Drought Risk Assessment: A Case Study in Punjab, Pakistan
Drought Risk Assessment: A Case Study in Punjab, Pakistan
Muhammad Amin1, Aftab Ahmad Khan2, Abida Perveen1, Zareen Rauf1, Sher Shah Hassan2*, Muhammad Arif Goheer2 and Muhammad Ijaz2
ABSTRACT
Drought is a natural hazard spreading gradually and caused serious harm to nature. It is frequently known as a “crawling phenomenon” or “crawling Disaster” as it is a plodding physical process and its effects spatially varies. Misperception on drought and its features is common in defining policies and caused delays in its prevention (Gore, 2002). Pakistan is one the counties which is affected badly by drought. In near Past, Pakistan faced one of the worst drought span drought in 50 years from 1998 to 2003 which harshly affected socially and economically. The present study was conducted on dry land areas of Punjab-Pakistan. The satellite data for NDVI were acquired from MODIS product MOD13A2 for years from 1996 to 2015. For the same period the data of 12-Month SPI values, GPCC precipitation and CPC soil moisture were also used. In formulating Climatological drought year, the droughts of years 2000 and 2002 were categorized as moderate drought years for the area have Precipitation Anomaly of -37% and -31%, respectively whereas Precipitation Anomaly values of -11.5, -15.6, -10.2 and -16.2 were found in years 2003, 2004, 2006 and 2009, respectively and categorized as slight drought years. The coefficient of determination between NDVI and Precipitation is 0.69 whereas between NDVI and Soil Moisture is 0.68. To verify delineated drought years, the data of different NDVI ranges such as Barren land, Dense Vegetation and Sparse Vegetation were analyzed along with Precipitation and soil moisture for monthly, yearly and seasonal basis. In center of study area for year 2000, the spatial analysis of DEVNDVI showed that there were the mild drought conditions during the month of February and intense drought conditions in the months of March and April. During the months of May to July, the eastern and western boundaries of the study area showed the development of drought conditions and these conditions become more intense in June. From August to October, the drought also advances in towards North side. In months of November and December, the drought conditions disappeared in the selected areas. Similarly, the spatial analysis of VCI showed that there were minor drought circumstances in the center and southern sides for the month of February whereas drought conditions found more intense during months of March and April in center part of study area. The southern, eastern and western sides of boundaries showed advances in drought happening from May to July and declining in the month of June. Therefore, the drought intensity decreased relatively in the central part for the months from August to October but it was still active. But for the months of Nov-Dec the drought conditions become intensive again in the area. The results of SPI analysis revealed that Mianwali district experienced moderate dry conditions out of all the districts for year 2000 with SPI value of -1.16 whereas Jhang experienced extreme dry conditions in same year with SPI value of -1.54. It is recommended that the current study should be considered as baseline for delineation and forecasting of drought years in Pakistan.
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