Decision Tools to Evaluate Vulnerabilities and Adaptation Strategies to Climate Change

Water Resources Sector

Sebastián VicuñaUniversity of California, Berkeley/SEI

CGE Hands-on Training Workshop on V&A Assessments for the Latin America and the Caribbean Region

Asunción, Paraguay, 14-18 August 2006

Outline

Vulnerability and adaptation with respect to water resources

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 Often V&A in the water sector focuses on

analysis over assessment Why? Because the focus is on biophysical

impacts, e.g., hydrologic response, crop yields, land use, etc.

Assessment is an integrating process requiring the interface of physical and social science and public policy

Effective V&A Assessments (continued)

General questions 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

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)

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

Water quantityWater quality

Seasonality of flowRegulation

Water for agriculture

Domestic water

Water for industry

Water for nature

Water for recreation

The Water Resource SectorWater’s “Trade-Off” Landscape

Water Resources from a Services Perspective

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

Water Resources – A Critical V&A Sector

Must consider both managed and natural systems

Human activity influences both systems

Natural Systems

External Pressure

State of System

Little Control of processes

ManagedSystemsExternal

Pressure Product, good or service

Process Control

Example: Agriculture Example: Wetlands

services

Hydrologic ‘External Pressures’ related to Climate Change

Precipitation amount Global average increase Marked regional differences

Temperature increase Change in timing of streamflows Glacier retreat

Precipitation frequency and intensity Less frequent, more intense (Trenberth et al., 2003)

Evaporation and transpiration Increase total evaporation Regional complexities due to plant/atmosphere

interactions

Specific Pressures: Annual Runoff

Arnell., 2003

Change in annual runoff (A2 scenario)

Specific Pressures: Annual Runoff

Arnell., 2003

Change in annual runoff (A2 scenario)

Change in annual runoff (A2 scenario)

Specific Pressures: Annual Runoff

Specific Pressures: Runoff timing, analogy to North American West

Stewart et al., 2004

Analogy with Western North America

http://plasma.nationalgeographic.com/mapmachine/index.html

Analogy with Western North America

http://plasma.nationalgeographic.com/mapmachine/index.html

Specific Pressures: Runoff timing, analogy to North American West

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250

OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP

Infl

ow

an

d D

eman

ds

(TA

F)

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1250

Reservo

ir storag

e (TA

F)

Historic Inf low PCMA1fi Demand Reservoir Storage

Inflow spilled

Refill lost

Specific Pressures: Retreating glaciers

Comunicación Nacional del Perú a la UNFCCCFrancou et al., 2000

Retroceso del glaciar BroggiGlaciar en 1979 y 1997

Fluctuación del frente de 4 glaciares en Perú

Evolución del glaciar Chacaltaya (Bolivia)

Specific Pressures: Retreating glaciers

Meltwaters are depended upon during dry season to sustain low flow periods

Probable diminished volume and earlier timing of flows Has implications for hydropower production, agricultural

demands, and river and riparian quality and ecosystem needs

Specific Pressures: Extreme weather

Climate variability (El Nino/Nina Southern Oscillation) impact water availability and all economic sectors en several countries in the region (e.g. Peru, Ecuador, Central America) (IPCC 2001).

Some climate models indicate more El Nino-like climate with increased greenhouse gases concentrations (Meehl and Washington 1996; Trenberth and Hoar, 1997)

Specific Pressures: Extreme weather

Arnell., 2003

Change in extremes by the 2050s, under HadCM3

Specific Pressures: Extreme weather

Arnell., 1999

Change in extremes by the 2050s, under HadCM3

Examples of Adaptation in Water Resources

Construction/modification of physical infrastructure 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)

Adaptive management of existing water supply systems Change operating rules for reservoirs Use conjunctive surface/groundwater supply Physically integrate reservoir operation

system Coordinate supply/demand Indigenous options

Examples of Adaptation in Water Resources (continued)

Policy, conservation, efficiency, and technology Domestic

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 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)

Policy, conservation, efficiency, and technology (continued)

Industry Water re-use and recycling Closed cycle and/or air cooling More efficient hydropower turbines Cooling ponds, wet towers and dry towers

Energy (hydropower) 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

What tools are available to understand both water resource vulnerabilities and evaluate possible adaptation strategies?

How can stakeholders be engaged in these processes?

Types of Water Resources Models

Hydraulic: biophysical process models describing streamflow, flooding

Hydrology: rainfall/runoff processes

Planning: water resource systems models

Which model?...What questions are you trying to answer?

Hydraulic Model

Critical questions How fast, deep is river flowing (flooding effects) How do changes to flow and channel morphology

impact sediment transport and services provided (fish habitats, recreation, etc).

Hydrology Model

Critical questions 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 Critical questions

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?

Operational and hydraulic HEC

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 MIKE11Delft3d

Tools to Use for the Assessment: Referenced Water Models

Hydraulic Water Management Model

HEC-HMS watershed scale, event based hydrologic simulation, of rainfall-runoff processes

Sub-daily rainfall-runoff processes of small catchments

Free, download from web

Tools to Use for the Assessment: Referenced Water Models (continued)

Planning/ hydrology

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)… Aquarius SWAT (Soil Water Assessment Tool) WEAP21 (Water Evaluation and Planning)

Physical Hydrology and Water Management Models

AQUARIUS advantage: Has economic efficiency criterion requiring the reallocation of stream flows until the net marginal return in all water uses is equal

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.

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

Can be climatically driven Based on holistic approach

of integrated water resources management (IWRM) – supply and demand

Overview WEAP21

Hydrology and planningPlanning (water distribution) examples and exercisesAdding hydrology to the modelUser interfaceScaleData requirements and resourcesCalibration and validationResultsScenariosLicensing and registration

You can create multiple scenarios and use this box to switch between them.

Use the View bar to switch between your analysis and its results.

Data are organized in a tree structure that you edit by right-clicking here.

Your data are shown here as either a graph or a table.

Enter or edit your data by typing it here.

WEAP and Planning

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

Uses of WEAP

Policy Research Alternative Allocations Climate Change Land Use Change Infrastructure Planning

Capacity Building Negotiation Stakeholder Engagement

WEAP Capabilities

Can doHigh level planning at local and regional scalesDemand managementWater allocationInfrastructure evaluation

Cannot doSub-daily operationsOptimization of supply and demand (e.g. cost minimizations or social welfare maximization)

A Simple System with WEAP21

60

40

An Infrastructure Constraint

70

3010 Unmet

A Regulatory Constraint

70

3010 Unmet

IFR Met

0

40

60

10 unmet

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

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Different Preferences

For example, a center pivot operator may prefer to take water from a tributary because of lower pumping costs

WEAP is Scenario-driven

The scenario editor readily accommodates analysis of: Climate change scenarios and assumptions Future demand assumptions Future watershed development assumptions

Futures and Scenarios: Why? 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

Economic

•Growing integration of global economy

Social

•Increasing inequality•Persistent poverty

Cultural•Spread of values of consumerism and individualism

•Nationalist and religious reaction

Technological

•Computer and information technology•Biotechnology•Miniaturization

Environmental/Climatic

•Increasing global stress

•Local degradation

•Some remediation in richer countries

Governance•Global institutions

•Democratic government•Role for civil society in decision-making

Who are the Actors?

Government Private sector Civil society Public

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 DefinitionSpatia l Boundary System C om ponentsT im e H orizon N etwork C onfiguration

EvaluationW ater Suffic iency Ecosystem R equirem entsPollu tant Loadings Sensitiv ity Analysis

Current AccountsD em and Pollu tant G enerationR eservoir C haracteristics R esources and SuppliesR iver S im ulation W astewater T reatm ent

ScenariosD em ographic and Econom ic Activ ityPatterns of W ater U se, Pollu tion G enerationW ater System InfrastructureH ydropowerA llocation, P ric ing and Environm ental PolicyC om ponent C ostsH ydrology

WEAP21 Program Structure

You can click and drag elements of the water system from the legend onto the schematic directly.

Use the menu to do standard functions such as creating new areas and saving.

Your can zoom your schematic in or out by sliding the bar here.

GIS layers can be added here.

Use the View bar to switch between your data and its results.

The WEAP21 Graphical User Interface

Languages:

Interface Only

English

French

Chinese

Spanish

You can create multiple scenarios and use this box to switch between them.

Use the View bar to switch between your analysis and its results.

Data are organized in a tree structure that you edit by right-clicking here.

Your data are shown here as either a graph or a table.

Enter or edit your data by typing it here.

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

Area, land cover . . . Climate

Precipitation, temperature, windspeed, and relative humidity

User-defined Streamflows and Demands

Letting Climate Drive Hydrology

The WEAP 2-Bucket Hydrology Module

Smax

Rd z1

Interflow = f(z1,ks, 1-f)

Percolation = f(z1,ks,f)

Baseflow = f(z2,drainage_rate)

Et= f(z1,kc, , PET)

Pe = f(P, Snow Accum, Melt rate)

Plant Canopy

P

z2

L

u

Surface Runoff =f(Pe,z1,1/LAI)

Sw

Dw

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

Aggregated by sector (manufacturing, tourism, etc.)

Disaggregated by population (e.g., use/capita, use/socioeconomic group)

Agricultural demands Aggregated by area (# hectares, annual water-

use/hectare) Disaggregated by crop water requirements

Ecosystem demands (in-stream flow requirements)

Data Requirements (continued)

Agriculture

Industry

Municipal

CottonRiceWheat...

Electric PowerPetroleumPaper...

South CityWest City...

Irrigation...

CoolingProcessingOthers

Single FamilyMulti-family...

FurrowSprinklerDrip

StandardEfficient...

KitchenBathingWasherToilet...

SECTOR SUBSECTOR END-USE DEVICE

Example Data Resources

Indigenous knowledge!

Climatehttp://www.ncdc.noaa.gov/cgi-bin/res40.plhttp://ingrid.ldgo.columbia.edu/SOURCES/.NOAA/.NCDC/.GCPS/.MONTHLY/.STATION/

Hydrology (Global Runoff Data Center)www.grdc.bafg.de

GIShttp://data.geocomm.com/catalog/

General Resourceswww.weap21.org

Calibration and Validation

Model evaluation criteria 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 subcategories of results, and change the style of the graph here.

Select values for the yhere.

What next?

How can output from WEAP, or any water resource model for that matter, be organized and analyzed to prioritize and select appropriate 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 of 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 consensus-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 key vulnerability 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”