A METHOD FOR INVESTIGATING THE POTENTIAL IMPACTS OF CLIMATE‐CHANGE SCENARIOS ON ANNUAL MINIMUM GROUNDWATER LEVELS

Abstract

ABSTRACT Previous approaches to assessing the impact of climate‐change scenarios on groundwater levels and groundwater droughts have focused on modelling specific recharge processes or phenomena. However, statistical methods, based on correlations between historic groundwater level and rainfall time‐series, provide an alternative and robust approach to predicting minimum groundwater levels and droughts. For the purposes of this study, groundwater droughts are defined in terms of the return period of a given groundwater level. A multiple linear regression model (regression of monthly rainfall totals for a given period against values of minimum annual groundwater levels for the same period), when used with synthetic rainfall data based on climate‐change scenarios, enables changes in future annual groundwater‐level minima to be modelled. The method is illustrated at three sites on the Chalk, Permo‐Triassic sandstone and Jurassic limestone aquifers.