Abstract: Estuarine zones, as transitional zones between land and sea, are significantly influenced by tidal forcing, which in turn affects water physicochemical properties and greenhouse gas emission processes. This study focused on the Aojiang River Basin in Wenzhou City, Zhejiang Province, systematically analyzing spatial variations in aquatic environmental factors (e.g., salinity, dissolved oxygen, water temperature, and nutrients) in the non-tidal segment, tidal segment, and estuarine segment. Based on generalized additive models (GAM), the study explored the nonlinear response patterns of greenhouse gases (CO₂, CH₄, N₂O) to multiple environmental factors. The results indicated that tidal processes significantly altered the salinity and dissolved oxygen (DO) status; salinity increased sharply to 6 214.38 mg/L in the estuarine segment, exhibiting strong spatial differentiation, whereas DO significantly decreased to 4.57 mg/L (p<0.05) under the influence of tidal mixing. In comparison, tidal processes had a relatively limited effect on the spatial distribution of nutrients, including nitrogen, phosphorus, and organic carbon. GAM results revealed that greenhouse gases exhibited distinct non-linear responses to environmental factors. The CO₂ model achieved an R² of 0.744, with DO identified as the primary driver (explaining 44.98%, p=0.008). The N₂O model showed the highest goodness-of-fit (R²=0.850), where salinity exerted a strong inhibitory effect (explaining 31.48%), and N₂O followed a distinct "double-peak" pattern with water temperature (peaks at 29 ℃ and 33 ℃). The CH₄ model reached an R² of 0.678, co-regulated by salinity inhibition (explaining 30.97%) and water temperature (explaining 28.24%). Overall, salinity, dissolved oxygen, and water temperature are key factors regulating greenhouse gas emissions: high-salinity conditions significantly suppress CH₄ and N₂O, while low DO promotes CO₂ release. These findings demonstrate that tidal processes, by altering the redox environment and hydrochemical conditions in the estuary, play a dominant role in shaping the greenhouse gas emission patterns.