Long-term (1870-2018) drought reconstruction in context of surface water security in India

Droughts in India affect food production, gross domestic product (GDP), livelihood, and socio-economic condition of a large population associated with agriculture. Recent drought (2015-2018) caused groundwater depletion and affected about one-fourth of the Indian population. However, it remains unclear if the drought of 2015-2018 was among the most severe droughts that occurred in India. Here we use a long-term (1870-2018) data to identify the top five (deadly) meteorological/hydrological droughts based on overall severity score in the last century and half period. Out of a total of 18 meteorological droughts, the deadly droughts occurred in 1899, 1876, 2000, 1918, and 1965. Similarly, the deadly hydrological droughts occurred in 1899, 2000, 1876, 1965, and 1918 during 1870-2018. All the five deadly droughts were associated with the positive phase of El Nino Southern Oscillations (ENSO). Results show that the relationship between ENSO and monsoon (June to September) precipitation in India has weakened while the role of Indian and Atlantic Oceans have strengthened during the recent decades. Notwithstanding the longest (41 months) duration, the 2015-2018 drought did not feature among the deadly droughts. The 2015-2018 drought affected surface (reservoir storage) and groundwater availability in both southern and northern parts of India and was linked to El-Nino and Indian Ocean Dipole. Droughts and rapidly declining groundwater together can pose serious challenges to water security in India.