Objectives Through a scientific assessment of the impact of land use changes in the estuarine delta region on habitat quality, we systematically analyzed the underlying causes of the decline in regional habitat quality. This study aimed to serve as a decision-making reference for the high-quality development of the region.

Methods Using '3S' technology, this study analyzed the spatiotemporal changes in land use in the Liaohe Estuary area in 1980, 2000, and 2020. The InVEST model was employed to investigate the changes in habitat quality of the estuary.

Results Between 1980 and 2020, the terrestrial ecological space has expanded significantly, with the area increasing by 379.50 km², among which: the wetland area increased the most, totaling 373.17 km², and the unused land area decreased the most, with swampland decreasing by 240.06 km². The most drastic change was seen in construction land, with a dynamic degree of 2.52%. The InVEST model analysis indicated that the habitat degradation index showed that the habitat degradation in Liaohe Estuary was severe, with the area of moderate and high degradation continuing to increase. The areas with high habitat degradation were mainly around the Daling River Basin where woodland and grassland have been drastically reduced. The habitat quality index showed that from 1980 to 2020, the average habitat quality of the Liaohe Estuary gradually declined, and the habitat quality index was lower in the eastern region of the Liaohe Estuary, the Daling River Basin in the west and its two sides. The proportion of excellent and medium habitat quality decreased by 9.55% and 4.48%, while the proportion of good and poor habitat quality increased by 6.71% and 6.21%, respectively.

Conclusions Habitat quality was affected by land use change. The reduction in habitat quality and habitat degradation was mainly related to the reduction of grassland, woodland, and swampland.