Influence of Atmospheric Phosphorus and Nitrogen Sedimentation on Water Quality in the Middle Route Project of the South-to-North Water Diversion in Henan Province

In order to understand the potential effects of atmospheric nitrogen and phosphorus deposition on the water quality of the Middle Route Project of the South-to-North Water Diversion Project, samples of dry and wet deposition of atmospheric nitrogen and phosphorus, meteorological factors, and water quality factors were analyzed out to investigate in the Middle Route Project of the South-to-North Water Diversion in Henan Province from October 2018 to October 2020. The variation characteristics of atmospheric nitrogen and phosphorus deposition with time in the Henan section of the main canal are revealed, and the influence of atmospheric dry and wet deposition on the water quality of the middle line is discussed. It was found that the total nitrogen (TN) sedimentation flux has obvious seasonal variation, which was consistent with the variation trend of rainfall, and increased with the increase of rainfall. Nitrogen and phosphorus deposition was significantly correlated with water factors. The effects of meteorological factors and nitrogen and phosphorus deposition on water quality variation reached 18%. The contribution rate and ecological impact of atmospheric nitrogen and phosphorus deposition on water pollution of main channels will be increasing, which needs to be paid enough attention to.