While occurrences of water bodies (rivers and canals;reservoirs, tanks and ponds; beels, oxbow lakes and derelict water; and brackish water) across the country depend upon physiographic settings and rainfall conditions, the recharging of the water
bodies depends mostly on rainfall which is a highly variable parameter. In this study fluctuation characteristics of annual, seasonal and monsoon monthly rainfall have been reported for 15 physiographic divisions and 49 subdivisions/provinces using longest available instrumental rainfall records from well-spread 316 raingauge stations. For the period 1901-2006, with data available for all the selected raingauges, the area-averaged
rainfall series has been prepared from simple arithmetic mean of the gauges in the particular region.