Model Instance Title:
Marlborough and Berkshire Downs, South-west Chilterns (MabSWeC) Model
Model Instance Short Name:
MabSWeC
Description:
Projections of climate for the 2080s from an ensemble of global climate models (GCMs) run under a medium–high (A2) emissions scenario are used to simulate changes in groundwater resources of a Chalk aquifer in central-southern England. Few studies that have investigated the impacts of climate change on groundwater resources have addressed uncertainty. In this work the uncertainty associated with use of a suite of GCM outputs in catchment scale impact studies is quantified. A range of predictions is obtained by applying precipitation and temperature change factors, derived from thirteen GCMs, to a distributed recharge model and a groundwater flow model of the Chalk aquifer of the Marlborough and Berkshire Downs and south-west Chilterns in the UK. The ensemble average suggests there will be a 4.9% reduction in annual potential groundwater recharge across the study area, although this is not statistically significant at the 95% confidence level. The spread of results for simulated changes in annual potential groundwater recharge range from a 26% decrease to a 31% increase by the 2080s, with ten predicting a decrease and three an increase. Whilst annual recharge is not found to change significantly, the multi-model results suggest that the seasonal variation in the groundwater resource will be greater, with higher recharge rates during a reduced period of time in winter. The spread of predictions for changes in river baseflow, at the bottom of the largest river sub-catchment, is from −16 to +33% in March and from −68 to −56% in October. The effects of climate change are shown to depend significantly on the type of land-use. It is concluded that further research is required to quantify the effect of different vegetation types on Chalk covered by different thicknesses of soil and their response to a changing climate
Creation/Publication Date:
2011
Disciplines:
GROUNDWATER SCIENCE
Contact Details:
| Name | Organisation | Country | Email |
|
Chris Jackson
|
British Geological Survey
|
UK
|
crja@bgs.ac.uk
|
Time Interval Covered:
from:
01-Jan-1970
to:
31-Dec-2003
Spatial Extent:
Bounding Box (Lat/Long WGS84):
West:
-2.001
East:
-0.525
South:
51.303
North:
51.725
Scope of Vertical Extent:
Chalk and Palaeogene
Vertical Extent (metres above OD) Maximum:
250
Minimum:
20
Spatial Reference Systems of Datasets:
Horizontal Reference System:
WGS 84
Vertical Datum:
mean sea level height
Vertical Units:
metre
Grid Resolution:
| Spacing X | Spacing Y | Spacing Z | Cells X | Cells Y | Cells Z |
|
1000
|
1000
|
|
102
|
48
|
3
|
Time step interval:
month
Time step value:
4
Additional information (science questions addressed, assumptions etc.):
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Science Question
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How does using the results from different climate models affect the impact of climate change on groundwater heads and baseflow in the chalk of the Marlborough Downs, Berkshire and South-west Chilterns?
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Boundary Condition
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No flow all around; abstractions represent groundwater outflow to the London Basin in the south-east
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Initial Condition
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Steady state
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Data:
| Input Dataset Name | Version | URL Link | Parameter | Value | Units |
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Input Data
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Recharge
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Top of layers
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Bottom of Layers
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Hydraulic conductivity
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storage coefficient
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Storage coefficient
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River location and parameters
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Location of springs
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| Output Dataset Name | Version | URL Link | Parameter | Value | Units |
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Output Data
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Grounmdwater head
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Baseflow
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Springflow
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Documents and Published Papers available for this model instance: