Records of Monsoon Variability in the Rain-shadow Zone of Western Maharashtra, Based on Multi-proxy Studies of Deposits in Two Historical Tanks

Global climate change is the predominant socio-economic, environmental and political issue confronting the mankind in the 21st century. The humanity in future is likely to depend upon the realistic assessment of the present climate and reasonably accurate prediction of the future climate change. This requires better understanding of the dominant characteristics of past climates. Lakes and tanks located in the semi-arid and arid regions are particularly suitable for palaeoclimatic studies, because of their high sensitivity to shifts in precipitation. The present study has been carried out using multi-proxies (e.g., textural, geochemical, mineral magnetic and charophytes studies) of sediments of two historical tanks namely, Bhatodi (~450 yrs old) and Mastani (~270 yrs old), from the rain-shadow zone of Western Maharashtra to understand the nature of monsoon variability in the catchment area of the tanks. The multi-proxy analyses of 4-5m thick sediment sections have revealed that with the exception of some minor sedimentary units in the middle, the lake sediments are by and large similar. This implies only short-term, subtle to modest changes in the rainfall and runoff conditions in the catchment area during the last 2-3cm. There is no evidence a major shift in monsoon rainfall conditions in the rain-shadow zone.