A comprehensive introduction to entropy and its various applications in the hydrologic sciences. Entropy Theory in Hydrologic Science and Engineering deals with basic concepts of entropy theory from a hydrologic engineering perspective. The application of these concepts to a range of hydrologic engineering problems is discussed in detail. This unique resource is divided into subsections--preliminaries, rainfall, subsurface flow, surface flow, and environmental considerations. It covers all phases of the hydrologic system and reviews the applications of entropy theory across the entire spectrum of hydrologic sciences. Coverage includes: Morphological analysis Evaluation and design of sampling and measurement networks Precipitation variability Rainfall frequency distributions Assessment of potential water resources availability Evaluation of precipitation forecasting schemes Infiltration Soil moisture Groundwater flow Rainfall-runoff modeling Hydrologic frequency analysis Steamflow simulation Long-term streamflow forecasting Flood forecasting Bivariate analysis River regime classification Sediment yield