Building on the foundation set by the best-selling first edition, this second edition provides students and professionals with a qualitative understanding of hydrologic processes. It introduces the methods for quantifying hydrologic parameters and processes that are essential for addressing worldwide concerns such as water contamination. Completely revised and updated, the authors pay special attention to the chapter on remote sensing and geographic information systems to reflect the rapid technology advances in these areas. They include increased coverage of biological and ecological factors and use dual units (SI and English) to facilitate international use.