title: [Estimation of nonpoint source pollutant loads and optimization of the best management practices (BMPs) in the Zhangweinan River basin].
abstract: One of the key techniques in establishing and implementing TMDL (total maximum daily load) is to utilize hydrological model to quantify non-point source pollutant loads, establish BMPs scenarios, reduce non-point source pollutant loads. Non-point source pollutant loads under different years (wet, normal and dry year) were estimated by using SWAT model in the Zhangweinan River basin, spatial distribution characteristics of non-point source pollutant loads were analyzed on the basis of the simulation result. During wet years, total nitrogen (TN) and total phosphorus (TP) accounted for 0.07% and 27.24% of the total non-point source pollutant loads, respectively. Spatially, agricultural and residential land with steep slope are the regions that contribute more non-point source pollutant loads in the basin. Compared to non-point source pollutant loads with those during the baseline period, 47 BMPs scenarios were set to simulate the reduction efficiency of different BMPs scenarios for 5 kinds of pollutants (organic nitrogen, organic phosphorus, nitrate nitrogen, dissolved phosphorus and mineral phosphorus) in 8 prior controlled subbasins. Constructing vegetation type ditch was optimized as the best measure to reduce TN and TP by comparing cost-effective relationship among different BMPs scenarios, and the costs of unit pollutant reduction are 16.11-151.28 yuan x kg(-1) for TN, and 100-862.77 yuan x kg(-1) for TP, which is the most cost-effective measure among the 47 BMPs scenarios. The results could provide a scientific basis and technical support for environmental protection and sustainable utilization of water resources in the Zhangweinan River basin.
authors.affiliation: Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Water Sciences, Beijing Normal University, Beijing 100875, China. xuhuashan@mail.bnu.edu.cn
authors.forename: Hua-Shan
authors.initials: HS
authors.lastname: Xu
authors.forename: Zong-Xue
authors.initials: ZX
authors.lastname: Xu
authors.forename: Pin
authors.initials: P
authors.lastname: Liu
mesh_terms: D002681:China; D003362:Cost-Benefit Analysis; D018556:Crops, Agricultural / Q000254:growth & development; D004784:Environmental Monitoring; D005308:Fertilizers; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D011891:Rain; D045483:Rivers; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014876:Water Pollution / Q000191:economics / Q000517:prevention & control / Q000706:statistics & numerical data*
chemical_list: D005308:Fertilizers; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen