A Non-Stationary Based Approach to Understand the Propagation of Meteorological to Agricultural Droughts.

The agricultural drought significantly affects the socio-economic sectors in the agrarian country like India. Though there is a larger variability in the drought characteristics, the time to propagation from meteorological to agricultural drought is not investigated at regional scale in India. The Standardised Precipitation Evapotranspiration Index (SPEI), and Standardised Soil moisture Index (SSI) are computed incorporating large-scale climatic oscillations and regional hydro-meteorological variables. The time to propagation is calculated based on three different approaches. In addition, the internal characteristics of agricultural drought propagation is computed. The important findings from the study suggest that the time of propagation varies between 5 to 7 months for drought initiation, 9 to 15 months for drought peak, and 10 to 20 months for drought termination. The internal drought development and recover periods varies from 3.1 to 6 months. Over most of the area, the instantaneous drought development and recovery speed magnitude varies between 0.20 and 0.60. Lastly, it is observed that the exclusion of physical covariates leads to underestimation of agricultural drought propagation characteristics over India. The results of the current study can be used to guide future early warning and monitoring systems for agricultural drought as well as the study of agricultural drought at the regional level. [ABSTRACT FROM AUTHOR]