Understanding drought dynamics and variability over Bundelkhand region

Abstract: This study provides an evaluation of the past, present, and future spatiotemporal variability of droughts in the Bundelkhand region of central India. The assessment has been made by analyzing the existing (1951–2018) drought dynamics with gridded observational and reanalysis datasets. The future projection is presented using a multi-model ensemble from 21 simulations of regional climate model over CORDEX South-Asia domain under the highest carbon concentration, i.e., RCP8.5 emission scenario. The Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) indices are used for short and long-term monitoring of droughts. Spatiotemporal statistical analysis is performed to examine the relationship between drought indices, i.e., SPI, SPEI and driving parameters such as temperature, precipitation, etc. It is noticed that the frequency of drought has increased since the beginning of the 21st century. In particular, the northern part of the Bundelkhand region is more vulnerable to drought due to overall less precipitation and more temperature. The composite analysis of drought year indicates that moisture-laden wind from the Arabian Sea branch generally weakened in monsoon season. Teleconnections of drought over Bundelkhand region reveal that nearly 40% of the droughts are linked to El-Nino events that have become stronger in recent decades. The model ensemble realistically represents the regional climate reasonably well over the region. The projected change in near future drought shows more frequent events using both SPI and SPEI indices that are also detected in the observational analysis. Research Highlights: The Northern region of Bundelkhand is more prone to drought due to high temperature and low precipitation.The region receives most of its precipitation from Arabian Sea branch of monsoon winds that generally weakened in drought composite years.About 40% of drought variability is teleconnected with El–Nino years that has become more stronger in recent decadesThe ensemble of RCM simulations over CORDEX South–Asian domain indicates that the drought events are projected to be more frequent in near future.