Spatial and temporal variation of rainfall and drought in Khyber Pakhtunkhwa Province of Pakistan during 1971-2015

High rainfall variation creates problems of floods and droughts in any region of the world. This study focuses on spatial rainfall variability and drought assessment in Khyber Pakhtunkhwa province of Pakistan using Standardized Precipitation Index (SPI). Various indices like standard deviation, skewness, and kurtosis were calculated from annual rainfall of 15 meteorological stations during period of 1971-2015. Mann-Kendall technique was applied to both 1-month and 12-month SPIs for trend detection. All stations showed a positive skewness except Balakot. The highest variability was found in Parachinar and Balakot. The results of 12-month SPI showed two distinct dry periods, i.e., 1984 to 1989 and 1998 to 2002. Mann-Kendall trend test for 1-month SPI reveals more significant positive trend in Parachinar and there was variation in the results of other met-stations. In almost all the met-stations, December was found the driest month as the p values were found negative except in Parachinar. Additionally, the result of 12-month SPI indicated more significant positive trend in Parachinar, whereas more significant negative trend in Balakot met-stations has been recorded.