This handbook has been published especially for the students and teachers/professors who are interested to increase their knowledge on hydrology. This is exactly the lecture note. This book consists of seven different units they are: Basic terminologies and concepts on hydrology (Unit-1), Atmosphere and hydro-logical cycles (Unit-2), Measurement of Precipitation (Unit-3), Evaporation and evapo-transpiration (Unit-4), Recharge and discharge of ground water (UNIT-6) and Runoff (Unit-7). Obviously, students can increase their marks in examination with the help of this handbook because this is a complete package on hydrology. This book is particularly important for engineering /forestry/geology/environmental science/NRM related students.Please enjoy this book and not forget to give the meaningful comments.