Non-point source pollution estimation in the Pingqiao River Basin,China, using a spatial hydrograph-separation approach |
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| Authors: | Han Xue Kaoru Takara Bin He Guangwei Huang Weili Duan |
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| Institution: | 1. Civil and Earth Resources Engineering, Kyoto University, Kyoto, Japan;2. Institute for Studies of the Global Environment, Sophia University, Tokyo, Japan;3. Disaster Prevention Research Institute, Kyoto University, Kyoto, Japan;4. Nanjing Institute of Geography &5. Limnology, Chinese Academy of Sciences, Nanjing, China;6. Institute for Studies of the Global Environment, Sophia University, Tokyo, Japan;7. State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China |
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| Abstract: | For efficient and targeted management, this study demonstrates a recently developed non-point source (NPS) pollution model for a year-long estimation in the Pingqiao River Basin (22.3 km2) in China. This simple but physically reasonable model estimates NPS export in terms of land use by reflecting spatial hydrological features and source runoff measurements under different land-use types. The NPS export was separately analysed by a distributed hydrological model, a spatial hydrograph-separation technique, and an empirical water quality sub-model. Simulation results suggest that 57 890 kg of total nitrogen (TN) and 1148 kg of total phosphorus (TP) were delivered. The results, validated with observed stream concentrations, show relative errors of 23.3% for TN and 47.4% for TP. Countermeasures for urban areas (5.3% of total area) were prioritized because of the high contribution rate to TN (14.1%) and TP (26.2%) which is caused by the high degree of runoff (8.5%) and pollution source. |
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| Keywords: | non-point source (NPS) pollution estimation hydrograph separation time–space accounting scheme land use urban NPS pollution |
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