InVEST freshwater models

Fisheries Aquaculture Coastal Protection Recreation Wave Energy Habitat Risk Asst Aesthetic Quality Water Quality Water purification Sediment retention Crop pollination Hydropower Irrigation water NTFP Flood control Commercial timber Biodiversity Carbon sequ’n Agricultural prod’n Coastal / marine Terrestrial / freshwater

Invest Hydropower 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 Volume Hydropower and Valuation Model Dam Height Price EnergyEnergy Value Turbine Eff. E(t) P(t) Q(t) Water Yield Model Land Use Soils Climate Water Yield Evapo- transpiration

Precipitation Rain Snow Fog Inflow Contributing Pixel ET o WATER YIELD

Precipitation Rain Snow Fog Inflow Transpiration WATER YIELD

Precipitation Rain Snow Fog Inflow Transpiration Root depth Water Availability Leaf type Seasonality Plant type WATER YIELD

Precipitation Rain Snow Fog Inflow Transpiration Root depth Water Availability Leaf type Seasonality Plant type Evaporation WATER YIELD

Precipitation Rain Snow Fog Inflow Transpiration Root depth Water Availability Leaf type Seasonality Plant type Evaporation annual average water yield per pixel Y jx 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 Consumption Consumptive Use Temporal dynamics Reservoir Design. Factors Affecting Hydropower?

Model Inputs Land Use/Land Cover Root depth, evapotranspiration coefficient Climate Precipitation, PET Soils Soil depth, PAWC Watersheds Main and sub-watersheds for point of interest Economic Hydropower 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 V in = Y - u d

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

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 Virungas Belize 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) I f (t) P(t) I(t) S m (t) B f (t) Q f (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 Transpiration Root depth Water Availability Leaf type Seasonality Plant type Evaporation annual average water yield per pixel Y jx

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 ) E(t) P(t) Q(t)

Energy Calculation p d = d.q d.g.h d water density gravity constant outflow rate head outflow

Valuation  Total Value of the Hydropower:  The Sub-basin’s Hydropower production Value:

Data Requirements InputsProcessOutputs

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