Presentation by Andrew Warren (Deltares, Netherlands) at the Climate Adaptation Symposium 2023, during the Delft Software Days - Edition 2023 (DSD-INT 2023). Wednesday, 29 November 2023, Delft.

1. Andrew Warren
Delft Software Days (DSD-INT 2023)
Climate Adaptation Symposium
Wednesday, 28 November 2023
Dynamic Adaptive Policy Pathways
Theory & Showcase

2. How best to plan for SLR?
2
Protect or nourish? Accommodate or advance? Nature based solution or retreat?
What to choose
where and when?
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3. How to plan for future WASH resilience?
Ecosystem protection
IWRM
Protection / relocation
vulnerable assets
Systems decentralization? Systems redundancy? Systems diversification?
3
What to choose
where and when?
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2023
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Climate
Adaptation
Symposium
2023

4. How much to adapt?
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Source: IPCC – SROCCC (2019)
Projected Changes in Extreme
Precipitation & Drought Frequency
Projected Sea Level Rise
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5. Under deep uncertainty decision makers
should aim for robust plans that can be
adapted over time
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6. 4. Develop and evaluate adaptation pathways
3. Identify actions and assess ATP/OTP conditions and timing
1. Describe system, objectives, uncertainties
5. Design adaptive plan: short-term actions, long-term options
and adaptation signals
Reassess
Actions
Reassess
2. Assess impacts of uncertainties/ identify opportunities:
adaptation/opportunity tipping points (ATP/OTP)
6. Implement the plan
7. Monitor: ATP approaching? Actions or reassessment?
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Adapted from Haasnoot et al. (2013). 10.1016/j.gloenvcha.2012.12.006
Dynamic Adaptive Policy Pathways (DAPP) approach

7. Vulnerability assessment:
• Under what conditions does the system perform
unacceptably?
• What are unacceptable outcome thresholds?
Not easy to answer in detail – especially without a model
“From the past we know we can cope with….”
Methods:
• Narrative assessment
• Expert judgement
• Model-based assessment
(sensitivity analysis, stress testing)
• Scenarios used to assess timing of ATP/OTP
Adaptation tipping points (ATP)
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DSD-INT
2023
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Climate
Adaptation
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2023

8. Adaptation Pathways Map
• Maps show different possible sequences of decisions to achieve objectives
• Scorecard helps to evaluate the pathways and decisions
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Haasnoot et al. (2013). 10.1016/j.gloenvcha.2012.12.006
Large Reservoir
Small Reservoir
Demand Management
Desalination

9. Minimizing ‘regret’ or maladaptation
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Transfer costs
Stranded Assets Under-performance
Lock-ins
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10. Phased approach to DAPP
Level III: Full assessment of pathways
Requirements
for further analysis
and/or modelling
Narratives
Level II: Quantitative design of pathways
Level I: Initial qualitative pathways - narratives
11

11. • Initial quantitative study using available information/existing models
• Quantitative scenario development and vulnerability assessment
• ATP/OTP quantification → Pathways generator
-
5
10
15
20
25
30
0
0,5
1
1,5
2
2,5
M0
M1
M3(6)
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Level II: Quantitative design of pathways

12. • More extensive quantitative assessment using specialised tools for integrated
assessment, e.g. exploratory models / metamodels
• Model-assisted pathways development
• Intersection with other DMDU methods/tools:
→ Robust Decision Making (Lempert et al, 2013)
→ Decision Tree Framework (i.e. decision scaling) (Ray & Brown, 2015)
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Level III: Full (computational) assessment of pathways

13. Examples

14. Australian water utility biosolids strategy
• Semi-
quantitative
assessment
• Computational
modelling to
determine
sludge volumes
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Adaptation
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15. San Francisco, CA
Project combining
decision-scaling and
adaptation pathways to
plan for the next 50 years
at San Francisco Water
Under what conditions will the Hetch Hetchy Regional Water System
no longer meet levels of service and when?

16. San Francisco, CA
Change in precipitation scenarios
for system stress testing
Inflow into main reservoir Demand deficit indicator
Exploratory Modelling
Under what conditions will the Hetch Hetchy Regional Water System
no longer meet levels of service and when?
Model characteristics:
• Fast: simple representations of system functionality to execute large number of runs
• Integrated: represents interrelated systems and processes (climate, hydrology, reservoirs,
demand)
• Fit-for-purpose: represents dominant processes and natural variability, together with relevant
outcome indicators for decision making, without unnecessary detail

17. Vitens (NL): Improving DWI Resilience
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Supply risks Demand risks Network risks
• Climate change
• Source pollution
• Production site failure
• Increased competition for
resources (inc. environment)
• Demand growth/decline
• Demand spikes
• Independent abstractions
• New technologies
• Heterogenous network
arrangements
• Network connections
• Pipeline failures
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Climate
Adaptation
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2023

18. Long-term planning toolkit for resilient DWI
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Resources
Component
Demand
Component
Distribution
Network
Component
Climate conditions (T, E)
Economic growth
Water price
Technological development
Population change
Uncertainties
Service: reliability, robustness,
capacity usage
Capital Costs: Production plant
+ Network pipe cost
Strategic performance
metrics
Water quality/pollution
Supply capacity expansion
Network organization
Interventions
Demand management
Service disruption
DSD-INT
2023
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Climate
Adaptation
Symposium
2023

19. 21

20. 22
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21. 23

22. Adaptation pathways
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23. MYRIAD-EU
Developing forward-looking DRM pathways
• How to account for multiple hazards across multiple
sectors including all interdependencies and
interactions?
• Moving from DAPP to DAPP-MR
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Adaptation
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24. Waas-MR model
• Simulating 100 years, 10 day
timesteps
• Deep uncertainties: 3 climate
scenarios + 10 realizations for
climate variability
• On a “normal” Laptop: ~1.2 sec
per 100 year run

25. Key process – example flooding

26. Results – Stage 2
Pathways have some
(light) synergistic effect
on drought objectives

27. Questions?
www.deltares.nl | pathways.deltares.nl
andrew.warren@deltares.nl