Spatio-Temporal Analysis of Drought and Aridity in Gomti Basin

This study analyses the drought events for the Gomti basin in Uttar Pradesh (UP), India using the standardized precipitation index (SPI) at the spatial and temporal scales. Daily precipitation data for 14 districts in the Gomti basin for 41 years (1971–2011) were used to calculate the SPI for 1-month, 4-month, 6-month and 12-month time scales. Results for the 6-month (June–November) and 12-month time scales were similar and drought years were observed in 1972, 1979, 1987, 1993, 1994, 2002 and 2010. The 4-month SPI was analysed for the main monsoon months in the Gomti basin, i.e. from June to September. Results showed that significant drought occurred during the monsoon months of 1979, 1987, 1993, 2002, 2009 and 2010. For drought analysis at the spatial scale, the Kriging interpolation method available in ArcMap was used. The 12-month SPI showed that the frequency of severe and extreme drought was more in the upper regions of the basin during 1971–2000 whereas drought frequency was more in the central and lower regions of the basin during 2001–2011. Further, the de Martonne aridity index was calculated for the period 1971–2007 and its correlation with the 1-month SPI for the period 1971–2007 was evaluated.