A systematic assessment of drought termination in the United Kingdom
A systematic assessment of drought termination in the United Kingdom
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DOI：
10.5194/hess-20-4265-2016
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发表时间：
2016-10
影响因子：
6.3
通讯作者：
S. Parry;R. Wilby;C. Prudhomme;P. Wood
中科院分区：
文献类型：
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作者：
S. Parry;R. Wilby;C. Prudhomme;P. Wood
抽象的。旱灾的结束可能与旱灾向洪灾的戏剧性转变有关。人们可能会更多地关注这些具有新闻价值和值得纪念的事件，但逐步终止干旱也给水资源管理者带来了挑战。本文将干旱终止定义为这一事件的一个独特阶段。利用52个英国流域的观测河流流量记录，展示了一种更系统和更客观的方法来检测干旱终止。该方法的参数由敏感性分析提供信息，该分析确保将重点放在多季节至多年干旱的终止上。由此产生的467个终止干旱的清单为英国的这一现象提供了前所未有的历史视角。国家和区域协调一致的旱灾终止事件是可以确定的，尽管它们的特点在重大事件之间和重大事件期间都有所不同。对1995-1998年和2009-2012年终止干旱事件的对比进行了更深入的研究。这些数据还被用来评估终止干旱的指标和集水区特性之间的潜在联系。干旱终止的持续时间与海拔高度(rS=−0.47)和集水区平均降雨量(rS=−0.42)呈中度负相关，这表明英国高地地区较潮湿的集水区往往经历较短的干旱终止。城市化程度较高的集水区往往会出现逐渐的干旱终止(与这些地区预期的华丽的水文响应相反)，尽管这可能也反映了典型的低地英格兰的集水区类型。干旱发育期的持续时间与干旱终止的持续时间(r_s=−=0.29)和终止速率(r_s=0.28)之间存在显著的相关性。这表明，干旱发展阶段延长后，往往会出现更短和更突然的干旱终止。库存有助于将个别事件置于长期背景下。2009-2012年的旱灾终止阶段在规模和空间足迹方面被认为是异常的，但泰晤士河流量记录发现，1930年之前发生了几次类似的事件。在适当的时候，年表可以为探索干旱终止事件的复杂驱动因素、长期变异性和影响提供基础。
Abstract. Drought termination can be associated with dramatic transitions from drought to flooding. Greater attention may be given to these newsworthy and memorable events, but drought terminations that proceed gradually also pose challenges for water resource managers. This paper defines drought termination as a distinctive phase of the event. Using observed river flow records for 52 UK catchments, a more systematic and objective approach for detecting drought terminations is demonstrated. The parameters of the approach are informed by a sensitivity analysis that ensures a focus on terminations of multi-season to multi-year droughts. The resulting inventory of 467 drought terminations provides an unprecedented historical perspective on this phenomenon in the UK. Nationally and regionally coherent drought termination events are identifiable, although their characteristics vary both between and within major episodes. Contrasting drought termination events in 1995–1998 and 2009–2012 are examined in greater depth. The data are also used to assess potential linkages between metrics of drought termination and catchment properties. The duration of drought termination is moderately negatively correlated with elevation (rs = −0.47) and catchment average rainfall (rs = −0.42), suggesting that wetter catchments in upland areas of the UK tend to experience shorter drought terminations. More urbanized catchments tend to have gradual drought terminations (contrary to expectations of flashy hydrological response in such areas), although this may also reflect the type of catchments typical of lowland England. Significant correlations are found between the duration of the drought development phase and both the duration (rs = −0.29) and rate (rs = 0.28) of drought termination. This suggests that prolonged drought development phases tend to be followed by shorter and more abrupt drought terminations. The inventory helps to place individual events within a long-term context. The drought termination phase in 2009–2012 was, at the time, regarded as exceptional in terms of magnitude and spatial footprint, but the Thames river flow record identifies several comparable events before 1930. The chronology could, in due course, provide a basis for exploring the complex drivers, long-term variability, and impacts of drought termination events.