On using flood-excess volume to assess natural flood management, exemplified for extreme 2007 and 2015 floods in Yorkshire
On using flood-excess volume to assess natural flood management, exemplified for extreme 2007 and 2015 floods in Yorkshire
复制标题
使用洪水过剩量评估自然洪水管理，以约克郡 2007 年和 2015 年极端洪水为例
DOI：
--
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
T. Kent
中科院分区：
文献类型：
--
作者：
O. Bokhove;M. Kelmanson;T. Kent
本文提供了一个协议进行定量评估的相对优点，现有的和拟议的方法的自然洪水管理（NFM）。评估是基于很少使用的概念，洪水过量体积（FEV），它近似量化的水的体积，希望通过防洪减灾计划，消除，并举例说明使用公开的河规数据最近众所周知的极端洪水事件在约克郡，英国。下面的问题激发了这项研究：一个特定的（一套）防洪措施减少了FEV的多少比例，以及以什么样的成本？提出的方法承认并列成本评估，不同的和流行的NFM措施，既不提供也不考虑在现有的防洪减灾政策。考虑到颁布一个社会有用的协议，量化和解释的替代成本方案是方便使用作者的新颖的可视化洪水缓解盆地部分填充，现实的建设，两米深的方湖边长约1至2公里。在第一个案例研究中，一个假设的洪水缓解计划，在Mytholmroyd的河卡尔德，包括流量衰减功能，植树和泥炭恢复，水库蓄水，严格评估合理的成本估算。分析的明确量化和直观表示表明，NFM措施减少的FEV分数虽然并非微不足道，但与水库的仔细抽水相比相形见绌。第二个案例研究，在谢菲尔德的顿河，通过一系列的情况下，试图采样现实的季节性降雨分布在整个流域的分析，并在这样做阐明了在不同的条件下，许多缓解计划的潜力和不确定性。我们证实了越来越多的共识，虽然NFM措施可以减少低水位洪水在当地，他们是有效的空间尺度是有限的，可能不会升级到集水区的水平。因此，我们的FEV分析和协议不仅提供了一个简洁的量化不同的和串联的防洪减灾措施的有效性，但也进一步突出了NFM的可扩展性的问题。
This paper offers a protocol for conducting a quantified assessment of the relative merits of both existing and proposed methods of Natural Flood Management (NFM). Assessment is based on the rarely used concept of flood-excess volume (FEV), which approximately quantifies the volume of water one wishes to eliminate via flood-mitigation schemes, and is exemplified using publicly available river-gauge data for recent wellknown extreme-flood events in Yorkshire, UK. The following question motivates the study: what fraction of the FEV is reduced, and at what cost, by a particular (suite of) flood-mitigation measure(s)? The approach presented admits juxtaposed cost assessments, of disparate and popular NFM measures, that are neither available nor considered in existing flood-mitigation policy. With promulgation of a societally useful protocol in mind, quantification and interpretation of alternative cost scenarios are facilitated using the authors’ novel visualisation of flood-alleviation basins as partially filled, realistically constructible, two-metre-deep square lakes of side-length approximately one-to-two kilometres. In the first case study, a hypothetical flood-alleviation scheme for the River Calder at Mytholmroyd, comprising flow-attenuation features, tree planting and peat restoration, and reservoir storage, is critically assessed alongside reasonable cost estimates. The clear quantification and visual representation of the analysis indicate that the fractions of FEV reduced by the NFM measures, while not insignificant, are dwarfed by the careful draw-down of reservoirs. The second case study, of the River Don at Sheffield, extends the analysis via a range of scenarios that attempt to sample realistic seasonal rainfall distributions across a catchment, and in doing so elucidates both the potential and uncertainty of numerous mitigation schemes under different conditions. We corroborate the growing consensus that, while NFM measures can reduce low-level flooding locally, the spatial scale at which they are effective is limited and may not upscale to the catchment level. Our FEV analysis and protocol thus not only offers a concise quantification of the effectiveness of disparate and in-tandem flood mitigation measures but also further highlights the issue of NFM scalability.