Environment and Public Health Microbiology Lab (EPHM Lab), Department of Civil Engineering, Monash University, Victoria, Australia.
Waterway Ecosystem Research Group, School of Ecosystem & Forest Sciences, The University of Melbourne, Victoria, Australia.
Water Res. 2022 Aug 15;222:118897. doi: 10.1016/j.watres.2022.118897. Epub 2022 Jul 24.
High levels of E. coli and associated faecal microbes in waterways as a result of agricultural and residential land use can pose environmental, human health, and economic risks. This study aims to understand the impacts of land use, climatic variables, and riparian buffers on in-stream E. coli concentrations. Flow, temperature, and E. coli were monitored during three sampling campaigns within eleven independent catchments. These catchments have varying land use and extents of riparian buffer coverage. Results showed that catchments with predominantly agricultural and residential land uses (average = 349.7 MPN/100 mL) had higher E. coli concentrations than predominantly forested catchments (average = 111.8 MPN/100 mL). However, there were no statistically significant differences in E. coli concentrations between the agricultural and residential land uses. Riparian buffers appear to reduce E. coli concentrations in streams, as indicated by significant negative correlations between in-stream E. coli concentrations with the riparian buffer areal coverage (Pearson's r = -0.95, Spearman's ρ = -0.90) and the ratio of buffer length to stream length (Pearson's r = -0.87, Spearman's ρ = -0.90). We find that riparian buffers potentially disrupt transport pathways that govern E. coli movement, which in-turn can affect the concentration-discharge relationship. This reinforces the importance of protecting and restoring riparian buffers along drainage lines in agricultural and rural-residential catchments to improve downstream microbial water quality.
由于农业和居住用地，水道中高水平的大肠杆菌和相关粪便微生物可能会带来环境、人类健康和经济风险。本研究旨在了解土地利用、气候变量和河岸带缓冲区对溪流中大肠杆菌浓度的影响。在 11 个独立流域的三次采样活动中监测了流量、温度和大肠杆菌。这些流域的土地利用和河岸带缓冲区覆盖范围各不相同。结果表明，以农业和居住用地为主的流域（平均为 349.7 MPN/100 mL）大肠杆菌浓度高于以森林为主的流域（平均为 111.8 MPN/100 mL）。然而，农业和居住用地之间的大肠杆菌浓度没有统计学上的显著差异。河岸带缓冲区似乎可以降低溪流中的大肠杆菌浓度，这表明溪流中大肠杆菌浓度与河岸带缓冲区面积覆盖率（皮尔逊 r = -0.95，斯皮尔曼 ρ = -0.90）和缓冲区长度与溪流长度之比（皮尔逊 r = -0.87，斯皮尔曼 ρ = -0.90）之间存在显著负相关。我们发现，河岸带缓冲区可能会破坏控制大肠杆菌迁移的运输途径，从而影响浓度-流量关系。这进一步强调了保护和恢复农业和农村居民流域排水线上的河岸带缓冲区，以改善下游微生物水质的重要性。
