UC Irvine

In the study, we analyzed variability of three univariate and multivariate drought indicators and yields of five of the largest rain-fed crops in Australia including wheat, broad beans, canola, lupins and barley. Using multivariate copulas, this study relates changes in climate variability to changes in crops production during 1980-2012. In the analysis period, the five chosen crops indicate a modest association with the selected drought indicators: Standardized Precipitation Index (SPI); Standardized Soil Moisture Index (SSI), and Multivariate Standardized Drought Index (MSDI). The latter combines precipitation and soil moisture and provides a measure of agro-meteorological drought. A model is developed to describe the relationship between drought and crop production using copulas. The model offers the likelihood of crop yield given an observed or predicted SPI, SSI or MSDI.