title: Utilizing water characteristics and sediment nitrogen isotopic features to identify non-point nitrogen pollution sources at watershed scale in Liaoning Province, China.
abstract: Identifying nitrogen (N) pollution sources is the fundamental work of non-point source pollution load reduction from watersheds, but is hard due to complex N transport and transformation within spatially heterogenized huge areas. During September 2011, we measured water characteristics and sediment N stable isotope in four tributaries of the upper reach of the Hun River, an important water source of the Dahuofang Reservoir, a large drinking water source in Northeast China. Results showed that spatial changes in SO4 (2-) and Cl(-) contents in the tributaries were consisted with the changes in density of the population living along the tributaries. Sediment δ(15)N from all tributaries showed a downstream increasing trend in line with the land use change, which is characterized as more farmlands and more people around the outlet area of each tributary. Principal component analysis indicated the population density had a strong impact on N in these tributaries in the low-flow period. Tributaries and villages close to the Dahuofang Reservoir should be the major N load control objects in reduction of non-point source nitrogen load from the upper reach of the Hun River.
authors.affiliation: State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Science, 72 Wenhua Road, Shenyang, 110016, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ma
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.forename: Bin
authors.initials: B
authors.lastname: Huang
authors.forename: Yi
authors.initials: Y
authors.lastname: Shi
authors.forename: Guangyu
authors.initials: G
authors.lastname: Chi
authors.forename: Caiyan
authors.initials: C
authors.lastname: Lu
mesh_terms: D000641:Ammonia / Q000032:analysis; D002681:China; D019015:Geologic Sediments / Q000032:analysis*; D006801:Humans; D009584:Nitrogen / Q000032:analysis; D009587:Nitrogen Isotopes / Q000032:analysis; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060753:Water Quality
chemical_list: D009587:Nitrogen Isotopes; D014874:Water Pollutants, Chemical; D000641:Ammonia; D009584:Nitrogen