Standardized Drought Indices: A Novel Univariate and Multivariate Approach

Abstract

Summary As drought is among the natural hazards which affect people and economies world wide and often results in huge monetary losses, sophisticated methods for drought monitoring and decision making are needed. Many approaches to quantify drought severity have been developed during recent decades. However, most of these drought indices suffer from different shortcomings, account only for one or two driving factors which promote drought conditions and neglect their interdependences. We provide novel methodology for the calculation of (multivariate) drought indices, which combines the advantages of existing approaches and omits their disadvantages. It can be used flexibly in different applications to model different types of drought on the basis of user‐selected, drought relevant variables. The methodology benefits from the flexibility of vine copulas in modelling multivariate non‐Gaussian intervariable dependence structures. Based on a three‐variate data set, an exemplary agrometeorological drought index is developed. The data analysis illustrates and reasons the methodology described. A validation of the exemplary multivariate agrometeorological drought index against observed soybean yield affirms the validity and abilities of the methodology. A comparison with established drought indices shows the benefits of our multivariate approach.

Drought Characteristics and Its Response to the Global Climate Variability in the Yangtze River Basin, China

“…Furthermore, some updated Copula constructs such as vine Copula have been applied in research on drought. It has an exceptionally good result [68,69]. These studies give us an indicator to use in the new methods for our further research.…”

A novel spatially weighted accumulative procedure for regional drought monitoring

“…For these policies and drought monitoring, the characterization of drought is often measured by standardized procedures that are developed for improving the classification accuracy (Bezdan et al, 2019). Several studies provide various Standardized Drought Indices (SDI) (Erhardt and Czado, 2018), such as the Standardized Precipitation Index (SPI) (McKee et al, 1993), Reconnaissance Drought Index (RDI) (Tsakiris et al, 2007), Standardized Precipitation Evapotranspiration Index (SPEI) (Vicente-Serrano et al, 2010a, 2010b and Standardized Precipitation Temperature Index (SPTI) (Ali et al, 2017).…”

A novel generalized combinative procedure for Multi-Scalar standardized drought Indices-The long average weighted joint aggregative criterion

“…Some of them are available in Svoboda et al (2016). However, Standardized Drought Indices (SDI) procedures are the most commonly used and acceptable around the world (Erhardt and Czado, 2018). The important characteristics of SDI methods are that they are comparable.…”

“…All these standardized indices have the similar mathematical procedure and drought classification criterion. Erhardt and Czado (2018) acknowledged all these types of indices as a Standardized Drought Indices (SDI). The main advantages of standardized drought indices are to monitor and compare different regions with different time scales (Payab and T€ urker, 2019).…”