Demonstrating the utility of a drought termination framework: prospects for groundwater level recovery in England and Wales in 2018 or beyond
Demonstrating the utility of a drought termination framework: prospects for groundwater level recovery in England and Wales in 2018 or beyond
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DOI：
10.1088/1748-9326/aac78c
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发表时间：
2018-06
影响因子：
6.7
通讯作者：
S. Parry;R. Wilby;C. Prudhomme;P. Wood;A. McKenzie
中科院分区：
文献类型：
--
作者：
S. Parry;R. Wilby;C. Prudhomme;P. Wood;A. McKenzie
在长期干旱期间，需要有关极端事件可能何时以及如何结束的信息。干旱终止框架的基础上的历史数据，包括目前的速度和历史集成方法在这里评估地下水水位恢复的前景。当前速率方法在历史记录中的所有初始化月份进行评估，并为一些缓慢响应的钻孔中相对严重的地下水位不足的恢复持续时间提供合理的估计。从2017年10月起，该框架的实用性通过近实时应用于英格兰和威尔士的30个地下水钻孔得到了证明。2017/18年冬季的恢复被认为是不可能的，因为一些含水层需要增加地下水位，而这在长期的历史记录中很少发生。截至2018年2月的数据证实了这些冬季前展望的成功。到2018年中到晚些时候或之后恢复的可能性更大;到2017年10月恢复速度缓慢，在夏半年的时间范围内恢复所需的有效降雨重现期增加，强调了冬季降雨的重要性，并表明历史集合可能低估了恢复的持续时间。在英格兰中南部和东部的一些反应缓慢的白垩钻孔中，人们对2018年底之后的恢复延迟有适度的信心。只要有足够的历史数据，干旱终止框架就有相当大的潜力在联合王国以外转让。这两种方法在明显不同的情况下提供的信息有限，其相关性和价值可能在空间和时间上有所不同，这表明它们是互补的，是将地下水水位恢复前景信息纳入现有季节性预测服务的最有力方式，支持水管理人员在长期干旱期间的决策。
During prolonged droughts, information is needed about when and how the extreme event is likely to terminate. A drought termination framework based on historical data comprising current rate and historical ensemble approaches is presented here for assessing the prospects of groundwater level recovery. The current rate approach is evaluated across all initialisation months in the historical record and provides reasonable estimates for the duration of recovery from relatively severe groundwater level deficiencies in some slowly responding boreholes. The utility of the framework is demonstrated through a near-real-time application to 30 groundwater boreholes in England and Wales from October 2017 onwards. Recovery during winter 2017/18 was considered unlikely, as some aquifers required increases in groundwater levels that have occurred seldom, if ever before, in long historical records. Data to February 2018 confirmed the success of these pre-winter outlooks. Recovery by mid- to late-2018 or beyond was more likely; slow rates of recovery by October 2017 and increasing return periods of effective rainfall required for recovery over timeframes in the summer half-year underlined the importance of winter rainfall and suggested that the historical ensemble may underestimate the duration of recovery. There was moderate confidence for a delay in recovery beyond the end of 2018 in some slowly responding Chalk boreholes in south-central and eastern England. There is considerable potential for the transferability of the drought termination framework beyond the UK wherever there are sufficient historical data. The two approaches provide limited information in distinctly different circumstances and their relevance and value may differ in space and time, suggesting their complimentary use as the most robust way to incorporate information on the prospects for groundwater level recovery into existing seasonal forecasting services, supporting decision-making by water managers during prolonged droughts.