This electronic text provides students, instructors, and professionals in the hydrological sciences with the tools to pursue study and research using numerical methods. The text describes basic concepts, algorithms, and skills required for numerical computations and their applications and includes student exercises. The PDF format enables convenient local printing, extensive hyperlinking, and enhanced features such as downloadable figures, computer code, and animations.

• The authors describe the role of numerical methods in solving hydrological problems and the structure of this online educational resource.
  
  
• The 13 chapters in this book can be navigated through a fully hyperlinked table of contents and a subject index.
  
  
• A brief user's guide explains the book's many special features.
  

• Adobe Acrobat 6.0 or higher required to take full advantage of the PDFs.