SPATIAL AND TEMPORAL DROUGHT HAZARD, VULNERABILITY AND RISK IN THE GODAVARI BASIN, INDIA

Abstract

India cannot be deemed as a country that is immune to droughts. Drought occurrences have been persistent in the country for a significant period of time. Its prediction and future risk analysis are quite difficult but manageable. There is not a single method that can tell everything as a whole. So, this work focuses on assessing spatiotemporal drought hazard and vulnerability over the Godavari basin using the precipitation, temperature and soil moisture data of a 40-year period (1980-2020). This will help us understand the factors affecting drought frequency, magnitude, and duration. This data is collected from agencies like the IMD, MERRA-2, NASA-SEDAC etc. The SPI, SPEI, MSDI and RDI drought indices are used to carry out this drought analysis. These indices were calculated on a 12-month time scale to understand the spatial and temporal drought variations and their hazards. Several heatmaps were prepared to identify the dry spells of the region during the study period. This work suggests a good positive correlation among all the drought indices. It also shows that drought magnitude and duration are positively correlated, while intensity shows a negative correlation with other drought characteristics. The DHI is calculated by applying a weight and rating approach to the probability of occurrence of different categories of droughts. Weights are assigned as per the severity of the drought, while ratings are assigned from 1 to 4 to the probability of occurrence of each drought class. The vulnerability analysis was performated by aggregation of various vulnerability factors like population density, female-to-male ratio, irrigation index etc., for the assessment of drought risk in the Godavari basin to identify the most drought-prone areas of the region. The findings reveal that DHI values based on the SPEI index indicate notable drought hazards in the middle and south-east regions of the basin, while SPI suggests a higher drought risk in the western part of the basin. Mirroring the drought hazard findings, DRI based on SPEI indicates increased drought risk in the mid and south-east regions. Districts such as Ahmednagar and Bid, in western region, display lower DVI values. Notably, the southeast regions of the basin exhibit higher DVI values, indicating increased vulnerability to drought. The results of this study provide valuable insights for decision-making and future drought management strategies in the study area, facilitating more effective planning and interventions by the government and relevant stakeholders.