Effects of Landscape Pattern on Water Quality at Different Spatial and Temporal Scales in Wuding River Basin and Yanhe River Basin.

To explore the relationship between land use and water quality in basins with different land use patterns at different spatial and temporal scales, the Wuding River Basin and Yanhe River Basin were taken as research objects. Based on land use data in 2020 and water quality monitoring data during two periods, the redundancy analysis method was adopted to quantitatively explore the impact of land use on water quality at multiple scales. The results showed that： ① The main land use types in the two basins were cultivated land and grassland, and the difference was mainly in the proportion of bare land and forest land. ② The water quality in spring was better than that in autumn, and the water quality in the middle and lower reaches was worse. ③ The interpretation rate of land use on the riparian scale was the highest in the two basins. ④ The effect of land use on water quality was more significant in the Wuding River Basin in autumn than in spring, whereas the Yanhe River Basin showed the opposite trend. ⑤ Different land uses had different impacts on water quality. Bare land, cultivated land, and Shannon diversity index （SHDI） in the Wuding River Basin had significant impacts on water quality, whereas grassland, cultivated land, artificial surface, patch density （PD）, and SHDI were significant in the Yanhe River Basin. Cultivated land and artificial surfaces in the Wuding River Basin had a negative impact on water quality. Grassland and bare land had a negative correlation with most chemical indicators. Artificial surfaces and grasslands in the Yanhe River Basin had a negative impact on water quality, whereas forest land had a significant purification effect. The research results provide important information for sustainable land use and multi-scale landscape planning, which can be used to improve water quality.