Drought Impact and Recovery: A Case Study of the Rainfed Area of Punjab, Pakistan

This study aims to assess the impact of and recovery from the 2009-10 mild drought that struck the rainfed region of Punjab, Pakistan (Fig 1). The change in vegetation cover has been used as an indicator to measure the severity of the drought. Satellite data based spectral Enhanced Vegetation Index (EVI) was chosen to represent the vegetation cover and the data products from Moderate Resolution Imaging Spectroradiometer (MODIS) were used. The base years (non-drought years) selected were 2006 - 2008. Mean EVI of base years were calculated at pixel level and the change in vegetation from the mean was taken as an indicator of drought impact. The negative change indicated the drought affected pixels as the negative values in each pixel show a decrease in vegetation, whereas, the positive values show the increase in vegetation as compared to the base years. The methodology can be viewed in Fig 2. Furthermore, the change in vegetation from drought year was also calculated for recovery year (2010) to ascertain the extent of drought recovery in the post drought period. The results indicate that the drought was at its peak during the month of December, 2009 after which its intensity started receding. Fig 3 shows the mean EVI of the base years, the vegetation change in the drought year from mean, and the vegetation recovery in the post drought year. Though the entire study area can be seen affected by the drought, it is also noticeable that a severe drought struck the northern, north-western, and mid-western parts of the region. In addition, the drought recovery map indicates that the northern part of the rainfed Punjab recovered the most in the post drought year. The results of the analysis reveal that 97% of the vegetated area of Rawalpindi was impaired making it the most drought affected district. On the contrary, district Dera Ghazi Khan turned out to be the most resilient district with approximately 54% of its vegetation affected by this drought. The percentage of area affected by drought can be seen in Fig 4.