Drought Risk Assessment Under Changing Climate for Semi-Arid Central-East Region of Gujarat, India

Present research developed drought risk index (DRI) under changing climate by analyzing multiple indicators of drought hazards (DHI) and drought vulnerability (DVI) for semi-arid central-east region of Gujarat, India. The daily gridded rainfall data of 1951 to 2020 time period having 0.25° spatial resolution were collected from Indian Meteorological Department (IMD) to analyze drought characteristics. The Standardized Precipitation Index (SPI) method at 6 monthly time step indicating seasonal drought was utilized to assess peak drought years and major historical drought events. DHI was assessed by considering near, moderate, severe and extreme drought events along with spatiotemporal variability of drought trend magnitude obtained from Sen’s slope method which addressed the research gap of analyzing drought hazards under changing climate. DVI was analyzed by considering total water availability, population density, land use types, irrigated area and regional slope. Current study identified peak drought events for 1961, 1965, 1974, 2002 and 2015 years with 1985 to 1987 time period being the longest drought duration for major parts of the study region. About 30 % of the grid points showed negative trend magnitude indicating increasing drought intensity in the near future. The IDW interpolation, reclassify and weighted sum tools were employed in GIS environment to prepare DHI, DVI and DRI raster maps which were categorized in five classes of low, medium, high, severe and extreme. The central-east region of Gujarat observed approximately 47, 60 and 37 percentage area under severe to extreme classes for DHI, DVI and DRI respectively which should be prioritized for sustainable water resources management under changing climate.