CR prepress abstract  -  DOI:

Historical analysis (1981-2017) of droughts severity and magnitude over a predominant arid region – Pakistan

Saadia Hina*, Farhan Saleem


ABSTRACT: Droughts are one of the multifaceted meteorological disasters affecting agriculture, livestock and water resources worldwide. The region of Pakistan has semiarid climate system with a higher degree of inter-annual rainfall variability. This study evaluates the applicability and comparison of three drought indices (deciles index (DI), standardize precipitation index (SPI) and reconnaissance index (RDI)) in Pakistan. The monthly rainfall and temperature data (1981-2017) of 30 weather stations was used to analyze current status of drought occurrence in terms of severity and magnitude. A nonparametric Mann-Kendall test and Sen’s slope estimates also applied on drought indices data to determine the statistical significance and magnitude of the trend. DI index well captured the dry episodes in the region, as Baluchistan and Sindh provinces have been seen to be more susceptible to droughts. The indices of SPI and RDI are well correlated at 3 (r2=0.987), 6 (r2=0.993), 9 (r2=0.992) and 12 (r2=0.985) month timescales. The province-wise analysis revealed the most numbers of drought years during 3-month timescale and least number of drought years during 12-month timescale. Overall, a linearly increasing trend of SPI and RDI index (towards wetness) has been observed, whereas the province-wise analysis showed statistically significant trend at 95% confidence level for Khyber Pakhtunkhwa (KPK), Punjab and Sindh in long-term droughts analysis. Moreover, analysis of historical drought years and their intensity have been investigated and compared with the recent long episode of drought (1999–2002). The analysis of historic drought events highlights the challenging nature of drought management in Pakistan. The outcomes of this study would help water resources managers to investigate drought response measures for drought preparedness in the country.