Connecting large-scale atmospheric circulation, river flow and groundwater levels in a chalk catchment in southern England

JOURNAL OF HYDROLOGY

卷:523

Article

Lavers, David A.¹  Hannah, David M.²  Bradley, Chris² 

[1] Univ Calif San Diego, Scripps Inst Oceanog, Ctr Western Weather & Water Extremes, La Jolla, CA 92093 USA

[2] Univ Birmingham, Sch Geog Earth & Environm Sci, Birmingham B15 2TT, W Midlands, England

关键词: Groundwater;    Large-scale atmospheric circulation;    Composite analysis;    River Lambourn;    Southern England;   

DOI  :  10.1016/j.jhydrol.2015.01.060

来源: Elsevier

【 摘 要 】

Groundwater is an important water resource and globally it represents the largest distributed store of freshwater. In southern England, groundwater is a major source for public water supply, and many aquifers have recently experienced both extreme low and high groundwater levels. In this paper, we use observations of precipitation, river discharge and groundwater levels (1964-2010) and an atmospheric reanalysis to explore the large-scale climate patterns preceding the nine highest and lowest March river discharge and groundwater levels in the chalk catchment of the River Lambourn (Berkshire Downs, southern England). Peak monthly precipitation is shown to occur from October to January, while the highest river discharge and groundwater levels are found from February to April. For high discharge/groundwater levels, composite anomaly patterns of the mean sea level pressure show a stronger than average pressure gradient across the North Atlantic Ocean, with enhanced water vapour transport across southern England. For the lowest discharge/groundwater levels, a blocking high pressure system is found across the British Isles deflecting storms and precipitation to the north. Significantly, the intra-composite variability suggests that different sequences of atmospheric states may lead to high and low discharge/groundwater events. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free