Watershed Hydrology and Ecology Research Division, Environment and Climate Change Canada, Burlington, ON, Canada.
Watershed Hydrology and Ecology Research Division, Environment and Climate Change Canada, Saskatoon, SK, Canada.
Environ Monit Assess. 2023 Oct 9;195(11):1285. doi: 10.1007/s10661-023-11913-3.
This study conducted a spatio-temporal analysis of runoff, total suspended sediment, suspended particulate carbon, nitrogen, and phosphorus loadings within the 2.06 km Steppler subwatershed in southern Manitoba of Canada based on 11 years of field monitoring data collected at nine stations. Results showed that the nutrient losses were very small because of the implementation of multiple BMPs in the study area. However, a high spatio-temporal variation of runoff and water quality parameters was found for the nine fields within the subwatershed. The average runoff coefficient was 0.19 at the subwatershed outlet with sediment, suspended particulate carbon, total nitrogen, and total phosphorus losses of 73.8, 6.10, 4.54, and 0.76 kg/ha respectively. Spring snowmelt runoff was about 74.5% of the annual runoff at the subwatershed outlet, while for sediment, suspended particulate carbon, total nitrogen, and total phosphorus, the proportions were 61.1%, 63.6%, 74.9%, and 81.2% respectively during the monitoring period, which suggests that BMPs designed for reducing nutrient loadings from snowmelt runoff would be more effective than BMPs designed for reducing pollutant loading from rainfall storms in the study area. Research findings from this study will benefit the enhancement of current BMPs and the development of new BMPs in the region to minimize soil and nutrient losses from agricultural fields and improve water quality in receiving water bodies.
本研究基于在加拿大马尼托巴省南部的 2.06 公里的 Steppler 次流域内的 9 个站点收集的 11 年野外监测数据，对径流量、总悬浮泥沙、悬浮颗粒碳、氮和磷负荷进行了时空分析。结果表明，由于研究区域内采用了多种最佳管理措施（BMPs），养分流失很小。然而，次流域内的 9 个田块的径流量和水质参数存在很高的时空变化。次流域出口处的平均径流系数为 0.19，泥沙、悬浮颗粒碳、总氮和总磷的流失量分别为 73.8、6.10、4.54 和 0.76kg/ha。春季融雪径流约占次流域出口处年径流量的 74.5%，而在监测期间，泥沙、悬浮颗粒碳、总氮和总磷的比例分别为 61.1%、63.6%、74.9%和 81.2%，这表明设计用于减少融雪径流中养分负荷的 BMPs 将比设计用于减少降雨风暴中污染物负荷的 BMPs 在研究区域内更有效。本研究的研究结果将有利于增强当前的 BMPs 和开发该地区的新 BMPs，以最大限度地减少农业用地的土壤和养分流失，并改善受纳水体的水质。
