Elucidating Diverse Drought Characteristics from Two Meteorological Drought Indices (SPI and SPEI) in China

Abstract

This study elucidates drought characteristics in China during 1980–2015 using two commonly used meteorological drought indices: standardized precipitation index (SPI) and standardized precipitation–evapotranspiration index (SPEI). The results show that SPEI characterizes an overall increase in drought severity, area, and frequency during 1998–2015 compared with those during 1980–97, mainly due to the increasing potential evapotranspiration. By contrast, SPI does not reveal this phenomenon since precipitation does not exhibit a significant change overall. We further identify individual drought events using the three-dimensional (i.e., longitude, latitude, and time) clustering algorithm and apply the severity–area–duration (SAD) method to examine the drought spatiotemporal dynamics. Compared to SPI, SPEI identifies a lower drought frequency but with larger total drought areas overall. Additionally, SPEI identifies a greater number of severe drought events but a smaller number of slight drought events than the SPI. Approximately 30% of SPI-detected drought grids are not identified as drought by SPEI, and 40% of SPEI-detected drought grids are not recognized as drought by SPI. Both indices can roughly capture the major drought events, but SPEI-detected drought events are overall more severe than SPI. From the SAD analysis, SPI tends to identify drought as more severe over small areas within 1 million km2 and short durations less than 2 months, whereas SPEI tends to delineate drought as more severe across expansive areas larger than 3 million km2 and periods longer than 3 months. Given the fact that potential evapotranspiration increases in a warming climate, this study suggests SPEI may be more suitable than SPI in monitoring droughts under climate change.

Comparison of Projection in Meteorological and Hydrological Droughts in the Cheongmicheon Watershed for RCP4.5 and SSP2-4.5

“…Many other studies have also reported drought occurrences in the country [36][37][38]. Similar findings have been reported from North Korea [56][57][58], Japan [58], and China [59,60] that neighbor South Korea. There are also studies from other parts of the globe that have reported increased occurrences of droughts using SPI, SPEI, and SDI [61][62][63].…”

Representation of Plant Hydraulics in the Noah‐MP Land Surface Model: Model Development and Multiscale Evaluation

“…This process couples the water and carbon cycles and controls surface energy partitioning, thus playing a principal role in land surface and atmosphere/climate feedbacks (Bonan et al, 2008;Matheny et al, 2014a). A warming climate is expected to intensify the global hydrological cycle and induce more frequent and severe droughts (Dai, 2013;Li et al, 2020). Rising temperature will likewise cause an increase in atmospheric vapor pressure deficit (Grossiord et al, 2020).…”

Application of a hybrid ARIMA-LSTM model based on the SPEI for drought forecasting

“…The probability density function (PDF) that has been used for the SPEI is the log-logistic function, as suggested by Mckee et al (1993) and Vicente-Serrano et al (2010), respectively. Since both Yao et al (2018b) and Li et al (2020) used the SPEI to monitor the drought situation in China, the log-logistic PDFs are available for meteorological sites in China.…”

“…The SPEI is based on the SPI but adds a temperature component that allows the SPEI to account for the effect of temperature on the development of drought through basic water balance calculations (Soh et al 2018;Yao et al 2018b). Li et al (2020) elucidated drought characteristics of China during 1980-2015 using two commonly used meteorological drought indices: SPI and SPEI. Given the fact that potential evapotranspiration increases in a warming climate, Li et al (2020) show that SPEI may be more suitable than SPI in monitoring drought under climate change.…”

“…Li et al (2020) elucidated drought characteristics of China during 1980-2015 using two commonly used meteorological drought indices: SPI and SPEI. Given the fact that potential evapotranspiration increases in a warming climate, Li et al (2020) show that SPEI may be more suitable than SPI in monitoring drought under climate change.…”