Assessing the impacts of climate change on ... - GroundwaterConclusions on climate change and...
Transcript of Assessing the impacts of climate change on ... - GroundwaterConclusions on climate change and...
Steven Wade, Chris Counsell and Ralph
Ledbetter, HR Wallingford Ltd
Assessing the impacts of climate
change on UK water resources –
groundwater
Page 1
Overview
Evidence of the impacts of climate change on water
resources
Preliminary results from the ARCC-Water project
on groundwater impacts
Using UKCP09 for climate change impacts
assessment
Challenges for future work
Page 2
UK CCRA 2012
Selection of Key National Threats
Climate change plus population
growth
Anticipated adaptation
•Reductions in demand will not be
sufficient on there own
Planned adaptation (excluded)
•RSA
•Abstraction reform
•Demand side and supply side
schemes
•Will environmental targets be
achievable without stronger
adaptation?
Evidence – Climate change and DO
Page 5
Mag
nit
ud
e Sensitivity
Individual
WRZ or small
companies
Policy background (WRP Guideline
Principles)
The Water White Paper identifies policy priorities:
> A long term perspective
> Water scarcity and environmental damage
> Water trading
> Reducing demand for water
The 25 year planning horizon….”does not constrain companies
from taking a longer term view where it is appropriate to do so…it
is important that the water resources management plans are
resilient to a range of potential climate scenarios and are
designed with climate risks built in.”
Page 6
Our approach (following the EA CC &
WSP project)
• Understand sensitivity to climate
Vulnerability Assessment
• Make full use of UKCP09 or Future Flows
Climate change assessment • Clear &
consistent approach to CC
Headroom
• Check plan is robust to range of CC scenarios
Decision making
© HR Wallingford 2011 Page 7
Flow Factors
DO assessment – general view of
levels of detail
Water resources system modelling (LoS)
Use all scenarios (or a subset?) in water resources zone models
Hydrological / hydrogeological modelling
Use flow factors or climate change factors or transient climate data in models (5 to 1000s)
Climate change projections
UKCP09 Rapid Assessment (5-20) Future Flows (11) UKCP09 (20 to 1000s)
Page 8
Trajectories of climate change impacts
Q95 - Thames at Eynsham
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
2000 2020 2040 2060 2080
Ch
an
ge (
%)
10th perc 50th perc 90th perc End of planning period
Q95 - Conwy
-100
-80
-60
-40
-20
0
20
2000 2020 2040 2060 2080
Ch
an
ge (
%)
10th perc 50th perc 90th perc End of planning period
Q95 Western Rother
-40
-30
-20
-10
0
10
20
2000 2020 2040 2060 2080
Ch
an
ge (
%)
10th perc 50th perc 90th perc End of planning period
Q95 based on UKCP09 scenarios
Groundwater issues (EA CC WSP
project)
Groundwater DO assessment presents some
difficulties
> Running lots of runs through distributed models and
translating to many sources is not practical
> Intermediate vulnerability method may have
limitations – similar to the former GR1 method
> However modelling recharge is straightforward
using FA0 56 or similar methods
Some pragmatism and innovation needed
Page 10
NERC “Future Flows” data sets for 24
groundwater observation boreholes
Page 11
http://www.bgs.ac.uk/research/groundwater/change/
FutureFlows/sites.html
http://www.ceh.ac.uk/sci_programmes/Water/Future
FlowsandGroundWaterLevels.html
Page 12
ARCC-Water Project Adaptive and Resilient Water Systems
EPSRC/ESRC-funded research into Water Resources Planning Ensemble of correlated, spatially coherent climatic projections for South-East
Regional Water System Model (RWSM) using IRAS-2010
Ensemble modelling of climate change impacts on water availability
Demand projections – informed by customer surveys, analysis and workshops
Multi-criteria robust decision-making to identify system vulnerabilities and test
alternative strategies (demand and supply side) – RDM, Real-Options, Info-GAP
Local studies in Anglian, Thames and Southern regions
Simple groundwater level modelling
approach for 45 sites in SE England
Page 13
Multiple Linear
Regression
Groundwater level
versus monthly recharge
Recharge estimate
based on FAO method
Return Period Analysis
Estimation of future levels using
UKCP09 SCPs and resampling
methods
Simple groundwater level modelling
2030s Medium Emissions climate
Page 14
-20 -15 -10 -5 0 5 10 15 20
aws_ps_belstead
stansted
tank_hall
duckpit_farm
lilley_bottom
dane_court_farm
chalfont_centre
lower_barn_cottage
charing
elsenham_nurseries
lowtherville_school
cross_in_hand_knaves
therfield_rectory
lower_wield_farm
poulton_valley
rockley
woodside
downend
rakeshole_east
verge_b1061_newmarke
12_acre_wood
little_bucket_farm
wolverton_old
elms_vale
north_court_wood
chalk_dale_owslebury
whitelot_bottom
nr_warren_tower_newm
clanville_lodge
folly_cottage
rodmersham
trackside_twelve_acr
stonor_park
ryarsh_bh2
verge_springhead_fm
well_house_inn
west_dean_bh_3
rose_and_crown
northend_stud_exning
elphicks_farm
symonds_farm_saxham
aws_ps_whitton_old
houndean_bottom
% change in annual minimum groundwater level
Reduction in
annual minimum
level for 80% sites
Comparison with Future Flows modelled
groundwater levels for 6 sites
Page 15
Figure Error! No text of specified style in document..1 Lower Barn Cottage: FFGWL comparison
of observed record (black) and R-Groundwater simulated (cyan). Taken from FFGWL fact sheet
for Lower Barn Cottage.
Figure Error! No text of specified style in document..2 Rockley: FFGWL comparison of observed
record (black) and R-Groundwater simulated (cyan). Taken from FFGWL fact sheet for
Rockley.
Figure Error! No text of specified style in document..3 Stonor Park: FFGWL comparison of
observed record (black) and R-Groundwater simulated (cyan). Taken from FFGWL fact sheet
for Stonor Park.
Prudhomme, C, Dadson, S, Morris, D, Williamson, J, Goodsell, G,
Crooks, S, Boelee, L, Davies, H, Buys, G, Lafon, T. 2012. 'Future
Flows Climate', http://dx.doi.org/10.5285/bad1514f-119e-44a4-8e1e-
442735bb9797
Haxton, T, Crooks, S, Jackson, C R, Barkwith, A K A P, Kelvin, J,
Williamson, J, Mackay, J D, Davies, H, Young, A, Prudhomme, C.
2012. 'Future Flows Hydrology', http://dx.doi.org/10.5285/f3723162-
4fed-4d9d-92c6-dd17412fa37b
Comparison with other
published models shows a
similar level of performance
and that all models struggle
with reproducing levels (and
by inference DOs) in the
same drought years
Water resources planning
Practical use of UKCP09 – PET
Page 16
Water Resources Planning: Practical
use of UKCP09 - Sampling methods
Page 17
Practical use of UKCP09 - Sampling
methods based on recharge
Page 18
Median – no change
However there is a risk of
a significant reduction
Conclusions on climate change and
groundwater Impacts on water resources and groundwater
> Climate change may have a significant impact on the supply-
demand balance in England by the 2030s
> Groundwater impacts are evident in 80% of sites modelled in SE
England; changes in average annual minima are small< 5%
> Groundwater could be an important part of adaptation to climate
change; demand side measures are not enough on their own
For better assessments we need
> Improved data on source performance under drought conditions,
possibly source works models
> Better access to existing EA groundwater models
> A step change in modelling speed Page 19
Conclusions
Page 20
Vulnerability and DO assessment
N=5-20
runs N=11-10K
runs
Climate change
vulnerability
assessment
Low vulnerability
Medium-High vulnerability
Large investments driven by
climate change
Use 20 LHS of
UKCP09 from
UKWIR study
2009
Use FF 11
RCM climate
monthly
factors
(based on
bias-
corrected
data)
Rainfall-runoff
and/or
groundwater
modelling
using
perturbed
data for time
slices for 20
scenarios
Water
resource
modelling for
30 year time
slices for
perturbed
data period
scenarios
Rainfall-runoff
and/or
groundwater
modelling
with
perturbed
data for time
slices for 11
scenarios
Water
resource
modelling for
30 year time
slices for
perturbed
data period for
11 scenarios
Use monthly
UKCP09 flow
factors (gw
not available)
from UKWIR
study 2009
Water
resource
modelling
using
perturbed data
for time slices
For 5
scenarios
Use FF
monthly flow
factors or
groundwater
factors
Water
resource
modelling
using
perturbed data
for time slices
for 11
scenarios
Use > =100
LHS of
UKCP09
Rainfall-runoff
and/or
groundwater
modelling
using
perturbed
data for time
slices for
>100
scenarios
Water
resource
modelling for
30 year time
slices for
perturbed
data period
for >100
scenarios
Use targeted
sample of
UKCP09
based on DI-
analysis
Rainfall-runoff
and/or
groundwater
modelling
using
perturbed
data for time
slices for 20
scenarios
Water
resource
modelling for
30 year time
slices for
perturbed
data period
for 20
scenarios
Approach
transient
climate data
Water
resource
modelling
using
transient data
for 11
scenarios
Rainfall-runoff
and/or
groundwater
modelling
with 11
transient
scenarios
Approach
Use FF
transient flow
data and
groundwater
Water
resource
modelling
using
transient data
for 11
scenarios
Climate change
vulnerability
assessment
Low vulnerability
Medium-High vulnerability
Large investments driven by
climate change
Approach 1.1:Use 20 LHS of
UKCP09 from
UKWIR study
2009
Approach 1.3:
Use FF 11
RCM climate
monthly
factors
(based on
bias-
corrected
data)
Rainfall-runoff
and/or
groundwater
modelling
using
perturbed
data for time
slices for 20
scenarios
Water
resource
modelling for
30 year time
slices for
perturbed
data period for up to 20
scenarios
Rainfall-runoff
and/or
groundwater
modelling
with
perturbed
data for time
slices for 11
scenarios
Water
resource
modelling for
30 year time
slices for
perturbed
data period for
11 scenarios
Approach 1.2:
Use monthly
UKCP09 flow
factors (gw
not available)
from UKWIR
study 2009
Water
resource
modelling
using
perturbed data
for time slices
scenarios
Approach 1.4:
Use FF
monthly flow
factors or
groundwater
factors
Water
resource
modelling
using
perturbed data
for time slices
for 11
scenarios
Approach 2.1:
LHS of
UKCP09
Rainfall-runoff
and/or
groundwater
modelling
using
perturbed
data for time
slices for
>100
scenarios
Water
resource
modelling for
30 year time
slices for
perturbed
data period
for >100
scenarios
Approach 2.2: Use targeted
sample of
UKCP09
based on DI-
analysis
Rainfall-runoff
and/or
groundwater
modelling
using
perturbed
data for time
slices for 20
scenarios
Water
resource
modelling for
30 year time
slices for
perturbed
data period
for 20
scenarios
Approach 2.3:
Use FF
transient
climate data
Water
resource
modelling
using
transient data
for 11
scenarios
Rainfall-runoff
and/or
groundwater
modelling
with 11
transient
scenarios
Approach 2.4:
transient flow
data and
groundwater
Water
resource
modelling
using
transient data
for 11
scenarios