Analysis of degradation trends and driving forces in priority wetland areas in the Shaanxi section of the Hanjiang River Basin from 1990 to 2020

To prevent further degradation of wetlands in the Shaanxi section of the Hanjiang River, this study investigated the landscape pattern changes and their driving forces in key wetland areas. Using seven periods of land-use remote sensing data (1990–2020) as the data source, we applied GIS spatial analysis, an area transfer matrix, landscape pattern indices, the InVEST model, and the PLUS model. The results revealed that from 1990 to 2020, wetland area decreased in the upper reaches (sub-watershed 21) but increased in the lower reaches (sub-watersheds 34 and 36). The primary landscape transformation was the conversion of paddy fields to dry farmland and construction land. The changes in wetland landscape patterns exhibited significant spatial disparities: fragmentation increased in the upper reaches, while the landscape remained relatively stable in the lower reaches. Changes in habitat quality aligned with the landscape pattern trends, showing a gradual decline in the upper reaches but no significant change downstream. Human production activities were identified as the primary driver of wetland degradation, with riparian population density and the density of secondary roads contributing the most significantly.