Emerging structural overshoot drought triggered by vegetation greening in the Yellow River Basin

Under global climate change, structural overshoot drought, triggered by vegetation exceeding ecosystem carrying capacity, has emerged as an ecological risk threatening agricultural sustainability. In the Yellow River Basin (YRB), a critical agricultural region experiencing rapid greening, the spatiotemporal patterns and irrigation management implications of structural overshoot drought remain unclear. To address this, we developed a Dynamic Linear Model (DLM) coupled with SHapley Additive exPlanations (SHAP) to assess structural overshoot drought across the YRB from 1982 to 2020. A significant warming-wetting trend was detected, with 84.5% of vegetated areas showing significant NDVI increases ( p < 0.05). Yet, 74.37% of these areas experienced soil moisture depletion, a greening-drying trade-off. Consequently, overshoot drought affected 15.91% of drought-affected areas, with 79.4% of events concentrated in the rapidly greening middle reaches, accounting for 26.34% of the regional drought-affected area. Among the driving factors, subseasonal (2–3 months) and seasonal (4–6 months) vegetation lag effects were the primary temporal drivers. SHAP analysis revealed NDVI and downward longwave radiation as the top two drivers, outweighing meteorological factors. Critically, irrigation played a dual role: pre-drought irrigation promoted vegetation overgrowth and soil drying, amplifying drought risk, while moderate drought-period irrigation replenished soil water and alleviated stress. Incorporating irrigation into the model raised the identified overshoot area from 15.91% to 17.29%. Overshoot drought frequency has increased over time, with future warming-wetting conditions projected to further exacerbate this risk. These findings provide a scientific basis for adaptive irrigation scheduling and ecological risk early warning in arid and semi-arid agricultural regions.