Palaeoflood Record of High-Magnitude Events during Historical Time in the Sabarmati River, Gujarat

We report the occurrence of large floods in the Sabarmati River Basin during cal AD 1400-1440. Slackwater palaeoflood deposits have been preserved in the highly dissected ravines along the middle reaches of the river, wherein 5-6 discrete flood events have been identified. The minimum discharge that emplaced the highest deposit has been estimated as ∼15,680 m³s^-1 and is higher than that recorded (3050 m³s^-1) during the recent 2006 flood. The timing of these high-magnitude flood events in the Sabarmati and adjacent river basins suggests that extreme hydrological events have occurred in response to excess monsoon periods and are largely controlled by the regional climatic conditions. Moreover, these flood events are seen to be broadly synchronous in the alluvial river basins of Gujarat across climatic zones, but are at variance in pattern from the records of the bedrock peninsular rivers.