Evidence for change in the nature of groundwater drought in the UK since 1890

Groundwater is an important source of water for public supply, agricultural irrigation, and industry, as well as sustaining ecological flows to rivers, and it can be affected by drought. Groundwater droughts are characterised by lowered groundwater levels, reduced yields from boreholes, reduced baseflow and shortening of ephemeral streams. Episodes of historic drought are commonly used to benchmark and/or model future groundwater resources and for water resource management and drought planning purposes. Consequently, in order to prepare more effectively for future groundwater droughts, there is a need to better understand groundwater droughts from the recent past and to identify if and how features of groundwater droughts may have changed with time. Here we present the results of a preliminary analysis of the Standardised Groundwater level Index (SGI) for the UKs two longest groundwater level time series from Chilgrove House, Sussex, and Dalton Holme, Yorkshire (top right), to investigate if and how groundwater droughts have changed since the 1890s.