Influences of Land Use on Sediment Pollution across Multiple Spatial Scales in Taihu Basin

Abstract

AbstractThe dynamic relationship between land use and sediment pollutants in plain river network area were explored at multiple spatial scales. In our study, semi‐circle buffers (100, 200, 500, 1000, 1500, and 2000 m) were drawn to represent six spatial scales. Multivariate analysis, including principal component analysis, Pearson's correlation analysis, and stepwise regression analysis were used to detect the characteristic spatial scale of non‐point source pollution in Taihu Basin. The results suggested that paddy field, rural residential, build‐up, and vegetation are the most important indicators for sediment pollution variability, and sediment pollution was influenced by integrated effects of land uses. The same type of land use could produce different pollutant concentration. The impacts of anthropogenic land use on sediment pollution might have different characteristic spatial scale, e.g. 500 m buffer scale was identified as human disturbances spatial critical scale for total nitrogen, Hg, Pb, and Zn, 1000 m buffer scale for Cd, Cr, and Cu, 1500 m buffer scale for organic matter, and total phosphorus was significantly influenced by human activities in 1000–1500 m. We concluded that the 1000 m buffers on both sides of rivers which considered as the existing priority areas for environmental protection are not very effective in Taihu Basin and expanding the priority regions is therefore crucial to optimize their effectiveness. The identification of the characteristic spatial scale of anthropogenic disturbance could provide new ideas for water environmental protection management in Taihu Basin.