Drought is considered to be a normal feature of climate especially in tropical countries where occurrence of periods of dry weather during rainy season is common. Virtually droughts can occur in all climates and they can also be witnessed when the air temperatures are higher than the normal for a longer period that increases both evaporation and water deficit. The first chapter deals with the introduction to the topic, historical evidences of drought and famines in India. The definition of droughts, criteria for classification of droughts, drought indices based on rainfall, climate...