Abstract: Based on the landscape pattern index and hydrological connectivity index methods, the impact of changes in the spatial distribution pattern of wetland landscape types on wetland hydrological connectivity were explored in Yellow River estuary wetlands over the past 40 years (1986-2023). The results showed that herbaceous marshes, river wetlands, shrub wetlands, and croplands were fragmented, with dispersed landscape patterns. The patch connectivity of coastal tidal flat, reservoir pits, aquaculture ponds, salt ponds and construction lands had increased, and the landscape patterns were concentrated and compact. Hydrological connectivity in the wetland first declined and then increased, with overall poor connectivity. The patch area ratio (PLAND), average patch area (MPS) of herbaceous marshes were significantly positively correlated with overall connectivity index (IIC) and potential connectivity index (PC), while the splitting index (SPLIT) was significantly negatively correlated with PC. The landscape shape index (LSI) and SPLIT index of coastal tidal flats were significantly positively correlated with IIC and PC. The  LSI of river wetlands showed a significant negative correlation with PC. The   MPS of aquaculture ponds exhibited a significant negative correlation with IIC. Additionally, the  LSI correlated significantly negatively with both IIC and PC. There was no correlation between landscape pattern distribution of cropland and hydrological connectivity. Our results indicated that the evolution of landscape pattern affected wetland hydrological connectivity in the Yellow River estuary. This study provides a new theoretical perspective for hydrological connectivity research in the Yellow River estuary wetlands and offers references for the protection and optimization of hydrological connectivity.

Key words: landscape pattern, evolution process, hydrological connectivity, Yellow River estuary wetland