Climate Change Allowances - Peak River Flow by Management Catchment

This dataset contains peak river flow allowances showing the anticipated changes to peak flow by management catchment. It contains information generated by UK Centre for Ecology and Hydrology using UK Climate projections.

The Environment Agency uses peak river flow allowances as benchmarks for the advice it gives as a statutory consultee for flood risk assessments and strategic flood risk assessments (https://www.gov.uk/guidance/flood-risk-assessments-climate-change-allowances). The Environment Agency also uses peak river flow allowances in guidance for risk management authorities when claiming Flood & Coastal Erosion Risk Management Grant-in-Aid in support of new projects, schemes and strategies (https://www.gov.uk/guidance/flood-and-coastal-risk-projects-schemes-and-strategies-climate-change-allowances).

Allowances are included for three future time-frames - 2020's, 2050's and 2080's. The 2020's epoch is 2015 to 2039, 2050's epoch is 2040 to 2069 and the 2080's epoch is 2070 to 2125.

The range of allowances included is based on percentiles. A percentile describes the proportion of possible scenarios that fall below an allowance level. The 50th percentile is the point at which half of the possible scenarios for peak flows fall below it, and half fall above it.

The:

- central allowance is based on the 50th percentile
- higher central allowance is based on the 70th percentile
- upper end allowance is based on the 95th percentile Attribution statement: © Environment Agency copyright and/or database right 2021. All rights reserved.

本数据集收录了峰值河流流量许可，展示了由管理流域所预期的峰值流量变化。数据由英国生态与水文研究中心基于英国气候预测生成。

环境署将峰值河流流量许可用作其作为法定咨询方的洪水风险评估和战略洪水风险评估的基准（https://www.gov.uk/guidance/flood-risk-assessments-climate-change-allowances）。环境署亦在风险管理部门申请洪水与海岸侵蚀风险管理补助金以支持新项目、方案及战略时，采用峰值河流流量许可作为指导（https://www.gov.uk/guidance/flood-and-coastal-risk-projects-schemes-and-strategies-climate-change-allowances）。

许可涵盖三个未来时间范围——2020年代、2050年代和2080年代。2020年代纪元为2015至2039年，2050年代纪元为2040至2069年，2080年代纪元为2070至2125年。

许可范围基于百分位数。百分位数描述了低于许可水平的可能情景的比例。第50百分位数是可能情景中一半峰值流量低于此点，另一半高于此点的位置。

具体包括以下许可类型：
- 中心许可基于第50百分位数
- 高中心许可基于第70百分位数
- 上限许可基于第95百分位数

归属声明：© 环境署版权和/或数据库权利2021。版权所有。