Influence of land use and topography on total phosphorus export in Naoli River watershed, northeast China

Excess phosphorus in water has a profound effect on water quality, habitat condition, and trophic state of aquatic ecosystems. This study assessed the influence of land use change and topography on TP in water body of Naoli River watershed, northeast China. Correlation analysis showed that wetland in the watershed has no significant relationship with TP in the water, but the upland and residential area converted from wetland are important sources of TP in water, indicating that loss of wetland in the watershed has negative effect on water quality. Forest area and average slope of the watershed showed significant negative correlations with TP (p <= 0.05). Both natural and anthropogenic activities have strong influences on TP in Naoli River watershed. Establishment of the relationship between land use and TP can help us estimate the impact of the anthropogenic activity on TP in river water.