Chronology of drought termination for long records in the Thames catchment

Drought termination has been relatively neglected in the scientific literature, despite its importance for water resource managers and the often disruptive nature of this transitional period. There is a pressing need to systematically assess the nature of drought termination events in the historical record, and the use of long records potentially provides valuable information on the mechanisms of recovery. In this study, a novel approach for objectively defining and characterizing drought termination is applied to long records of river flow and groundwater level in the River Thames catchment. Chronologies of hydrological and groundwater drought termination are presented for 1883-2013 and 1933-2013, respectively. The chronologies show good agreement with known historical drought termination events, and examination of associated metrics allows the quantification of drought characteristics previously not possible. The parallel application to river flow and groundwater level data enables the assessment of propagation of drought termination through the hydrological cycle.