Concise Hydrology

This is an introductory book on hydrology that covers the fundamental theories on hydrological cycle (water balance, atmospheric water, subsurface water, surface water), precipitation analysis, evaporation and evapotranspiration processes, infiltration, ground water movement, hydrograph analysis, rainfall runoff modelling (unit hydrograph), hydrological flow routing, measurements and data collection, hydrological statistics and hydrological design.

You can download the book for free via the link below.