• ●Bakhira Wildlife Sanctuary lies in Sant Kabir Nagar district, Uttar Pradesh, and was designated a Ramsar Site on 2 February 2022; it spans about 2,894 hectares.
• ●It is the largest natural floodplain wetland of eastern Uttar Pradesh - a perennial oxbow wetland formed by cut-off of the Rapti River, in the Ghaghara-Rapti alluvial system.
• ●Study by the Birbal Sahni Institute of Palaeosciences (BSIP), Lucknow, an autonomous institute of the Department of Science and Technology.
• ●Method: environmental magnetism - magnetic minerals in sediment used as a proxy for rainfall, erosion and sediment transport.
• ●Record: about 25,000 years, back to the Last Glacial Maximum, dated by seven AMS radiocarbon dates.
• ●Events captured: Last Glacial Maximum/Heinrich Stadial 1 (~25.3-18.1 ka), Bolling-Allerod (~15.3-12.8 ka), Younger Dryas (~12.8-11.1 ka), Holocene Climatic Optimum (~9.2-4 ka), late-Holocene droughts (~4-2 ka).
• ●Purpose: better Indian Summer Monsoon models and water-resource planning in the Central Ganga Plain.

Bakhira Wildlife Sanctuary, whose lake sediments were used to reconstruct past monsoon variability, is located in which state?