Runoff generation and phosphorus mobilization in agricultural landscapes

在以农业为主的流域中，非点源磷(P)的出口是一个全球性问题，也是加拿大许多地区的优先领域，在这些地区，在大型湖泊中观察到有害藻华(HAB)的频率越来越高。尽管实施了有益管理做法(BMP)来减少磷损失，但磷负荷并没有减少，实际上在一些地区还在增加。现有的磷输出和管理战略模型主要针对降雨事件驱动的地表径流，没有有效地处理冬季过程和融雪期。在全球许多中纬度地区，冬季是径流和磷的主要年通量，因此，有必要了解冬季和早春磷流失的驱动因素。

Phosphorus (P) export from non-point sources in agriculture-dominated catchments is a global issue, and a priority area for many regions in Canada, where Harmful Algal Blooms (HABs) have been observed in large lakes with increasing frequency. Despite the implementation of Beneficial Management Practices (BMPs) to reduce P loss, P loads are not decreasing and in fact are increasing in some regions. Existing models for P export and management strategies largely target rainfall event-driven surface runoff and do not effectively address winter processes and the snowmelt period. This period represents a significant gap in our scientific understanding of P mobilization in agricultural regions. In many midlatitude regions globally, the winter period is the dominant annual flux for both runoff and P. Thus, an understanding of the drivers of P loss in winter and early spring is needed.