Eco-hydrological recovery following large vegetation disturbances from a mega earthquake on the eastern Tibetan plateau

Catastrophic earthquakes induce significant, enduring vegetation disturbances through extensive landslides and geomorphological alterations. The post-earthquake vegetation recovery hinges on the disturbance severity, climatic variability, and strategic human intervention, yet understanding of these critical processes and their influences on eco-hydrological functions at the landscape level remains limited. This study aims to quantify the earthquake's impacts on vegetation structure and eco-hydrological functions and to elucidate the recovery mechanisms driven by climate variability and human efforts. We focused on the 2008 Wenchuan Earthquake on China's eastern Tibetan plateau as a case study to investigate its influences on vegetation cover and eco-hydrological functions in gross primary productivity (GPP), evapotranspiration (ET) and water yield (WY) using remote sensing, spatial-resolved causal impact analysis, and ecohydrological modeling. We found that the earthquake caused widespread vegetation disturbances from 2008 to 2010, altering land cover over 12% of the study area, and reducing GPP and ET by 7.0% and 14.7%, respectively. During this period, the affected regions witnessed a larger variation in WY, primarily due to a decrease in ET. From 2010 to 2018, GPP and ET showed rapid recovery, driven by both climatic factors (accounting for 23%-56% of the recovery), and human intervention (contributing 30%-42% to the recovery). Though WY did not show a statistically significant trend, human intervention-induced ET change was responsible for 38.9% to the changes in WY during the recovery period. Nevertheless, by 2018, 45% of the affected area still had not returned to pre-earthquake levels, with recovered areas remaining below the projected non-earthquake levels, indicating the vulnerability of mountainous ecosystems in recovery. Our findings highlight the significant, long-lasting eco-hydrological impacts of a catastrophic earthquake and underscore the effectiveness of integrating natural regeneration with targeted human restoration efforts. These insights improve our understanding of ecological vulnerability and resilience following natural hazards, providing valuable guidance for future post-natural disaster restoration initiatives.

Duke Scholars

Author Wenhong Li Earth and Climate Sciences