农田氮磷流失与沟渠输移转化过程及影响因素
The Process and Factors of Nitrogen and Phosphorus Loss from Farmland and Transport in Ditch
-
摘要: 氮磷的不合理施用易导致农田氮磷盈余, 过剩的氮磷随着径流流失, 经过沟渠、河流输移进入受纳水体, 进而引发水体富营养化等环境问题。农田氮磷向沟渠的流失和在沟渠中的输移转化过程是农田氮磷向地表水体输移的关键过程。该研究通过文献调研, 从农田氮磷向沟渠的流失过程及其影响、氮磷在沟渠中的输移过程及影响因素和沟渠中氮磷去除评估方法3个方面综述了农田氮磷向地表水体输移过程的主要研究进展。当前有关农田氮磷在沟渠中的输移评估大多是从水文、温度、光照和河流形态等角度出发, 而对生物因素在沟渠氮磷输移中的影响尚未充分考虑, 且有关生物因素的研究主要集中在生态沟渠去除效果上, 关于生物因素对沟渠氮磷衰减的影响机制以及流域尺度沟渠生物状况时空特征的研究较少, 未来应采用综合评估方法定量评估生物状况在沟渠输移过程中的作用。该研究有助于深化对农田面源污染形成过程的认识, 为农田面源污染负荷核算和水环境保护提供参考。Abstract: The irrational application of nitrogen and phosphorus in farmland ecosystems leads to a surplus of nitrogen and phosphorus in farmland, which is lost through runoff and transported by ditches and rivers into receiving water bodies. Ultimately, this causes environmental problems such as the eutrophication of water bodies. The critical processes involved in the transport of nitrogen and phosphorus from agricultural land to surface water bodies include the loss of agricultural nitrogen and phosphorus to ditches and the transport and transformation processes in ditches. This paper summarises the main advances in agricultural nitrogen and phosphorus transport in ditches through literature research in terms of three aspects: the processes and factors of nitrogen and phosphorus loss from agricultural land to ditches, the transport process and factors of nitrogen and phosphorus in ditch and methods for assessing nitrogen and phosphorus removal from ditches. Previous watershed assessment studies were mostly from the perspective of hydrology, temperature, light and stream morphology, with insufficient consideration given to the impact of biological factors on nitrogen and phosphorus transport from ditches. Studies on biological factors have focused on the removal effects of ecological ditches, with less research on the mechanisms by which biological factors influence nitrogen and phosphorus attenuation in ditches and on the spatial and temporal characteristics of ditch biological conditions at the watershed scale. In the future, an integrated assessment approach to should be used to quantify the role of biological conditions in ditch transport. This research contributes to a deeper understanding of the formation of non-point source pollution in farmland, providing valuable insights for calculating pollution loads and protecting water environments related to agricultural non-point source pollution.