Analysis of ENSO-based climate variability in modulating drought risks over western Rajasthan in India

作者：Ganguli Poulomi; Reddy M Janga^*

来源：Journal of Earth System Science, 2013, 122(1): 253-269.

DOI：10.1007/s12040-012-0247-x

• Droughts
• climate variability
• El Nino-Southern Oscillation (ENSO)
• multivariate ENSO index (MEI)
• copulas
• recurrence interval
• conditional probability

This paper investigates the role of El Nino-Southern Oscillation (ENSO)-based climate variability in modulating multivariate drought risks in the drought-prone region of Western Rajasthan in India. Droughts are multivariate phenomenon, often characterized by severity, duration and peak. By using multivariate ENSO index, annual drought events are partitioned into three climatic states - El Nino, La Nina and neutral phases. For multivariate probabilistic representation of drought characteristics, trivariate copulas are employed, which have the ability to preserve the dependence structure of drought variables under uncertain environment. The first copula model is developed without accounting the climate state information to obtain joint and conditional return periods of drought characteristics. Then, copula-based models are developed for each climate state to estimate the joint and conditional probabilities of drought characteristics under each ENSO state. Results of the study suggest that the inclusion of ENSO-based climate variability is helpful in knowing the associated drought risks, and useful for management of water resources in the region.

• 出版日期2013-2