The problem of agricultural 'diffuse' pollution: Getting to the point.

摘要: Despite introduction of legislation such as the EU Nitrates and Water Framework Directives (Directives 91/676/EEC 2000/60/EC respectively), agricultural practices are often still regarded a major factor in poor water quality across many member states. Elevated inputs nutrients, organic matter agro-chemicals to receiving waters from lands particular now widely recognised potentially causes deteriorating quality. Such may emanate diffuse sources fields, small point- or intermediate-sources, including farmyards farm trackways. However, while these latter intermediate be substantial, their overall contribution catchment-wide at high temporal spatial resolution is largely unknown. In this study, we surveyed chemistry throughout multiple natural artificial watercourses within single drainage network predominantly dairy farming area Southern Ireland. We found that most headwaters time study were impacted by via ditches emanating vicinity farmyards. These farmyard drains have elevated concentrations ammonium, phosphorus, potassium, suspended sediment biochemical oxygen demand above background levels catchment. Concomitant assessment macro-invertebrate communities sites indicated ecological was also impaired inputs. The individual aggregate contributions catchment, when mapped resolution, indicates they constitute catchment scale 'diffuse' our data suggest engineering maximise retention attenuation function prove cost-effective means mitigating effects point source