Multiple-Scale Analysis of Water Quality Variations and Their Correlation with Land use in Highly Urbanized Taihu Basin, China.

Understanding the relationship between land use and water quality at different scales is essential in the restoration and protection of water quality. On March 2014, we collected 97 samples in highly urbanized Taihu Basin and analyzed their water quality characteristics. Spatial differences in water quality were evident in sub-basins. The Hu Xi zone with the largest forest area had the best water quality among all the sub-basins. The correlation analysis indicated that the proportions of forest and construction land were significantly associated with multiple water quality variables from buffer to sub-basin scale. Farmland was significantly related to NO3-N at the sub-basin scale. The impact of landscape metrics at the sub-basin was insignificant. Forest and construction land in the 1-2 km buffer zone appeared to have a greater influence on the water quality than the buffers with smaller distance. These results are beneficial toward the understanding of water quality status in highly urbanized watersheds and provide a reference for water quality conservation and land use management in the future.