Land-use forecasting and hydrologic model integration for improved land-use decision support

Area of Science:

• Environmental Hydrology
• Geographic Information Systems (GIS)
• Land Use Planning

Background:

• Watershed management requires understanding land-use impacts on hydrology.
• Forecasting future land-use change is crucial for effective policy.
• Integrating predictive models can enhance watershed-scale decision-making.

Purpose of the Study:

• To develop and demonstrate a methodology for integrating land-use forecasting and rainfall-runoff models.
• To support land-use policy formulation at the watershed scale.
• To quantify the hydrologic implications of forecasted land-use changes.

Main Methods:

• Loosely coupled integration of the What If? land-use model and the HEC-HMS hydrologic model on a common GIS platform.
• HEC-HMS model calibration for a specific storm event in central Washington State.
• Forecasting land-use distributions (low-density residential) for 2015, 2025, and 2050 under varying population growth scenarios.

Main Results:

• Forecasted land-use patterns were used as input for the calibrated HEC-HMS model.
• Predicted changes in stream discharge hydrographs due to increasing development.
• Demonstrated synergy between the integrated land-use and hydrologic models.

Conclusions:

• The integrated modeling approach provides a valuable tool for land-use decision-makers.
• Quantifiable forecasting of hydrologic impacts enables informed policy selection.
• This methodology helps identify land-use alternatives that effectively minimize stormwater runoff.