Nutrient enrichment and eutrophication can increase when urbanisation and intensification of agriculture production occurs without accompanying mitigation measures to offset impacts from land use transitions. The identification of measures to protect or restore water quality is a challenging exercise, particularly in the context of increasing population and urbanisation. Hence, decision-makers need adequate tools to better understand and evaluate the effects of policy interventions on water management and quality control in urban regions. A model integration method was developed to assess future scenarios of urban development on water quality using land use model Monitoring Land Use/Cover Dynamics and nutrient emission model Source Load Apportionment Model. A case study application investigated how projected changes in urban land use in the most populated region of Ireland, the Greater Dublin Region, impact on water quality. Results for all scenarios indicate increasing losses to water for both phosphorus (18–25%) and nitrogen (9–12%). However, as these scenarios assume that wastewater treatment efficiencies remain static into the future, this study highlights that the magnitude and distribution of investment in urban wastewater collection and treatment will have the greatest impact on changes in future nutrient emissions to water in this urban region. The differences between the development scenarios for diffuse nutrient losses were small in comparison, even though the location of specific land uses varied broadly across scenarios. It was found that the decline of agricultural land cover and replacement with urban development in Dublin region by 2026 as represented by four modelled scenarios resulted in substantial increases in diffuse phosphorus emissions, but only slight changes in diffuse nitrogen emissions. It was shown that the scales of impact from sources of nutrients vary from scenario to scenario and that these should be considered alongside planned mitigation of point sources of nutrient emissions to water. Such information can support physical planners, catchment managers and policy makers to plan accordingly to get the best possible environmental outcomes. The case study application demonstrated that the loose one-way coupling of a land use model and a nutrient emission model can be an effective and inexpensive approach to improve understanding of the effects of urbanisation on water quality and assist in the strategic planning of catchment management and infrastructure investment.

当城市化和农业生产集约化发生时，如果不采取缓解措施来抵消土地使用过渡带来的影响，则营养富集和富营养化就会增加。确定保护或恢复水质的措施是一项具有挑战性的工作，特别是在人口增加和城市化的背景下。因此，决策者需要适当的工具来更好地理解和评估政策干预措施对城市地区水管理和质量控制的影响。开发了一种模型集成方法，以使用土地利用模型，监测土地利用/覆盖动态和养分排放模型，源负荷分配模型来评估城市发展在水质方面的未来情况。案例研究应用程序调查了爱尔兰人口稠密地区大都柏林地区城市土地使用的预计变化对水质的影响。所有情景的结果均表明，磷（18–25％）和氮（9–12％）的水损失正​​在增加。但是，由于这些情况假设废水处理效率在未来仍将保持不变，因此本研究强调指出，城市废水收集和处理投资的规模和分布将对该城市地区未来养分排放中的水的变化产生最大的影响。尽管特定土地用途的位置在各个情景中差异很大，但分散养分流失的发展情景之间的差异相对较小。研究发现，到2026年都柏林地区的农业用地覆盖率下降，并被城市发展替代，这是由四个模拟情景所代表的，这导致了磷扩散扩散的大量增加，但氮扩散的散发只有很小的变化。结果表明，不同情景下营养源的影响程度各不相同，应与计划中的减少营养物向水的主要排放源一起考虑。这样的信息可以支持自然规划者，集水区管理者和政策制定者做出相应的规划，以获得最佳的环境结果。