tracing and mixing, heat balance and temperature modeling, and reaeration and volatilization. This interesting, easy-to-read volume includes comprehensive reviews for the use of fluorescent water tracing dyes, longitudinal dispersion, evaporation and wind speed functions, prediction of saturation concentrations of dissolved oxygen, and reaeration coefficients. This book furnishes the reader with appendices which provide a synopsis of available computer models and gives a comprehensive listing of methods used to measure flow rates in rivers, tributaries, and pipes and channels introducing wastewaters into streams. This volume is a valuable, indispensable reference for all researchers, instructors, students in advanced environmental modeling courses, and practicing engineers.