Water Supply Stress Index (WaSSI) Ecosystem Services Model

Model Functionality and Use:

Peter Caldwell, [email protected]

Technical Issues:

Erika Cohen, [email protected] 

Jennifer Moore Myers, [email protected]

Posted on: 8/01/2017 - Updated on: 1/19/2024

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The Water Supply Stress Index (WaSSI) Ecosystem Services Model is an online tool that models potential impacts of climate change, land use change and water consumption alteration (i.e., population growth and water withdrawals) on flow volumes, water supply stress, and ecosystem productivity. The WaSSI Ecosystem Services Model can be used technically to model impacts in the United States, Mexico, Rwanda, and Burundi, but can also serve as an educational tool to demonstrate linkages between water use, climate change, water availability, and carbon storage. The WaSSI Model allows for high levels of customization and interaction. Users can define model areas (by country), explore technical simulation input data, define various climate projections, time scales, land use changes, and water use changes for simulation analysis, and view and download simulation results. Both input data and output data can be viewed numerically, graphically, and spatially, and downloaded for later use. The WaSSI Model allows comparative analyses of different scenarios, which can be useful when looking at management tradeoffs related to ecosystem services (i.e., water yield and carbon sequestration), as well as during planning and adaptation efforts. For optimum use of the WaSSI Model, modelers suggest using Mozilla Firefox or Internet Explorer 8 and higher.

Example in use: The WaSSI Ecosystem Services Model was used by the USDA Forest Service in the Southern Forest Futures Project, which characterized major drivers for forest health and change across 13 southeastern states. The WaSSI model was used to examine how water stress, streamflow changes, and water supply may change under different climate and land use scenarios, helping to inform sustainable and resilient forest management.

Phase of Adaptation: Assessment, Planning


Natural resource managers, researchers, educators, public, local/state/regional planners and policymakers

Managing Organizations

The U.S. Department of Agriculture Forest Service is a Federal agency that manages public lands in national forests and grasslands. The Forest Service is also the largest forestry research organization in the world, and provides technical and financial assistance to state and private forestry agencies. Gifford Pinchot, the first Chief of the Forest Service, summed up the purpose of the Forest Service—"to provide the greatest amount of good for the greatest amount of people in the long run."


Target Climate Changes and Impacts