Analyzing Drought Hazards under a Changing Climate for the Semi-Arid Central Gujarat Region, India

Present research is focused on assessing spatiotemporal variability of meteorological drought based on Standardized Precipitation Index (SPI), non-parametric trend tests, and identifying drought hazardous pockets in semi-arid central Gujarat region, India. The SPI method at six monthly time step indicating seasonal drought has been utilized to characterize peak drought events, duration, occurrence probability, and major drought years. The SPI-6 time series has been further analyzed with Mann-Kendall (MK) and Sen's slope (SEN) tests to understand significance and magnitude of trends. The monthly rainfall data were obtained from Indian Meteorological Department ( IMD) gridded data archive having 0.25 degrees resolution for the time period of 1951-2020. The study revealed major droughts occurred in 1951, 1968, 1972, 1974, 1987, 1991, 2002, and 2015. The IDW interpolation method in GIS-Environment was adopted for spatial distribution of major drought years, near to extreme drought categories, as well as trend analysis outcomes. Based on the average SPI-6 values, 1985-1987, 1991-1993, and 1999-2002 durations were observed to be crucial drought scenarios in which the year 1987 was most extreme with drought intensity up to -2.86 in the northwest pockets. The reclassify and weighted sum operations were employed on the raster maps of drought occurrence probability (%) and trend magnitude (SEN) of drought series to prepare drought hazard map (DHI). The central Gujarat region observed 30.45% and 10.48% area under severe and extreme hazards. The outcomes from current research will prove helpful in evaluating regional drought policies for sustainable management of water resources under a changing climate.