Impacts of land use and landscape pattern on water quality at multiple spatial scales in a subtropical large river

The coupling between land use/landscape pattern and water quality in river systems varies across different spatial temporal scales. It is important to understand the association scales for protection of resources. Here, we measured seasonal at 12 sub-basins upper reaches Han River (UHR) 2010 2018. We conducted factor analysis redundancy determine links use multiple identify main factors influencing quality. found that concentration nutrients, including total nitrogen, phosphorus, nitrate-N, ammonium-N were higher during wet season than dry season. Total nitrogen was driver nutrient pollution UHR, whereas phosphorus identified as another potential pollutant. also parameters more strongly related types Croplands urban lands increased concentrations water, forest grasslands decreased sub-basin scale. Land riparian zone better explained variations landscape metrics generally largest patch index Shannon's diversity predictors UHR.