InVEST freshwater models

Fisheries

Aquaculture

Coastal Protection

Recreation

Wave Energy

Habitat Risk Asst

Aesthetic Quality

Water Quality

Water purificationSediment retention

Crop pollination

Hydropower

Irrigation waterNTFP

Flood control

Commercial timber

BiodiversityCarbon sequ’n

Agricultural prod’n

Coastal / marineTerrestrial / freshwater

Invest 2.2.2Hydropower Production model

Yonas Ghile, Stacie Wolny and Nirmal Bhagabati

Water Yield for

Irrigation

Drinking Water

Hydropower

Pollution Dilution

Water Yield

Questions

How much water is available?

Where does the water used for

hydropower production come from?

How much energy does it produce?

How much is it worth?We have often used just the water yield part of the model,

without linking it to hydropower

Informing Policy Makers

Focus protection on areas that contribute the most.

Design management practices that lead to minimal loss.

Identify places where other economic activities will conflict

with water yield for hydropower production or other uses.

How much hydropower will we gain or lose under future

management or conservation plans?

Create payment programs to get most return on investment

(with Tier 2 model).

Again, can be used to assess water yield for non-hydropower uses as

well

This model does NOT assess impacts of hydropower facilities

Model Architecture

Water Scarcity Model

Consumptive Use Net

VolumeHydropower

and Valuation Model

Dam Height

Price

EnergyEnergy Value

TurbineEff.

E(t) P(t)

Q(t)

Water Yield

Model

Land Use Soils

Climate

Water YieldEvapo-

transpiration

Precipitation

Rain

Snow

Fog

Inflow

Contributing Pixel

ETo

WATER YIELD

Precipitation

Rain

Snow

Fog

Inflow

Transpiration

WATER YIELD

Precipitation

Rain

Snow

Fog

Inflow

Transpiration

Roo

t dep

th

Water Availability

Leaf type

SeasonalityPlant type

WATER YIELD

Precipitation

Rain

Snow

Fog

Inflow

Transpiration

Roo

t dep

th

Water Availability

Leaf type

SeasonalityPlant type

Evaporation

WATER YIELD

Precipitation

Rain

Snow

Fog

Inflow

Transpiration

Roo

t dep

th

Water Availability

Leaf type

SeasonalityPlant type

Evaporation

annual average water yield per pixel

Yjx

WATER YIELD

• Water Yield is the water depth (volume) that is NOT Evapotranspired.

• It is the sum of Surface flow, subsurface flow and groundwater flow.

WATER YIELD

• Water yield by itself not an ecosystem service, but becomes a service where there is demand for it, e.g., for hydropower generation, municipal consumption, irrigation etc.

• Rainfall,

• Evaporation,

• Land Use and Land Cover,

• Soil,

• Water Consumption

• Temporal dynamics

•Reservoir Design.

Factors Affecting Hydropower?

• Rainfall,

• Evaporation,WATER YIELD

• Land Use and Land Cover,

• Soil,

• Water Consumption

• Time,

•Reservoir Design.

Factors Affecting Hydropower?

• Rainfall,

• Evaporation,WATER YIELD

• Land Use and Land Cover,

• Soil,

• Water ConsumptionConsumptive Use

• Temporal dynamics

•Reservoir Design.

Factors Affecting Hydropower?

Model Inputs

Land Use/Land CoverRoot depth, evapotranspiration coefficient

ClimatePrecipitation, PET

SoilsSoil depth, PAWC

WatershedsMain and sub-watersheds for point of interest

EconomicHydropower plant data, price of energy$$

Water demand

MAIN DATA INPUTS

• Rainfall

• Potential Evapotranspiration

• Soil: depth and Fraction of Available Water Content

• Land Use Land Cover: Crop Coefficients, Root Depth

• Consumptive water use by farms, towns etc

• Reservoir: Effective Head, Life time, Turbine efficiency, fraction, price of electric power, maintenance costs etc

Irrigation

Urban Consumption

Irrigation

Consumptive Use

Urban Consumption

Irrigation

Urban Consumption

Irrigation

Consumptive Use

Urban Consumption

water yield available for hydropower production

Vin = Y - ud

$####.##

Valuation

Model Strengths

Uses readily available and minimum data.

Simple, applicable and generalizable

Spatially explicit

Link the biophysical functions to economic values

Values each parcel on the landscape

Model Limitations

Neglects extremes and seasonal variation of water yield

Neglects surface-deep groundwater interactions

Assumes hydropower production and pricing remain constant

Calibration and Validation

Sensitivity Analysis to identify most sensitive parameters

Model Calibration using long term average actual data

Find land use parameters within acceptable ranges

Model parameter (Zhang constant)

Validate Model by conducting comparisons with observed data or

other model output

Model Outputs

Actual Evapotranspiration Per sub-watershed

Water yield Per sub-watershed

Energy/value for hydropower Per sub-watershed

Water supply Per sub-watershed Used in valuation

Testing and validation

InVEST vs SWAT

Comparison of SWAT and InVESTAverage annual water yield (mm)

TULUASWAT InVEST % difference

Baseline 805.98 804.28 0.21%No conservation 816.04 765.98 6.13%Conservation 805.54 768.87 4.55%

FRAILESWAT InVEST % difference

Baseline 301.23 379.19 -25.88%No conservation 319.77 335.54 -4.93%Conservation 300.55 362.60 -20.65%

Hainan Island China

R² = 0.97

Central Sumatra, Indonesia: Water yield in 2008, and percent change under two scenarios

(a) Water yield in 2008 (b) Percent change in water yield from 2008 to Vision

(c) Percent change in water yield from 2008 to plan

And Many Other Sites

China

Tanzania

West Coast

Hawai’i

Amazon Basin

Mexico Colombia

Ecuador Indonesia

VirungasBelize

East Coast

Coming up in InVEST

Regionalizing the Zhang constant

Automating calibration technique

Monthly model

Groundwater recharge index

Tier 2 water yield model

Irr(t)

E(t)

If(t)

P(t)I(t)

Sm(t)

Bf(t)

Qf(t)

S(t)

Point to discuss

• Where to get data?

• Getting relevant expert input – consult hydrologists / water resource experts

• How to do valuation? – Is InVEST valuation model appropriate?– If not, how to value? (e.g., municipal

supply, irrigation)• Validation and ground-truthing of

model outputs

Hands-on Session

Run the water yield model

Hands-on Session

Run the water scarcity model

Hands-on Session

Run the hydropower and valuation model

Hands-on Session

Think how you would use the Water Yield Model in your work?

Water Yield

Precipitation

Rain

Snow

Fog

Inflow

TranspirationR

oot d

epth

Water Availability

Leaf type

SeasonalityPlant type

Evaporation

annual average water yield per pixel

Yjx

How Does it Work?

Water Yield is the water depth (volume) that is NOT Evapotranspired: WY = P – AET

It is the sum of Surface flow, subsurface flow and groundwater flow: WY = SR + SubSR + GW

Model: WY = P * (1 – AET / P )

xjxjx

xjx

x

xj

RR

R

P

AET1

1

1

x

xx P

AWCZhang

x

xxj P

ETokcR

E(t) P(t)

Q(t)

Energy Calculation

pd = d.qd.g.hd

water densitygravity constant

outflow ratehead

outflow

=0.00272

Valuation

Total Value of the Hydropower:

The Sub-basin’s Hydropower production Value:

1

0 1

1T

ttdded

rTCpNPVH

=

Data Requirements

Inputs Process Outputs

•Focus protection on areas that contribute the most.

•Design management practices that lead to minimal loss.

•Create payment programs to get most return on investment.

•Identify places where other economic activities will conflict with hydropower production.

•Who provides this service?

•How much hydropower will we gain or lose under future management or conservation plans?

Hydropower Production

UPYRB Example

MAIN DATA INPUTS• Rainfall

• Potential Evapotranspiration

• Soil: depth and Fraction of Available Water Content

• Land Use Land Cover: Crop Coefficients, Root Depth

• Consumptive water use by farms, towns etc

• Reservoir: Effective Head, Life time, Turbine efficiency, fraction, price of electric power, maintenance costs etc