Spatio-temporal characteristics of precipitation and drought in Balochistan Province, Pakistan

Abstract

In this paper, spatial and temporal variability of drought in Balochistan has been investigated using 36 years (1975–2010) of monthly precipitation data recorded at 23 rain gauge stations in the study area. In order to detect and understand precipitation trend on drought severity, Mann–Kendall test is used. Standardized precipitation index is used to compute the severity of drought. Inverse distance weighted method has been used to illustrate the spatial and temporal aspects of drought with varying intensities. In addition, perception and understanding of the 215 farm households about drought are assessed following an in-depth field survey. The results reveal that farmers’ perception regarding climatic variability and drought are in line with the results obtained using the secondary climatic data and information. Mann–Kendall test results indicate that negative trends in precipitation are evident for both annual and seasonal scale for more than 70 % of the stations in Balochistan ranging from 137.2 to 283.4 mm over 36 years, which may affect the drought mitigation, local water resources management and agriculture decision making. Furthermore, frequency of severe and extreme droughts is higher in north-west, from central parts towards south, south-east and some coastal areas when analysed quarterly at 3-month winter season and annually for 12-month dry–wet periods. Central-eastern, south-western, southern and some isolated coastal areas in the south are more susceptible to severe droughts particularly during winter and dry–wet periods because of high variability in precipitation in these areas.