Assessment of ecological drought vulnerability of the Qinghai-Tibet Plateau from 2003 to 2022 based on multi-source data

Abstract

Ecological drought vulnerability (EDV) has become a focal point in global change research, underscoring the urgent necessity of establishing assessment criteria and estimating regional EDV using multisource data. We utilized a diverse array of data from 2003 to 2022, encompassing meteorological, hydrological, cryosphere, vegetation, soil, ecosystem, and land-use change information to develop a novel EDV index (EDVI) and construct spatial zoning for EDV land restoration for the unique ecological niches of the Qinghai-Tibet Plateau (QTP). The results demonstrated that (1) Locations with increased EDV accounted for a smaller area than those with decreased. The increased area of 933,497.75 km², 29.26 % of the total area, was mainly in the southern and northwestern regions. (2) Zones with continuously increasing (E5), sustained high increasing (E6), sustained high EDV (E3), and EDV increase (E2), which are extensively distributed across the northern and northeastern QTP, cover a total area of 820,579.75 km², accounting for 25.72 % of the total area. These regions should be considered when implementing restoration and management measures in areas with high EDV. (3) The land liquid water equivalent thickness (LWET) and canopy water amount (CWA), which are negatively correlated with EDV trends, show a decreasing trend. Conversely, carbon dioxide (CO₂), evapotranspiration (ET), and land surface temperature (LST), which are positively correlated with EDV trends, show an increasing trend. These changes exacerbate the EDV in the QTP. This study is crucial for formulating effective mitigation strategies against EDV in the QTP and serves as a reference for other regions.