Multivariate Probabilistic Dependence Analysis of Projected Future Drought Characteristic over India

Warming of climate has not only altered the nature of floods but of droughts also. India faces drought event covering more than half of its area almost every four years. Understanding the nature of changing drought characteristics under different warming scenario remains a challenge for researchers and policy makers in India. Previously, a few studies have attempted to investigate the droughts characteristics using projected data obtained from different climate models over India. However, these studies failed to quantify the uncertainty in the drought projection over different river basins of India. In this study, we analyse the uncertainty in various drought characteristics for near future (NF; 2020-2049), and far future (FF; 2070-2099) and compared with the historical baseline period (1970-1999). Uncertainty of copula based joint return period (JRPs) over various periods in future were also studied. Existence of a very high uncertainty for different drought characteristics such as severity, duration and intensity were found for most of the river basins. Results of Joint Return Period analysis revealed a high probability of co-occurrence of T5 and T10 characteristics together in the same year for most of the basins. The frequency of occurrence of any two drought characteristics exceeding their respective T50 return values together in the same year were found to decrease significantly in future with respect to the historical period. For FF, likeliness of co-occurrence of exceedance of T5, T10 and T50 return values of different characteristics in the same year have been found to be less as compared to NF.