Drought propagation as a nonlinear amplifier of ecohydrological damage

Meteorological drought can propagate to soil and ecological droughts, triggering cascading disruptions in ecosystem functioning. However, whether the ecohydrological damage—the sum of standardized vegetation greenness and soil moisture losses—is disproportionately amplified through drought propagation has not been systematically assessed. Using multiple global datasets, we found that ecohydrological damage reached 162% to 310% of the initial meteorological drought intensity. Once meteorological drought intensity exceeded the standardized threshold of 2.18, ecohydrological damage escalated nonlinearly. Externally, soil and ecological droughts were more sensitive to precipitation deficits and potential evapotranspiration surpluses, respectively. Internally, vegetation–soil feedbacks promoted the propagation from soil to ecological drought, while dampened the reverse process, resulting in the greatest ecohydrological damage along the meteorological–soil–ecological drought propagation pathway. Declining ecosystem resilience and increasing climate variability may exacerbate future drought propagation and its damage. These insights are critical for advancing early warning systems and mitigating cascading drought losses. Meteorological drought cascades into soil and ecological droughts, which disproportionately amplify ecohydrological damage to 162–310% of initial intensity, according to global remote sensing, observational, and reanalysis data.