Tripathi, S., Thakur, B., Sharma, A., Phartiyal, B., Basumatary, S. K., Ghosh, R., ... & Bose, T. (2023). Modern biotic and abiotic analogues from the surface soil of Ganga-Ghaghara-Gandak interfluves of the Central Ganga Plain (CGP), India: Implications for the palaeoecological reconstructions. Catena, 224, 106975.

      The distinct topographical and geographical features of the Indian subcontinent provide varying climatic zones together with diverse vegetation types governed by the southwest and the northeast monsoon, depending upon the season. These monsoonal winds exhibit a rich variety of natural variations on different timescales ranging across sub-seasonal/intra-seasonal, interannual (year-to-year), multi-decadal and centennial timescales, which are evident from instrumental records and paleoclimate reconstructions, commonly known as monsoon variability. The frequency of extreme Indian summer monsoon (ISM) events has increased in recent decades, and there is significant spatial heterogeneity in the occurrence of extreme events. Moreover, the duration and intensity of ISM have altered during the past few years and is unpredictable, causing tremendous agricultural and economic loss. Future climate modelling requires rigorous and accurate palaeoclimatic data, which is yet to be generated, especially from the Ganga Plain (GP) and Core Monsoon Zone (CMZ), mainly comprising Madhya Pradesh, Maharashtra and Chhattisgarh states.

      To fill these information gaps in regard to ISM, the Quaternary Lake Drilling Project (QLDP) project aims to reconstruct the monsoon-driven climatic history of the terrestrial environment in the aforementioned regions to study major impacts on society.

      Lakes are considerably the best recorders of climate variability on terrestrial ecosystems as sediments accumulated from the surrounding environment and microorganisms produced within provide high-resolution histories of local environmental conditions, lake water chemistry, temperature and lake productivity in the past. A modern analogue of biotic and abiotic records from the

surface samples procured in and around the lake offers a quantifiable interpretation of past climate from the sedimentary archives of the lake. Additionally, generating tree ring width and isotope datasets can reconstruct climatic parameters with the annual resolution, pushing calibration periods further from instrumental observations. Further, Species distribution models (SDMs) identify species ecological niches as geographic space, which, in combination with species distributions in past and present as mapped in QLDP, will provide future projections of vegetation dynamics under the anticipated global warming and climate change scenarios.

The QLDP project has the following objectives:

  • To reconstruct the palaeo-climate and -hydroclimate variability during the late Quaternary using multi-proxy records and spatiotemporal mapping of abrupt and extreme climate events
  • To access chronological lag and disparity in long-term records and ascertain the causal mechanisms of climate vs. vegetation
  • To study climate-culture interaction in this region and social response variables
  • Palaeoclimate modelling
  • Creation of awareness and outreach for dissemination of knowledge to society

The project's first stage focuses on

  • Northwest India - Haryana, Rajasthan, western Uttar Pradesh
  • Central Ganga plains - central and western Uttar Pradesh, Bihar
  • Core monsoon zone - Maharashtra, Madhya Pradesh, Chhattisgarh