Waterway Ecosystem Research Group, School of Ecosystem and Forest Science, The University of Melbourne, Burnley, Victoria, 3121, Australia.
Waterway Ecosystem Research Group, School of Ecosystem and Forest Science, The University of Melbourne, Burnley, Victoria, 3121, Australia.
J Environ Manage. 2019 Mar 1;233:1-11. doi: 10.1016/j.jenvman.2018.12.023. Epub 2018 Dec 12.
The potential for catchment-scale stormwater control measures (SCMs) to mitigate the impact of stormwater runoff issues and excess stormwater volume is increasingly recognised. There is, however, limited understanding about their potential in reducing in-channel disturbance and improving hydraulic conditions for stream ecosystem benefits. This study investigates the benefits that SCM application in a catchment have on in-stream hydraulics. To do this, a two-dimensional hydraulic model was employed to simulate the stream hydraulic response to scenarios of SCM application applied in an urban catchment to return towards pre-development hydrologic pulses. The hydraulic response analysis considered three hydraulic metrics associated with key components of stream ecosystem functions: benthic mobilization, hydraulic diversity and retentive habitat availability. The results showed that when applied intensively, the developed SCM scenarios could effectively restore the in-stream hydraulics to close to natural levels. Compared to an unmanaged urban case (no SCMs), SCM scenarios yielded channels with reduced bed mobility potential, close to natural hydraulic diversity and improvement of retentive habitat availability. This indicates that mitigating the effect of stormwater driven hydrological change could result in significant improvements in the physical environment to better support ecosystem functioning. We therefore suggest that intensive implementation of SCMs is an important action in an urbanizing catchment to maintain the flow regime and hydraulic conditions that sustain the 'natural' stream habitat functioning. We propose that stormwater management and protection of stream ecosystem processes should incorporate hydraulic metrics to measure the effectiveness of management strategies.
集水区尺度雨水控制措施（SCM）具有减轻雨水径流问题和过量雨水体积影响的潜力，这一点越来越得到认可。然而，对于它们在减少渠道干扰和改善溪流生态系统效益的水力条件方面的潜力，人们的理解有限。本研究调查了集水区中 SCM 应用对河道水力学的益处。为此，采用二维水力模型模拟了 SCM 应用于城市集水区以恢复到开发前水文脉冲的情景下河道水力响应。水力响应分析考虑了与溪流生态系统功能关键组成部分相关的三个水力指标：底栖迁移、水力多样性和保留栖息地可用性。结果表明，当密集应用时，开发的 SCM 方案可以有效地将河道水力学恢复到接近自然水平。与无管理的城市案例（无 SCM）相比，SCM 方案产生的渠道具有降低的床面迁移潜力，接近自然水力多样性，并改善了保留栖息地的可用性。这表明减轻雨水驱动的水文变化的影响可能会显著改善物理环境，以更好地支持生态系统功能。因此，我们建议在城市化集水区中密集实施 SCM 是维持维持“自然”河道栖息地功能的水流状态和水力条件的重要措施。我们建议，雨水管理和保护溪流生态系统过程应纳入水力指标来衡量管理策略的有效性。
