This text provides a comprehensive treatment of GIS technology and its application to a range of hydrologic problems. It contains 16 chapters, written by leading scientists from around the globe, that provide an in-depth discussion of GIS applications. Hydrologic modelling is becoming increasingly global, in terms of both spatial scale and depth of treatment. This globalization of hydrology is placing new and greater demands for data, and more sophisticated techniques for managing and processing them. It is now possible to meet those demands through application of remote sensing and GIS technology.