Hydrology has gained a great significance in recent decades with the expansion of the water resources development studies that are an important component of man’s efforts in controlling the environment. Although information about the water on the earth is being collected for several centuries, only recently this information is transformed into a science and put into use in engineering studies. Hydrology, as a science that deals with the distribution, motion and properties of the water on the earth, plays an important part in thcse studies. Hydrologic studies are given an impetus by the rapid growth of the population, agriculture and industry.

In the book, hydrologic events are analyzed by a system approach, following various components of the hydrologic cycle. It is attempted to introduce the student to the recent developments in hydrologic measurements, and the applications of the methods of the system analysis and statistics. A balance is tried to be achieved between various deterministic and probabilistic approaches so that the student can have an idea about the possible methods of treatment of hydrologic problems. Solved problems are added at the end of each chapter to illustrate the use of the methods described in the text. An extensive list of references is given at the end of the book.