Impacts of land use and socioeconomic activity on river water quality
土地利用类型及其社会经济特征对河流水质的影响

Water quality is influenced by land uses in a watershed; however, it is not clear how the relationship further be modified by socioeconomic activities on the land uses. We assumed that land use types are significantly correlated with water quality in natural and semi-natural areas, while the intensified socioeconomic activities in urban areas change the relationship remarkably. To verify this hypothesis, we selected 11 small catchments in Beijing and Tianjin region to analyze the relationship between river water quality and land use types and its socioeconomic characteristics using small catchments comprehensive analysis and small catchments cluster analysis separately, and the impact of socioeconomic factors on the relationship through scenario analysis in the Wenyu River watershed. The small catchments cluster analysis showed that TN, TP, and NH4+-N were correlated with land use types in semi-natural areas, but they were correlated with socioeconomic characteristics in urban region, meaning that the diversity of socioeconomic factors changed or even weakened the correlation between land use and river water quality, which supported our hypothesis. We concluded that land use and socioeconomic factors should be considered synthetically when studying the relationship between water quality and its driving forces in a watershed at a regional scale.