The East Anglian region of the UK is a major agricultural producing region of the UK. The region also contains habitats of special environmental interest. It has one of the fastest growing population in the UK. Groundwater contributes over 50 % of total water supply in this area. The region is one of the driest areas of the UK and is at significant drought risk with competing demands on the water that is available.
Groundwater is typically represented as a fixed drought deployable output in regional water resource supply/demand system models in the UK. This approach means that it is not possible to operate groundwater and surface water conjunctively in these models. The environmental impact of groundwater abstraction (reduction in baseflow) is not evaluated directly.
Regional groundwater models in the UK provide a tool to assess groundwater availability and baseflow to streams in response to varying climate and demand. However, these models take hours to run and so aren’t suitable for integration into a water resources simulator. Here, we present the creation of ten lumped parameter models (LPM) in Python to represent regional groundwater availability across the East Anglian region. Inputs and outputs from seven regional groundwater models were used to calibrate the LPM. Empirical relationships were used to represent boundary conditions (baseflow to streams, evapotranspiration, flows across the LPM boundaries). Validation of the LPM gave confidence that these reduced-complexity lumped models could perform outside their calibration range.
The LPM were integrated into a larger water resource simulator which was used to evaluate many hundreds of future climate and demand scenarios. The innovative approach allowed the dynamic assessment of regional water availability in groundwater and surface water bodies and the calculation of environmental metrics.