Faculty Publications
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Item Assessment of meteorological drought return periods over a temporal rainfall change(Springer Science and Business Media Deutschland GmbH, 2021) Datta, R.; Pathak, A.A.; Dodamani, B.M.Investigation of the rainfall homogeneity along with bivariate frequency analysis of drought considering change points in long-term annual precipitation series has been carried out in this study. Nonparametric Pettitt’s test was applied for detecting change points of annual precipitation series at different grid locations over the Ghataprabha River Basin. Depending on the results of change point analysis, we divided the entire period of 1950–2013 into two subperiods: from 1950 to 1980 and 1981 to 2013. Characterization of meteorological drought is performed with the help of the Standardized Precipitation Index (SPI) at a time scale of three months for the period before the change point (1950–1980), after the change point (1981–2013) and for the entire period of 1950–2013. Three Archimedean copulas, namely Clayton, Gumbel–Houggard, and Frank, were tested for joint distribution modeling. The Akaike’s and Bayesian information criteria have been implemented for selecting the best copula; the Gumbel–Hougaard copula performed comparatively better for all three periods. Drought return periods were calculated using the joint distribution of drought characteristics. The study gives valuable insight into drought risk management on a regional scale. © Springer Nature Singapore Pte Ltd 2021.Item Comparison of Meteorological Drought Indices for Different Climatic Regions of an Indian River Basin(Korean Meteorological Society komes@komes.or.kr, 2020) Pathak, A.A.; Dodamani, B.M.Droughts being a regional phenomenon has a vicious impact on agricultural production as well as on the socioeconomic status of an area. Meteorological drought is not only the result of rainfall deficit but also influenced by temperature in the form of evapotranspiration. There are several indices that could assess meteorological drought. Because of the complex phenomenon underling in the interaction between climatic, hydrological and ecological variables hampers to ascertain the suitability of a drought index to a particular region. The present work aims to compare different meteorological drought indices for a given climatic condition at the regional level. The Standardized Precipitation Index (SPI), Reconnaissance Drought Index (RDI) and Standardized Precipitation Evapotranspiration Index (SPEI) were employed to study the variation of drought characteristics calculated from these indices. The study was implemented in the Ghataprabha river basin, which is one of the potential lands for agriculture in the basin of river Krishna. The study area possesses negative trends in rainfall and significant increasing trends in the temperature when tested with the Mann-Kendell trend test. Several drought events were observed through SPI, RDI, and SPEI over the basin. SPEI identified the highest number of drought events with high duration and severe intensity as compared to SPI and RDI. The alike performance was noticed between RDI and SPI whereas SPEI does not harmonize with them at any timescale of the study period. The study recommends to consider RDI and SPI in the humid (subhumid) region and SPEI at the semiarid (arid) region to assess the impact of drought effectively. The study also suggests to use an appropriate drought index for analysis of drought, which could lead to an adequate preparedness for the future drought hazards. © 2019, Korean Meteorological Society and Springer Nature B.V.