Hierarchical systems integration for coordinated urban-rural water quality management at a catchment scale.
Hierarchical systems integration for coordinated urban-rural water quality management at a catchment scale.
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DOI：
10.1016/j.scitotenv.2021.150642
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发表时间：
2021-09
期刊：
影响因子：
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通讯作者：
Leyang Liu;Barnaby Dobson;A. Mijić
中科院分区：
文献类型：
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作者：
Leyang Liu;Barnaby Dobson;A. Mijić
河流质量管理对于流域的可持续发展非常重要。在这项研究中，我们介绍了流域管理策略如何从基于了解污染关键驱动因素的措施的协调实施中受益。我们开发了一种建模方法，将环境影响、人类活动和管理措施整合为三个层次。我们提出了一个集水区水资源管理模型 (CatchWat)，该模型实现了所有三个层级，并应用于英国 Cherwell 集水区。 CatchWat 模拟根据观测到的河流流量和污染物数据（包括悬浮固体、总氮和总磷）进行评估。我们比较了流域表示的三种相互竞争的假设或框架（综合框架、仅限城市框架和仅限农村框架），以测试模型边界对河流水质建模的影响。制定情景模拟减少化肥施用和加强废水处理的单独、组合和协调实施。结果表明，模型必须同时代表城市和农村的污染排放量，才能准确估计河流质量。研究发现，农业活动可以提高丰水期河流的质量，因为径流是农村污染物的主要途径。同时，城市活动是干旱期污染的主要来源，因为在此期间污水占河流流量的比例较大。基于这一认识，我们确定了协调管理策略，在丰水期实施减肥措施以改善河流质量，并在干旱期加强废水处理以改善河流质量。协调策略的性能与组合策略相当，但总体效率更高。本研究强调了系统边界在综合水质建模和模拟季节性水质行为机制中的重要性。我们的主要建议是，需要纳入这些机制来制定河流水质管理的协调战略，最终可以实现更有效和可持续的流域管理。
Managing river quality is important for sustainable catchment development. In this study, we present how catchment management strategies benefit from a coordinated implementation of measures that are based on understanding key drivers of pollution. We develop a modelling approach that integrates environmental impacts, human activities, and management measures as three hierarchical levels. We present a catchment water management model (CatchWat) that achieves all three hierarchical levels and is applied to the Cherwell Catchment, UK. CatchWat simulations are evaluated against observed river flow and pollutant data including suspended solids, total nitrogen, and total phosphorus. We compare three competing hypotheses, or framings, of the catchment representation (integrated, urban-only, and rural-only framings) to test the impacts of model boundaries on river water quality modelling. Scenarios are formulated to simulate separate, combined and coordinated implementation of fertiliser application reduction and enhanced wastewater treatment. Results show that models must represent both urban and rural pollution emissions to accurately estimate river quality. Agricultural activities are found to drive river quality in wet periods because runoff is the main pathway for rural pollutants. Meanwhile, urban activities are the key source of pollution in dry periods because effluent constitutes a larger percentage of river flow during this time. Based on this understanding, we identify a coordinated management strategy that implements fertiliser reduction measures to improve river quality during wet periods and enhanced wastewater treatment to improve river quality during dry periods. The coordinated strategy performs comparably to the combined strategy but with higher overall efficiency. This study emphasises the importance of systems boundaries in integrated water quality modelling and simulating the mechanisms of seasonal water quality behaviour. Our key recommendation is that incorporating these mechanisms is required to develop coordinated strategies for river water quality management, that can ultimately lead to more efficient and sustainable catchment management.