Environmental Science is one of the most important areas of research and study in present time and its application in every aspect of life has also increased . Keeping this in view, almost all Indian Universities have introduced it as a compulsory course. This book is intended to suit the needs of graduate and postgraduate students pursuing environmental studies. To save the natural environment, a good and effective understanding of environmental science is needed. Environmental science is a term that has been widely used in recent years and its manifestations can range from environmental awareness learning through complex and expensive environmental study to operational research studies of environmental educations systems.