A Comparative Study on Regional Drought Characterization Using Estimated Drought Indices in Conjunction with Trend Analysis in Peninsular India

Abstract

AbstractThe objective of the present study is the characterization of drought conditions in two important peninsular states of India namely Tamil Nadu and Karnataka through assessment of meteorological drought indices namely drought index (DI), Palmer index (PI), and standardized precipitation index (SPI). For this, monthly and yearly data of precipitation and temperature have been considered for 110 years (1901–2010). Precipitation deficit conditions have been estimated and compared for both regions using annual rainfall classification thresholds. The annual variability of rainfall and associated trend were estimated using Mann-Kendall test and comparative analysis was done to assess the regional variation during the last 110 years. Comparative study on results implied that drought characterization using SPI may amply facilitate the standardization of threshold classification for severity and frequency that was good agreement with observed events. The application of trend detection framework resulted in the identification of significant trends in those districts which were reported to be drought prone regions. Study amply suggested that drought vulnerability in Tamil Nadu was relatively more than that of Karnataka region depending upon the number of dry and wet years in terms of SPI threshold values and areal extend within 110 years of study period however in terms of severity and number of occurrence, Karnataka was more vulnerable. Analysis based on droughts indices suggests that SPI is simple to evaluate and may relatively more meaningful and conclusive in terms of decision making for the study region if compared with other indices.KeywordsTrend analysisDroughtDrought characterizationDrought indicesStandard precipitation indexVulnerability map