Characteristics of Spatial and Temporal Variations of Global Terrestrial Droughts and Analysis of their Future Trends

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  • 1. College of Geography and Environmental ScienceNorthwest Normal UniversityLanzhou 730070GansuChina
    2. Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000GansuChina

Online published: 2025-02-24

Abstract

Drought represents a significant contributing factor to global climate-related disasters. It not only endangers the stability of global ecosystems and biodiversity but also has far-reaching implications for socio-eco‐ nomic development. As global climate change intensifiesso too does the frequency and intensity of droughts. Drought events in ecologically fragile regions not only threaten the availability of water resources but also in‐ crease the risk of food insecurityecological degradation and social conflict. Neverthelessdespite the growing body of research in this areathere remain significant gaps in our understanding of the spatial and temporal characteristics of drought occurrences over the past four decadesas well as its evolutionary trends under different cli‐ mate scenarios in the future. This study employs the Standardized Precipitation Evapotranspiration IndexSPEIand CMIP6 climate change scenarios to analyze the spatial and temporal characteristics of global droughts over the past four decades and to predict the evolution of global droughts under different climate scenariosSSP1- 2. 6SSP2-4. 5SSP5-8. 5over the next 80 years. The findings of the study indicate that:(1During the peri‐ od between 1980 and 2022there were notable variations in the spatial and temporal characteristics of global drought across different regions. Globallyapproximately 57% of the land area does not exhibit a significant drought trend. Howeverabout 33% of the land shows a persistent aridification trendparticularly in some al‐ ready arid regionswhere the intensity of drought has increased. Converselyonly 10% of the area is becoming wetterindicating that the regions of the globe that are becoming drier are significantly larger than those that are becoming wetter. This suggests that the aridification process is spreading globally;(2Over the past four de‐ cadesthe globe has experienced an arid trend with no significant seasonal differences. Howeverthe arid regions in winter are expandingaccounting for 33. 2% of the global land area;(3Different vegetation cover types exhibit varying responses to drought. Sparsely vegetated areas are more susceptible to droughtwhile densely vegetated areas tend to be wetter. Furthermorearid climate zones situated within diverse climatic contexts are confronted with more pronounced drought-related challenges. The largest proportion of severe drought is observed in extreme arid zoneswhich account for up to 67% of the global land areathis indicates a higher frequency of drought events in drylands;(4The probability of drought events is predicted to increase significantly in AfricaSouth Americasoutheastern Asiaand southern North Americaparticularly in tropical or warm climatic zonesextreme arid zonesand evergreen broadleaf climate zones. Furthermoredroughts are expected to become more frequent and severeespecially in tropical or very warm climate zonesarid zonesand broadleaf evergreen forest regions. The SSP5-8. 5 scenario is projected to have the highest probability and intensity of drought events over the next 80 yearsand will be challenged by more frequent and severe droughts. The findings of this study underscore the pervasive and severe nature of the global aridification trendparticularly in the context of climate changewhere the frequency and intensity of droughts are projected to increase significantly. This trend not only enhances our comprehension of the risk of droughtbut also furnishes an essential point of reference for policymakerswater managersand the general public. In order to mitigate the potential intensification of droughts in the futureit is imperative that all sectors of society implement more proactive and efficacious measures to promote adaptation and mitigate the challenges posed by droughts. The rational management of water resourcesimprovements in agricultural irrigation techniquesenhanced ecosystem resilience and the strengthening of monitoring and early warning systems for climate change and droughts will ensure global eco‐ logical security and facilitate sustainable socio-economic development.


Cite this article

XU Xinyao, WANG Xufeng, ZHANG Songlin, YANG Yanpeng, LI Zongxing . Characteristics of Spatial and Temporal Variations of Global Terrestrial Droughts and Analysis of their Future Trends[J]. Plateau Meteorology, 0 : 1 . DOI: 10. 7522/j. issn. 1000- 0534. 2024. 00109

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