Assessment of Meteorological Drought using Standard Precipitation Index (SPI) in Western Maharashtra, India

Abstract

The crop production in rainy season in rainfed areas is dependent on vagaries of monsoon and is adversely influenced. The knowledge of different rainfall characteristics such as onset and withdrawal of monsoon, dry spell and drought would enable the optimal crop planning and implementation of protective irrigation strategies, thus mitigating the adverse impact of uncertainties of rainfall. The assessment of drought is one of the most important steps in risk management of drought analysis. The basis of drought indices is often based on measuring the deviation of precipitation values from long-term mean, during a specific period of time. The standard precipitation index (SPI) can be used for indicating the associated temporal and spatial variations. The aim of this research is the assessment of the characteristics such as intensity of meteorological drought using SPI with 12 months time scales in Western Maharashtra, India. The index has been computed in with 12 months time scales for 105 stations with 30 years record period in the study area and evaluated for the recent drought during 1983-2012. The results indicate that the rainfall pattern of Western Maharashtra exhibits non-uniform, irregular and erratic pattern of rainfall, as evidenced from SPI values. The meteorological drought shifted one step towards severity of drought condition for the time scales (month 1-12) i.e. from extremely wet to very wet; very wet to moderately wet; moderately wet to near normal; near normal to moderately dry; moderately dry to severely dry and severely dry to extremely dry condition.