Assessment of Meteorological Drought Over Andhra Pradesh Under Future Climate Change Scenarios
摘要
This study analyses the existence and persistence of meteorological drought in 6 districts of Andhra Pradesh using Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI). Observed gridded daily precipitation data of 0.25-degree resolution and temperature data of 1-degree resolution from Indian Meteorological Department for the period 1980 to 2015 were used for this purpose. Future conditions of drought (2020–2100) was predicted using future climate projections of precipitation and temperature using CORDEX data. To know the variations in drought events, analysis was performed for different time scales such as 3, 6, 9 and 12 months. The results reveal that the drought conditions existed in the past (drought affected years-1980, 1982, 1986, 1987, 1992, 1999, 2002, 2003, 2009 and 2011) and the same may continue in the future also according to the Representative Concentration Pathways (RCP) scenarios 4.5 and 8.5. More severe drought events were observed under RCP 8.5 scenario than RCP 4.5 scenario. Drought characteristics (duration, frequency and severity) based on Run theory have been performed and the results showed that the severity according to SPEI is more than that of SPI. Also, a greater number of moderate and severe drought events were identified in the analysis based on SPEI compared to that of SPI, clearly demonstrating the importance of considering temperature in the drought analysis along with rainfall. Findings of this study will be useful to identify the drought hotspots in the study area and the expected drought intensity in the future so that adaptive strategies could be devised.