A COMPARATIVE ASSESSMENT OF AGGREGATION TECHNIQUES AND SENSITIVITY ANALYSIS FOR DROUGHT VULNERABILITY AND RISK ASSESSMENT IN INDIA

Abstract:

Long term drought management necessitates proper assessment and characterization of drought hazard, vulnerability and risk. This is particularly important for an agriculture-dependent, highly-populated developing country such as India. This study presents high-resolution drought vulnerability mapping in India using multiple aggregation techniques and reliable drought vulnerability indicators. For drought hazard assessment, we use the Multivariate Standardized Drought Index (MSDI) that considers simultaneous deficits in precipitation and soil moisture. Finally, the hazard and vulnerability information is combined to arrive at the drought risk maps for the country. Regions of Rajasthan, Uttar Pradesh, Orissa, Chattisgarh, Tamil Nadu, Karnataka, West Bengal and North-eastern India are found to fall under severe hazard category. From the drought vulnerability assessment analysis that compares subjective, objective and comprehensive aggregation techniques, it is found that a combination of Analytic Hierarchical Process (AHP) and Entropy approach, and the TOPSIS method perform better as compared to other methods in terms of consistency as well as rank reversibility. Bivariate cloropleth drought risk map reveals that the regions of Punjab, Haryana, Uttar Pradesh, Coastal Andhra Pradesh and Tamil Nadu are subjected to hazard-driven risk. On the other hand, drought risk in Rajasthan, Central India, Orissa, and Vidharbha are mostly vulnerability-driven. Parts of Western Rajasthan, Marathwada, Vidharbha, North-east India, West Bengal and Chattisgarh are under severe drought risk due to a combined effects of hazard and vulnerability. A sensitivity analysis based on map removal sensitivity technique shows that irrigation index, water body fraction, and groundwater availability are the most significant parameters for assessing drought vulnerability in India. The comprehensive drought risk maps prepared in this study serve as useful tools in building drought resilience.