Spatiotemporal Variability of Short-Term Meteorological Drought for Semi-arid North Gujarat Region, India

Abstract

The present research analyzed spatial and temporal variability of short-term meteorological drought using Standardized Precipitation Index (SPI) and non-parametric trend tests for the semi-arid north Gujarat region, India. The SPI-6 indicating meteorological drought has been thoroughly examined considering drought characteristics such as intensity, duration, recurrence probability, and major drought years. The SPI-6 analysis along with non-parametric trend tests such as Mann-Kendall (MK) and Modified Mann-Kendall (MMK) for trend significance, Sen’s slope (SEN) and Linear Regression (LR) for trend magnitude and Lanzante’s test (LNZ) for change point detection were performed on Indian Meteorological Department (IMD) gridded rainfall data having time span 1951–2020 years. The analysis revealed major drought events for the years 1968, 1974, 1987, 1999, 2002, and recently in 2018 which were spatially distributed for the entire region using the IDW interpolation method in GIS-Environment. Based on the average SPI-6 values over the entire region, 1985–1987 and 1999–2002 time periods were observed to be severely dry spells in which 1987 was the extreme drought with intensity up to -4.24 in southern parts. The recurrence probability of extreme droughts was found to be highest (1 in 18 years) in northern and central parts. The trend analysis of SPI-6 values highlighted negative trends in about 17% of the grid points indicating drought-prone areas whereas about 83% of the grid points revealed positive trends indicating increasing wet spells. From the change point detection, significant changes in drought were observed for the year 2002 in most grid points. Present research outcomes will be helpful in crafting regional drought policies for the sustainable management of water resources in a changing climate.