School of Civil and Hydraulic Engineering, Dalian University of Technology, Dalian, Liaoning, China.
Water Sci Technol. 2010;62(10):2277-85. doi: 10.2166/wst.2010.464.
Pollution from nonpoint-source (NPS) nitrogen (N) and phosphorus (P) are the main causes of eutrophication in lotic, lentic and coastal systems. The climate of cold regions might play an important role in disturbing environmental behavior of NPS N and P, influencing simulation of watershed scale hydrologic and nonpoint-source pollution models. The losses of NPS N and P increase in regions of cold climate. In cold seasons, accumulations of N and P are accelerated in soil with increasing fine root and aboveground biomass mortality, decreasing plant nutrient uptake, as well as freezing soil. N and P transformation is disturbed by soil frost and snow. Moreover, factors such as physical disruption of soil aggregates, pollutant accumulation in snowpack, and snow melting can all increase the NPS N and P losses to the waterbody. Therefore, NPS N and P in first flush are more serious in cold climate. All these effects, especially frozen soil and snowpack, make great challenges to watershed scale hydrologic and nonpoint-source pollution models simulation in cold climate. Model improvements of snowmelt runoff, nutrient losses in frozen soil, as well as N and P behavior have been initiated and will be continued to evaluate in terms of their performances and suitability with different scale, hydrologic and geologic conditions in the future.
非点源（NPS）氮（N）和磷（P）污染是非流水体、静水和沿海水体富营养化的主要原因。寒冷地区的气候可能在干扰 NPS N 和 P 的环境行为方面发挥重要作用，影响流域尺度水文和非点源污染模型的模拟。在寒冷气候地区，NPS N 和 P 的损失增加。在寒冷季节，随着细根和地上生物量死亡率的增加、植物养分吸收的减少以及土壤冻结，土壤中 N 和 P 的积累加速。土壤冻结和积雪会干扰 N 和 P 的转化。此外，土壤团聚体的物理破坏、积雪中污染物的积累以及积雪融化等因素都会增加 NPS N 和 P 向水体的流失。因此，寒冷气候下的初期冲刷中 NPS N 和 P 更为严重。所有这些影响，尤其是冻土和积雪，给寒冷气候下的流域尺度水文和非点源污染模型模拟带来了巨大挑战。未来将继续启动和改进融雪径流模型、冻土中养分损失模型以及 N 和 P 行为模型，以评估它们在不同尺度、水文和地质条件下的性能和适用性。
