Global warming has intensified water cycle processes, necessitating the study of atmospheric and terrestrial water dynamics across various arid-humid subregions under climate change. This work introduces the Capturability of Atmospheric Water (CAW) index, which measures the conversion of atmospheric to terrestrial water based on horizontal water vapor transport. We develop a conceptual framework to explore CAW evolution influenced by local and large-scale circulation factors. Our findings reveal significant spatial heterogeneity in CAW across different subregions. Specifically, CAW in semi-arid subregions (with precipitation of 200-600 mm yr(-1)) shows a marked increase during the cold season (November to March). Conversely, humid regions show a significant decrease in CAW, challenging the "dry gets drier, wet gets wetter" paradigm. Key hydrological variables in semi-arid regions, including precipitation, evaporation, and runoff, have increased, indicating an accelerated hydrological cycle over the past four decades. Our analysis reveals that local CAW changes are influenced by factors such as actual evapotranspiration, surface temperature, wind speed, and cloud cover. Notably, in about 80% (cold season) and 95% (warm season) of grids, there is a negative correlation between potential evapotranspiration and CAW, suggesting that increased atmospheric evapotranspiration capacity hinders the conversion of atmospheric water to precipitation. At a larger scale, CAW changes are influenced by large-scale circulation patterns, with equatorial Pacific Sea surface temperature anomalies playing a significant role in most of the semi-arid regions at low and middle latitudes. These findings have important implications for regional water resource management and climate adaptation strategies.