[Objective] The water and sediment changes in small and medium-sized rivers under the influence of human activities were analysed to provide scientific support for soil and water conservation and waterway water and sediment management in the watersheds. [Methods] The influence of landscape patterns on water and sediment changes in the basins was analysed based on water and sediment data and land use of the Nanliu and Qinjiang River basins from 1965 to 2021 using the landscape index, water-sediment mutation test, and other methods. [Results] ① Runoff and sediment transport in the Nanliu and Qinjiang River basins showed a gradual downward trend. The decreasing trend of sediment transport was more evident than that of runoff, and sudden change points in both runoff and sediment transport occurred in the 00s of the 21st century. ② The proportion of forestland in the Qinjiang River basin increased from 38% in 1990 to 41.6% in 2020, and the transfer area of cultivated land to forestland in the Nanliujiang River gradually increased. The policy of returning farmland to forests was effective, and the water-sediment change also showed a trend of gradual reduction. ③ The water-sediment changes in the two watersheds were negatively correlated with the degree of landscape fragmentation and positively correlated with the degree of patch aggregation. [Conclusion] In general, the land-use change within the Nanliu and Qinjiang River basins remained stable, and the water-sediment change was more obviously affected by land-use change; therefore, the relevant departments should strengthen the protection and management of eco-lands. Excessive interference of landscape patterns by human activities should be avoided, and landscape spatial configurations should be rationally planned to prevent soil erosion.