Increasingly dry/wet abrupt alternation events in a warmer world: Observed evidence from China during 1980–2019

Abstract

The evolution of the frequency of dry/wet spells is a hot topic in global climate change research. The synergistic effects of dry/wet spells make their consequences far more significant than a single disaster, having considerable impacts on hydrology, ecology, and economies, especially in the context of global warming. In this study, the standardized precipitation evapotranspiration index (SPEI)-based identification of dry/wet spells was used to explore the evolution of the frequency of dry/wet abrupt alternation (DWAA) events in the past four decades in China, makes up for the lack of research on the evolution of such compound disasters. China has been affected by dry/wet spells in many areas for a long time. Studies found that high-frequency DWAA areas are concentrated in densely populated areas, China's essential food bases and core areas for economic development. Dry-to-wet (D-W) events and wet-to-dry (W-D) events basically increased or decreased at the same pace in this period. We innovatively find DWAA events (D-W events and W-D events) are projected to occur increasingly in a wider region of China. The frequency of D-W events across China has increased from 2.35 in the 1980s to 3.56 in the last decade, a 50% increase. On the other hand, W-D events increased from 2.6 to 3.23, increasing 24%. The three regions with the most remarkable changes in the past four decades are Inner Mongolia, northwest China, and north China, where D-W events increased by 121, 61, and 58%, respectively, and W-D events increased by 71, 57, and 61%, respectively. Hereby, it is vital to implement effective prevention against DWAA events in the area which has been neglected in the past decades because of lower frequency. These results may help policymakers develop suitable disaster mitigation plans for reducing the potential risks of extreme compound natural events.

Identification and frequency analysis of drought–flood abrupt alternation events using a daily-scale standardized weighted average of the precipitation index

“…DFAA refers to the consecutive occurrence of drought and flood in a short time period (Wu et al, 2006b;Shan et al, 2018b;Chen et al, 2020a;Shi et al, 2021) and thus is a compound event generally caused by complex interrelationships between drought and heavy rainfall (Chen et al, 2020a). Although slight precipitation can occasionally alleviate drought conditions (Chen et al, 2020b), an abrupt alternation between drought and flood can cause substantial damage, which is even worse than a single disaster (Wu et al, 2006b;Handwerger et al, 2019;Chen et al, 2020b;He and Sheffield, 2020;Qiao et al, 2022). In addition, as DFAA usually coincides with the growth period of crops (Fan et al, 2019), it can bring enormous negative effects on agricultural production, ecosystems, and economic development (Clark et al, 2012;Huang et al, 2014;De Silva and Kawasaki, 2018;Fan et al, 2019).…”

“…Thus, it is important to effectively identify DFAA events in advance and explore the law of occurrence for DFAA disaster prevention and mitigation. There are two types of DFAA according to the sequences of drought and flood (Wu et al, 2006a;Shi et al, 2021;Qiao et al, 2022). One is from drought to flood (DTF), and the other is from flood to drought (FTD) (Qiao et al, 2022).…”

“…There are two types of DFAA according to the sequences of drought and flood (Wu et al, 2006a;Shi et al, 2021;Qiao et al, 2022). One is from drought to flood (DTF), and the other is from flood to drought (FTD) (Qiao et al, 2022). Specifically, DTF is a process in which flood occurs due to heavy rainstorms after prolonged drought; however, excessive rain is still insufficient to break the drought (Zhang et al, 2021).…”

“…Shan et al (2018a) developed a daily-scale index, a dry-wet abrupt alternation index with a fixed transition time of dry and wet stages, and analyzed the spatialtemporal characteristics of the transition between dry and wet spells in the summer. Chen et al (2020b) and Qiao et al (2022) explored the future changes of DFAA events in China using a monthly-scale index (i.e., the standardized precipitation evapotranspiration index). These previous studies have focused on distinguishing DFAA events over a long timescale (e.g., over a month) or a fixed transition time.…”

Sensitivity of WRF multiple parameterization schemes to extreme precipitation event over the Poyang Lake Basin of China

“…Precipitation is an important parameter of atmospheric motion as well as the water cycle. The natural disasters triggered by rainstorms have brought significant socioeconomic losses and human casualties (Jonkman 2005;Jia et al, 2022;Qiao et al, 2022). Due to climate warming, the frequency and intensity of extreme precipitation events have increased globally for most areas (Sun and Ao 2013;Stegall and Kunkel 2019;Yin et al, 2021;Yin et al, 2022).…”