Use of meteorological data for identification of drought

Abstract

ABSTRACT Drought is called a creeping disaster because of the way it develops. It can be categorized as meteorological, hydrological, agriculture and socioeconomic drought. In the present study, meteorological data in terms of monthly rainfall for 45 years (from 1971 to 2016) were used for identification of drought in Anantapur district of Andhra Pradesh in India. Different drought indices like percentage of departure (), percent of normal, decile and Standardized Precipitation Index (SPI) were derived. Percentage of departure ( is identified based on rate deviation of yearly precipitation from the long-term yearly mean precipitation. Percent of normal is obtained by dividing the precipitation by normal precipitation for the time being considered. It interprets the deficient of rainfall from wet season to dry season and vice versa as precipitation deviation from the normal annual precipitation. Decile is calculated by interpolation technique based on ranking given to the rainfall distribution. SPI values were generated based on gamma distribution of precipitation data. Compared with other indices, SPI shows better variation with small change in precipitation because of its statistical nature. Therefore, it is suggested that SPI as a stand-alone indicator needs to be interpreted with caution to assess the intensity of drought.