Late Holocene Monsoon Variability over Indian Peninsula as inferred from Palaeoflood Records

Abstract:

Palaeoflood records in bedrock gorges in southern India not only preserve information about centennial- to millennial-scale changes in the flood regime conditions, but also provide information on monsoon variability and extreme climatic events. During the last two decades, slackwater flood deposits of some Indian Peninsula rivers have been investigated to derive information about extreme hydrologic events and the climate variability during the late Holocene. Although there are inter-basin differences in the flood chronologies, regional histories show a number of similarities. Three main observations can be made on the basis of the synthesis of the available palaeoflood data from eight Peninsular Rivers. First, the palaeoflood records generally span a time period of 1-2 millennia, Second, the period between ca. 14^th and 19^th century CE, coinciding with the Little Ice Age, was marked by a sharp decline in the frequency of high-magnitude floods on all the rivers. Third, the post-1950 floods were observed to be the largest at least during the last several hundred years. The last observation is also supported by analysis of gauge data.