Multivariate Standardized Drought Index: A parametric multi-index model

Zengchao Hao,Amir Aghakouchak

doi:10.1016/j.advwatres.2013.03.009

Zengchao Hao, Amir Aghakouchak

Open Access

https://doi.org/10.1016/j.advwatres.2013.03.009

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Abstract

Defining droughts based on a single variable/index (e.g., precipitation, soil moisture, or runoff) may not be sufficient for reliable risk assessment and decision-making. In this paper, a multivariate, multi-index drought-modeling approach is proposed using the concept of copulas. The proposed model, named Multivariate Standardized Drought Index (MSDI), probabilistically combines the Standardized Precipitation Index (SPI) and the Standardized Soil Moisture Index (SSI) for drought characterization. In other words, MSDI incorporates the meteorological and agricultural drought conditions for overall characterization of drought. In this study, the proposed MSDI is utilized to characterize the drought conditions over several Climate Divisions in California and North Carolina. The MSDI-based drought analyses are then compared with SPI and SSI. The results reveal that MSDI indicates the drought onset and termination based on the combination of SPI and SSI, with onset being dominated by SPI and drought persistence being more similar to SSI behavior. Overall, the proposed MSDI is shown to be a reasonable model for combining multiple indices probabilistically.

Highlights

Droughts are common climatic extremes that often spread across large spatial and time scales [27]
Precipitation and soil moisture data are processed to illustrate the application of the proposed Multivariate Standardized Drought Index (MSDI)
Precipitation and soil moisture data for the same period 1932–2009 were obtained from the Climate Prediction Center (CPC)

Summary

Introduction

Droughts are common climatic extremes that often spread across large spatial and time scales [27]. Droughts affect more people across the globe than any other climate extremes [45]. Droughts are categorized into four major classes: meteorological, agricultural, hydrological, and socio-economical [18]. Meteorological drought is identified by lack of precipitation as the main indicator, while agricultural drought is related to the total soil moisture deficit. Hydrological drought, on the other hand, is characterized by a shortage of streamflow, as well as ground-water supplies. Several indices have been developed for drought monitoring based on different variables, such as precipitation, soil moisture, and runoff [24]. Mckee et al [23] proposed the Standardized Precipitation Index (SPI) as a drought indicator for

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Conclusion