Decision Tools to Evaluate
Vulnerabilities and Adaptation
Strategies to Climate Change
The Water Resource Sector
Outline
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Vulnerability and adaptation with respect to
water resources
Viewing water resources from a ‘services’
perspective
Hydrologic implications of climate change
for water resources
Tools/models
WEAP model presentation
Role for Multi-Criteria Analysis (MCA)
Effective V&A Assessments

Defining V&A assessment
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Often V&A focuses on analysis over
assessment
Why? Because the focus is on biophysical
impacts, e.g., hydrologic response, crop
yields, forests, etc.
Assessment is an integrating process
requiring the interface of physical and social
science and public policy
Effective V&A Assessments
(continued)
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General questions
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What is the assessment trying to influence?
How can the science/policy interface be
most effective?
How can the participants be most effective in
the process?
General problems
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Participants bring differing objectives/
expertise
These differences often lead to dissention/
differing opinions – this is where MCA can
help in prioritization
Effective V&A Assessments
(continued)
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To be valuable, the assessment process requires
 Relevancy
 Credibility
 Legitimacy
 Consistent participation
An interdisciplinary process
 The assessment process often requires a tool
 The tool is usually a model or suite of models
 These models serve as the interface
 This interface is a bridge for dialogue between
scientists and policy makers
The Water Resource Sector
Water’s “Trade-Off” Landscape
Water for nature
Water for agriculture
Water quantity
Water quality
Seasonality of flow
Regulation
Water for recreation
Domestic water
Water for industry
Water Resources from
a Services Perspective
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Not just an evaluation of rainfall-runoff or
streamflow
But an evaluation of the potential impacts of
global warming on the goods and services
provided by freshwater systems
Freshwater Ecosystem
Services
Extractable; Direct Use; Indirect Use
Harvest.
biota
Water
for ag.,
urban,
indust.
Recreation,
aesth.
beauty
Trans
-port
Upper
Rivers
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Lower
Rivers
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Delta
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Bay
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Power
gener.
Regen.
of soil
fertility
Nutr.
cycling
Flood/
drought
mitig.
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Water
purification
Erosion
control
Habitat
/
biodiversity
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Water Resources –
A Critical V&A Sector
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External
Pressure
Critical to both managed and natural systems
Human activity influences both systems
Managed
Systems
Product, good
or service
Process Control
Example: Agriculture
External
Pressure
Natural
Systems
State of System
services
Little Control
of processes
Example: Wetlands
Hydrologic ‘External Pressures’
related to Climate Change

Precipitation amount
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Precipitation frequency and intensity
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Global average increase
Marked regional differences
Less frequent, more intense (Trenberth et al.,
2003)
Evaporation and transpiration
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Increase total evaporation
Regional complexities due to
plant/atmosphere interactions
Specific Pressures: Retreating
Himalayan glaciers
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Forecasts of 25% losses globally by 2050; 50% by 2100
Specific Pressures: Retreating
Himalayan glaciers
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Meltwaters are depended upon during dry season to
sustain low flow periods
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Probable diminished volume and earlier timing of flows
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Has implications for hydropower production, agricultural
demands, and river and riparian quality and ecosystem
needs
Specific Pressures:
Sea level rise
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Sea level could rise by as much as 50 cm by 2100
(IPCC, 2001)
For islands, coasts:
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sea level rise, inundation of coast lines, and decreasing
infiltration of precipitation will lead to shrinking
groundwater lenses
Displacement of people will cause new localized stresses
on water resource allocation
water tables may rise to land surface, causing full
evapotranspiration and diminished water quality (Burns
2000)
Specific Pressures: Extreme
weather

Typhoons and cyclones could increase by 50-60%
(NASA, 2001), with intensities increasing by 10-20%
(IPCC 2001).

Possible doubling of frequency of 100 mm/day rainfall
events and 15-18% increase in rainfall intensity over
large areas of the Pacific (IPCC 2001).

This may lead to greater soil erosion and runoff, and less
water available for infiltration and evapotranspiration
Examples of Adaptation in
Water Resources
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Construction/modification of physical infrastructure
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Canal linings
Closed conduits instead of open channels
Integrating separate reservoirs into a single system
Reservoirs/hydro-plants/delivery systems
Raising dam wall height
Increasing canal size
Removing sediment from reservoirs for more storage
Inter-basin water transfers
Examples of Adaptation in
Water Resources
(continued)
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Adaptive management of existing water
supply systems
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Change operating rules
Use conjunctive surface/groundwater supply
Physically integrate reservoir operation
system
Coordinate supply/demand
Indigenous options
Examples of Adaptation in
Water Resources
(continued)
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Policy, conservation, efficiency, and technology
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Domestic
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Municipal and in-home re-use of water
Leak repair
Rainwater collection for non-potable uses
Low-flow appliances
Dual-supply systems (potable and nonpotable)
Agriculture
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Irrigation timing and efficiency
Drainage re-use, use of wastewater effluent
High value/low water use crops
Drip, micro-spray, low-energy, precision application
irrigation systems
Salt-tolerant crops that can use drain
water
Examples of Adaptation –
Water Supply (continued)
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Policy, conservation, efficiency, and technology
(continued)
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Industry
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Water re-use and recycling
Closed cycle and/or air cooling
More efficient hydropower turbines
Cooling ponds, wet towers and dry towers
Energy (hydropower)
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Reservoir re-operation
Cogeneration (beneficial use of waste heat)
Additional reservoirs and hydropower stations
Low head run of the river hydropower
Market/price-driven transfers to other activities
Using water price to shift water use between sectors
Tools in Water Resource
V&A Studies

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What tools are available to understand both
water resource vulnerabilities and evaluate
adaptation strategies?
How can stakeholders be engaged in these
processes?
Types of Water Resources Models
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Hydraulic: biophysical process models
describing streamflow, flooding
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Hydrology: rainfall/runoff processes
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Planning: water resource systems models
Which model?...
What questions are you trying to answer?
Hydraulic Model
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Critical questions
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How fast, deep is river flowing
How do changes to flow and channel morphology
impact sediment transport and services provided
(fish habitats, recreation, etc).
Hydrology Model
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Critical questions
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How does rainfall on a catchment translate into flow
in a river?
What pathways does water follow as it moves
through a catchment?
How does movement along these pathways impact
the magnitude, timing, duration, and frequency of
river flows, as well as water quality?
Planning Model
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Critical questions
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How should water be allocated to various uses in time of
shortage?
How can these operations be constrained to protect the
services provided by the river?
How should infrastructure in the system (e.g., dams,
diversion works) be operated to achieve maximum benefit
(economic, social, ecological)?
How will allocation, operations, and operating constraints
change if new management strategies are introduced into the
system?
Tools to Use for the Assessment:
Referenced Water Models
Operational and hydraulic

HEC
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HEC-HMS – event-based
rainfall-runoff (provides input
to HEC-RAS for doing 1-d
flood inundation “mapping”)
HEC-RAS – one-dimensional
steady and unsteady flow
HEC-ResSim – reservoir
operation modeling
WaterWare
RiverWare
MIKE11
Delft3d
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Hydraulic
Water Management Model
HEC-HMS watershed
scale, event based
hydrologic simulation,
of rainfall-runoff
processes
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Sub-daily rainfallrunoff processes of
small catchments
Free, download
from web
Tools to Use for the Assessment:
Referenced Water Models (continued)
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Planning/ hydrology
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WEAP21
Aquarius
SWAT
IRAS (Interactive
River and Aquifer
Simulation)
RIBASIM
MIKE 21 and
BASIN
Current Focus – Planning and
Hydrologic Implications of Climate Change

Selected planning/hydrology models: can be
deployed on PC, extensive documentation,
ease of use, free (or free to developing
nations)…
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Aquarius
SWAT (Soil Water Assessment Tool)
WEAP21 (Water Evaluation and Planning)
Physical Hydrology and
Water Management Models
AQUARIS advantage:
Has economic efficiency
criterion requiring the
reallocation of stream
flows until the net marginal
return in all water uses is
equal
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Cannot be climatically
driven – flows prescribed
by user
Economic focus
Physical Hydrology and
Water Management Models
(continued)
SWAT advantage:
Can predict effect of
management decisions on
water, sediment, nutrient
and pesticide yields on
ungauged river basins.
Considers complex water
quality constituents.
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Rainfall-runoff, river routing
on a daily timestep
Focuses on supply side of
water balance
Physical Hydrology and
Water Management Models
(continued)
WEAP21 advantage:
Seamlessly integrates
watershed hydrologic
processes with water
resources management

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Can be climatically driven
Based on holistic approach
of integrated water
resources management
(IWRM) – supply and
demand
IWRM Principles
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Freshwater is finite and has economic and
social value in its competing uses
Water is essential to sustain life and safe
water should be accessible to all
Water development and management should
be participatory, involving users, planners,
policy makers at all levels and recognize that
women in particular play a central role in
water provision for their families.
1992 International Conference on Water and Environment, Dublin, Ireland
IWRM Principles
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Promotes the coordinated development and
management of land, water and related
resources to maximize social and economic
welfare in equitable way without comprising
sustainability
Cross-sectoral integration in water policy
development
Global Water Partnership
IWRM Resources
Global Water Partnership at:
www.gwp.forum.org
Overview WEAP21
Hydrology and planning
Planning (water distribution)
examples and exercises
Adding hydrology to the model
User interface
Scale
Data requirements and
resources
Calibration and validation
Results
Scenarios
Licensing and registration
Data are organized in a tree
structure that you edit by rightclicking here.

Use the
View bar to
switch
between
your
analysis
and its
results.
You can create multiple scenarios and use
this box to switch between them.
Enter or edit
your data by
typing it
here.
Your data
are shown
here as
either a
graph or a
table.
A Simple System
with WEAP21
40
60
An Infrastructure Constraint
10 Unmet
30
70
A Regulatory Constraint
10 Unmet
30
70
IFR Met
Different Priorities
For example, the demands
of large farmers (70 units)
might be Priority 1 in one
scenario whereas the
demands of smallholders
(40 units) may be Priority 1
in another

40
60
0
10 unmet
Different Preferences
30
10
For example, a center
pivot operator may prefer
to take water from a
tributary because of lower
pumping costs

0
90
WEAP and Planning
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Provides a common framework for
transparently organizing water resource data
at any scale desired – local watershed,
regional or transboundary river basin
Scenarios can be easily developed to
explore possible water futures
Implications of various policies can be
evaluated
WEAP Capabilities
Can do
High level planning at
local and regional
scales
Demand management
Water allocation
Infrastructure
evaluation

Cannot do
Sub-daily operations
Optimization of supply
and demand (e.g. cost
minimizations or social
welfare maximization)
Uses of WEAP

Policy Research
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Alternative Allocations
Climate Change
Land Use Change
Infrastructure Planning
Capacity Building
Negotiation
Stakeholder Engagement
WEAP is Scenario-driven

The scenario editor readily accommodates
analysis of:

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Climate change scenarios and assumptions
Future demand assumptions
Future watershed development assumptions
Futures and Scenarios: Why?
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Scenarios: a systematic way of thinking about the
future
To gain a better understanding of the possible
implications of decisions (or non-decisions
across scales and time
To support decision-making
Driving Forces
Demographic
•More people
•Urbanization
•Older
Technological
•Computer and information technology
•Biotechnology
•Miniaturization
Economic
Environmental/Climatic
•Growing integration of global economy
•Increasing global stress
Social
•Increasing inequality
•Persistent poverty
Cultural
•Spread of values of consumerism and
individualism
•Nationalist and religious reaction
•Local degradation
•Some remediation in richer countries
Governance
•Global institutions
•Democratic government
•Role for civil society in decision-making
Who are the Actors?
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Government
Private sector
Civil society
Public
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Rich farmers
Poor farmers
Urban users
Environmentalists
Or?
Consider Sources of
Uncertainty
Ignorance
Understanding is limited
Surprise
The unexpected and the novel can alter directions
Volition
Human choice matters
Forecast and Backcast
?
Where is society going?
forecast
?
backcast
Where do we want to go?
How do we get there?
Study Definition
Spatial Boundary
Time Horizon
System Components
Network Configuration
Current Accounts
Demand
Reservoir Characteristics
River Simulation
Pollutant Generation
Resources and Supplies
Wastewater Treatment
Scenarios
Demographic and Economic Activity
Patterns of Water Use, Pollution Generation
Water System Infrastructure
Hydropower
Allocation, Pricing and Environmental Policy
Component Costs
Hydrology
Evaluation
Water Sufficiency
Pollutant Loadings
Ecosystem Requirements
Sensitivity Analysis
WEAP21 Program
Structure
The WEAP21 Graphical
User Interface
Use the
View bar to
switch
between
your data
and its
results.
Use the menu to do standard
functions such as creating
new areas and saving.
You can click and drag elements of the
water system from the legend onto the
schematic directly.
Languages:
Interface Only
English
French
Chinese
GIS layers
can be
added here.
Your can
zoom your
schematic
in or out
by sliding
the bar
here.
Spanish
Data are organized in a tree
structure that you edit by rightclicking here.
Use the
View bar to
switch
between
your
analysis
and its
results.
You can create multiple scenarios and use
this box to switch between them.
Enter or edit
your data by
typing it
here.
Your data
are shown
here as
either a
graph or a
table.
Data Requirements

WEAP allows the user to determine the level of
complexity desired


according to the questions that need to be
addressed
the availability of data
From the simple…
To the complex….
Data Requirements: Supply


User-prescribed supply (riverflow given as
fixed time series)
 Time series data of riverflows (headflows) cfs
 River network (connectivity)
Alternative supply via physical hydrology (let
the watershed generate riverflow)
 Watershed attributes

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Area, land cover . . .
Climate

Precipitation, temperature, windspeed, and
relative humidity
Letting Climate Drive Hydrology
The WEAP 2-Bucket
Hydrology Module
P
Plant
Canopy
Et= f(z1,kc, , PET)
Pe = f(P, Snow Accum,
Melt rate)
u
z1
Rd
Sw
L
Surface Runoff =
f(Pe,z1,1/LAI)
Interflow =
f(z1,ks, 1-f)
Percolation =
f(z1,ks,f)
Smax
z2
Dw
Baseflow =
f(z2,drainage_rate)
One 2-Bucket Model
per Land Class
Integrated Hydrology/Water
Management Analytical Framework in
WEAP21
Data Requirements: Demand

Water demand data: multi-sectoral

Municipal and industrial demand
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Agricultural demands
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Aggregated by sector (manufacturing, tourism,
etc.)
Disaggregated by population (e.g., use/capita,
use/socioeconomic group)
Aggregated by area (# hectares, annual wateruse/hectare)
Disaggregated by crop water requirements
Ecosystem demands (in-stream flow
requirements)
Data Requirements (continued)
SECTOR
SUBSECTOR
END-USE
DEVICE
Agriculture
Cotton
Rice
Wheat
...
Irrigation
...
Furrow
Sprinkler
Drip
Industry
Electric Power
Petroleum
Paper
...
Cooling
Processing
Others
Standard
Efficient
...
Municipal
South City
West City
...
Single Family
Multi-family
...
Kitchen
Bathing
Washer
Toilet
...
Example Data Resources

Indigenous knowledge!

Climate
www.apdrc.soest.hawaii.edu
(Asia Pacific Data Research Center)

Hydrology
www.grdc.bafg.de
(Global Runoff Data Center)

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
GIS
www.asian.gu.edu/au
(Asian Spatial Information and Analysis Network)
General Resources
www.weap21.org
Calibration and Validation

Model evaluation criteria
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Flows along mainstem and tributaries
Reservoir storage and release
Water diversions from other basins
Agricultural water demand and delivery
Municipal and industrial water demands and
deliveries
Groundwater storage trends and levels
Modeling Streamflow
Looking at Results
Select results to be
viewed, including
which scenario here.
Change units
and sub
categories of
results, and
change the
style of the
graph here.
Select values
for the y
here.
What next?

How can output from WEAP, or any water
resource model for that matter, be organized
and analyzed to select adaptation
strategies?...
Stakeholder-driven multi-criteria analysis can
help…
Multi-criteria Analysis (MCA)


Any structured approach used to determine
overall preferences among alternative
options, where the alternatives can
accomplish several objectives
Is particularly useful to situations where a
single criterion would fall short, and allows
decision-makers to address a range of
relevant factors
MCA: Scope


All sectors, regions, livelihoods, ecosystems,
etc.
Has been used extensively in water
resources planning, coastal zone
management, agricultural development, and
stakeholder processes
MCA: Key Outputs

A single preferred option, or…

A short list of preferred options, or…

A characterization of acceptable and
unacceptable possiblities
MCA: Key Inputs

Evaluation criteria

Relevant metrics for those criteria
MCA–WEAP: Motivation

Develop an interactive computer tool to
facilitate multi-criteria assessment for water
resource options in a stakeholder context

Designed specifically to be used in
conjunction with outputs from the WEAP
model and stakeholder processes to
develop, weight and apply evaluation criteria
to adaptation options
MCA–WEAP: History

MCA-WEAP is a new Excel macros-based model, built off
of NAPAssess, a tool developed by SEI for use by Sudan
and Yemen in their NAPA processes

Now reshaped to focus exclusively on adaptation options
around water – used so far in Netherlands Climate
Assistance Program (NCAP) studies





ensure adequate stakeholder representation
Identify CC adaptation strategies
establish country-driven criteria to evaluate and prioritize
Make concensus-based recommendations for adaptation
initiatives
Open source, and still a BETA version!
MCA–WEAP: Capabilities

Streamlines the multi-criteria analysis
process by:

Housing all relevant project information on a
single platform

Supporting a transparent, user-friendly
process for developing, weighting, and
applying evaluation criteria

Producing a ranked set of alternatives
MCA–WEAP: Steps






Assess vulnerability priorities
Identify key stakeholders
Identify potential adaptation strategies
Develop stakeholder-driven evaluation
criteria to determine trade-offs
Assign weights to criteria
Prioritize adaptation options for best meeting
the needs of those most vulnerable
Licensing WEAP


Go to www.weap21.org and register for a
new license (free for government, university,
and non-profit organizations in developing
countries)
Register WEAP under Help menu and select
“Register WEAP”