Temporary storage areas (TSAs) are a type of Natural Flood Management measure or nature-based solution that can provide additional storage during flood events by intercepting and attenuating surface runoff. Pressures on land use and an increase in climate change induced storms means there is a need to create additional storage within multifunctional rural landscapes. Implementation of small-scale TSAs is slowly gaining momentum, but practitioners still require further evidence on their functioning during different storm events. Here we present the TSA Drainage Rate Analysis tool (TSA-DRA tool), a novel data-based mechanistic method that only requires rainfall and TSA water level data to describe individual TSA drainage rates. We developed and then used the TSA-DRA tool to perform a multi-site assessment of different TSAs, allowing comparisons of TSA functioning across different types or time-variable factors. TSA design and outlet were found to be the dominant controls on drainage rates when the feature is full. Meanwhile, time-variable differences in functioning were more evident at lower water levels, when soil infiltration was the main TSA outflow. Results from a modelling experiment using observed time-variable TSA drainage rates suggested that these can impact the TSAs flood mitigation effectiveness. Specifically, for a particular event, soil conditions of a TSA in NE Scotland were more effective during spring than winter in attenuating surface runoff. Understanding spatial and temporal differences in TSA drainage rates will help optimise existing and future TSA designs, ensuring small-scale headwater TSAs are successfully integrated within rural catchments to mitigate an increasing exposure to hydrological extremes.

中文翻译：

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用于自然洪水管理措施运作的新的基于数据的分析工具揭示了多地点时变有效性

临时蓄水区 (TSA) 是一种自然洪水管理措施或基于自然的解决方案，可以通过拦截和减弱地表径流在洪水期间提供额外的蓄水空间。土地利用的压力和气候变化引起的风暴的增加意味着需要在多功能乡村景观中建立额外的存储空间。小规模 TSA 的实施正在慢慢获得动力，但从业者仍需要进一步的证据来证明其在不同风暴事件中的运作情况。在这里，我们介绍了 TSA 排水率分析工具（TSA-DRA 工具），这是一种基于数据的新颖机械方法，仅需要降雨量和 TSA 水位数据来描述各个 TSA 排水率。我们开发并使用 TSA-DRA 工具对不同 TSA 进行多站点评估，从而可以比较不同类型或时变因素的 TSA 功能。研究发现，当该功能已满时，TSA 设计和出口是对排水率的主要控制因素。同时，当土壤渗透是主要的 TSA 流出时，功能的时变差异在较低水位时更为明显。使用观察到的时变 TSA 排水率进行的建模实验结果表明，这些可能会影响 TSA 防洪效果。具体来说，对于特定事件，苏格兰东北部 TSA 的土壤条件在春季比冬季更能有效地减少地表径流。了解 TSA 排水率的空间和时间差异将有助于优化现有和未来的 TSA 设计，确保小规模的源头 TSA 成功整合到农村流域内，以减轻日益增加的极端水文风险。