The increase in drought is caused by many factors: shortfalls in precipitation; earlier snow melt; a shift away from light and moderate rains towards short, heavy precipitation events; and increased evaporation from soil and vegetation due to higher atmospheric temperatures, all of which have been driven at least in part by climate changes.
climatological cause of a drought is disturbance in water cycle and water flow...the lowering of ground water , the drying up of water bodies due to heavy heat is also a great cause. So basically higher and hotter summers are main cause cause of droughts and are caused by human activities
