Spatio-temporal analysis of droughts in the semi-arid Pedda Vagu and Ookacheti Vagu watersheds, Mahabubnagar District, India

This paper presents spatio-temporal meteorological drought analysis of Pedda Vagu and Ookacheti Vagu watersheds of Mahabubnagar and Ranga Reddy Districts of Telangana state, South Central India. Rainfall anomaly index (RAI) and run analysis have been leveraged to assess drought characteristics at different stations in the basin. The study also presents the interpolation of RAI values using spline technique in a geographic information system (GIS) environment to map the spatial extent and variation of drought severity in different time steps. The study reveals that the occurrence, magnitude, and recurrence of drought varied among the stations in the basin during an observed time frame, i.e., 1986 to 2013. Significant variations in the occurrences of number of drought events are observed among the stations in the basin. The spline interpolated rainfall anomaly index maps illustrated that some regions experienced more severe drought while other regions were well-off. This uncertainty in rainfall essentially indicates that a finer scale of drought vulnerability assessment is highly necessary for better drought management practices. Furthermore, empirical relationships were developed between drought duration and magnitude to support decision-making during various agricultural practices and water management.