Analyzing the Drought Events using Univariate and Multivariate Drought Indices for Punjab, Pakistan

Abstract

Now a day's humanities are facing environmental challenges due to natural dis- asters. Drought is one of the big disaster it occurs naturally in all climatic regions such as high as well as low precipitation areas. The e ects of drought are both on society and natural environment and cause high economic, social and agricultural cost around the globe. Drought occurs due to de ciency or lack of precipitation over a long period, usually a season or more. In Pakistan, like many other hazards several adverse impacts of drought hazard are continue. However, on the other hand the in- teraction of humans with the environment often reduces natural resilience. Detection and measurement of drought in the early stages helps the policy makers to control the e ects of drought employing the drought mitigation policies. Therefore, we in- vestigate spatio-temporal variability in droughts of ten meteorological station of the Punjab province. Monthly time series data for thirty- ve years during (1980􀀀2014) is used. Meteorological variables i.e. average monthly Precipitation (P), minimum, maximum and average Temperature (T) has been analyzed for drought monitoring and classi cation. Standardize Precipitation Index (SPI), Standardize Precipitation Evapotranspiration Index (SPEI) and Multivariate Standardized Precipitation Index (MSPI) are utilized for drought de nition and classi cation . The index MSPI is based on the sets of SPI calculated from 3 to 48-time scale. Besides this, we pro- posed a multi-scaler and multi-variables drought assessment tool i.e. Multivariate Standardized Precipitation Evapotranspiration Index (MSPEI). The objective of this proposed index is to address the issue of multiple time scale using multiple variables. The proposed index is based on ve sets of SPEI time series calculated from scale-3 to scale-48. Comparative analysis has been performed between MSPI and proposed index using correlation, visualization, and droughts frequency classi cation.