Abstract
The impact and optimal control of non-point source (NPS) pollution on water environment have become the hot issues of current research. This paper simulates the characteristics of NPS pollution of Danjiang River Basin in 2013, 2014, 2016, and 2018 based on SWAT (Soil and Water Assessment Tool) model. The spatial and temporal distribution is analyzed, and the critical source areas (CSA) according to the intensity of pollution loss are identified. Then, we set up nine single best management practices (BMPs) and three combined BMPs in the CSA, and the reduction effects of NPS pollution load of BMPs at the HRU scale and sub-basin scale are evaluated. The main research conclusions are as follows: (1) Based on the measured water quality and quantity data of Danfeng section from 2011 to 2019, the mean concentration method and the runoff division method are used to estimate the NPS pollution load at the Danfeng section, the NPS pollution loads of the total phosphorus (TP), ammonia nitrogen (NH3-N) and COD account for a large proportion in the total loads, which are 60.95-75.91%, 39.43-56.40%, and 59.37-74.37%, respectively. (2) In terms of temporal distribution, the impact to NPS pollution load is ranked as runoff > sediment > rainfall. In terms of spatial distribution, sediment has a great impact on nitrogen and phosphorus NPS pollution load. (3) The unit area load index method and the natural crack point classification method are used to identify the CSA in the basin. The information-entropy-basedmulti-attribute decision-making method to evaluate the cost-benefit value of management measures shows that control measures preferentially use combined BMPs, and the comprehensive cost-benefit attribute value reaches above 0.8. When using a single BMP, the comprehensive attribute value of returning the grain plots to forestry is high, reaching 0.62, which is suitable for NPS pollution control in a small area; for large-scale NPS pollution control, terrace project, supplemented by residue cover and grassed waterways is the more effective way in the river basin.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
