Brett Michael T, Arhonditsis George B, Mueller Sara E, Hartley David M, Frodge Jonathan D, Funke David E
Department of Civil & Environmental EngineeringBox 352700, University of Washington, Seattle, Washington 98195, USA.
Environ Manage. 2005 Mar;35(3):330-42. doi: 10.1007/s00267-003-0311-z.
We conducted statistical analyses of a 10-year record of stream nutrient and sediment concentrations for 17 streams in the greater Seattle region to determine the impact of urban non-point-source pollutants on stream water quality. These catchments are dominated by either urban (22-87%) or forest (6-73%) land cover, with no major nutrient point sources. Stream water phosphorus concentrations were moderately strongly (r2=0.58) correlated with catchment land-cover type, whereas nitrogen concentrations were weakly (r2=0.19) and nonsignificantly (at alpha<0.05) correlated with land cover. The most urban streams had, on average, 95% higher total phosphorus (TP) and 122% higher soluble reactive phosphorus (SRP) and 71% higher turbidity than the most forested streams. Nitrate (NO3), ammonium (NH4), and total suspended solids (TSS) concentrations did not vary significantly with land cover. These results suggest that urbanization markedly increased stream phosphorus concentrations and modestly increased nitrogen concentrations. However, nutrient concentrations in Seattle region urban streams are significantly less than those previously reported for agricultural area streams.
我们对大西雅图地区17条溪流长达10年的养分和沉积物浓度记录进行了统计分析，以确定城市非点源污染物对溪流水质的影响。这些集水区主要由城市（22%-87%）或森林（6%-73%）土地覆盖，没有主要的养分点源。溪流水体中的磷浓度与集水区土地覆盖类型呈中度强相关（r2=0.58），而氮浓度与土地覆盖的相关性较弱（r2=0.19）且不显著（在α<0.05水平）。与森林覆盖率最高的溪流相比，城市化程度最高的溪流平均总磷（TP）含量高95%，可溶性活性磷（SRP）含量高122%，浊度高71%。硝酸盐（NO3）、铵（NH4）和总悬浮固体（TSS）浓度随土地覆盖变化不显著。这些结果表明，城市化显著增加了溪流中的磷浓度，并适度增加了氮浓度。然而，西雅图地区城市溪流中的养分浓度明显低于此前报道的农业区溪流中的养分浓度。
