Study regionYellow River Basin (YRB) in China. Study focusThis study attempts to shed new light on regional land-atmosphere coupling and relevant impacts on basin-scale water resource management. Specifically, the objectives are to investigate the driving factors and physical mechanisms of SM changes via land-atmosphere coupling. New hydrological insights for the regionEcological conservation and the high-quality development in the YRB stand as a pivotal national strategy. The equilibrium of water availability (PME,precipitation minus evapotranspiration) poses a significant challenge to the sustainability of the basin's ecosystem. Unfortunately, a comprehensive examination of the regional response, spatiotemporal heterogeneity, and the mechanism governing soil moisture (SM) in response to PME remains limited. An enhanced multiple linear regression method is implemented to quantify monthly sensitivity coefficients, revealing a notable correlation: reduced SM in arid regions correlates with heightened PME. This decline in SM triggers a decrease in evapotranspiration, attenuates the cooling effect of evapotranspiration, and amplifies temperature disparities. Consequently, this process results in an intensified boundary layer and tropospheric ascending motion, thereby increasing water vapor transport. This feedback loop is most pronounced during drought conditions, particularly in summer arid areas (sensitivity coefficient =-0.27). The findings underscore the intricate interplay between land and atmosphere, elucidating the discernible impact of climate change on water resources at a sub-basin scale.