National Water Census Apalachicola-Chattahoochee-Flint River Basin Focus Area Study: Surface water modeling component May 12, 2014

Jacob LaFontaine

U.S. Department of the Interior U.S. Geological Survey

Hydrologic modeling in the ACFB

SERAP Flint River Science Thrust Project

2006 2009 2012

USGS Water Census

Hydrologic modeling goals • Simulate water budget

for entire basin at a ‘coarse’ scale (HUC 12) for the National Water Census

• Simulate streamflow in six subbasins at a ‘finer’ scale for ecological team

• Study effects of climate, land cover, and water use

Hydrologic modeling tasks

• Update existing models through 2012

Hydrologic modeling tasks

• Update existing models through 2012

• Develop water use module for PRMS

Hydrologic modeling tasks

• Update existing models through 2012

• Develop water use module for PRMS

• Incorporate water use into PRMS models

Hydrologic modeling tasks

• Update existing models through 2012

• Develop water use module for PRMS

• Incorporate water use into PRMS models

• Link PRMS to MODFLOW

Hydrologic modeling tasks

• Update existing models through 2012

• Develop water use module for PRMS

• Incorporate water use into PRMS models

• Link PRMS to MODFLOW

• Provide output to Ecology team and NWC

Biologically relevant streamflow statistics

Update existing hydrologic models • Models simulated ‘no-water-

use’ flows for 1951 to 1999.

• Used gridded inputs of air temperature and precipitation

• Update to simulate ‘no-water-use’ flows through 2012 using weather station data (NCDC)

Water use module • Sources of water:

– Streams – Groundwater reservoir – Surface water bodies – External

• Destinations of water:

– Streams – Groundwater reservoir – Surface water bodies – External – Land surface application – Consumption

Incorporating water use • Map water withdrawals and

returns to modeling units – Municipal & Industrial – Agricultural

• Extract water use data from

SWUDS – Monthly time series

• Construct water-use input files

– Automate for future applications

Link PRMS to MODFLOW • Not GSFLOW due to available

time and resources

• Loose coupling (PRMS) – Surface runoff and

interflow simulated by PRMS

– Recharge to MODFLOW simulated by PRMS

PRMS

Recharge to groundwater system

Surface runoff

Interflow

Link PRMS to MODFLOW • Loose coupling (MODFLOW)

– MODFLOW uses PRMS

generated recharge

– Simulates groundwater component of streamflow

Recharge from PRMS

Input to MODFLOW

Groundwater flow to streams

Link PRMS to MODFLOW • Loose coupling (Routing)

– Post process streamflow

using flow components from each model

– Surface runoff and interflow from PRMS

– Groundwater flow from MODFLOW

– Muskingum routing

Groundwater flow to streams

Surface runoff

Interflow

Streamflow

+

+

+ In-stream water use

Products of this study • Water Budget and streamflow

information

• Documented PRMS models for use in future studies

• Loose coupling methodology for SW/GW

• Expanded capabilities of PRMS to incorporate water use data

• Improved understanding of effects of climate, land cover, and water use on streamflow in the ACFB

Upcoming PRMS enhancements • Improved simulation of

surface-depression storage features

• Dynamic parameters

• Combined stream and lake routing

• Stream temperature

• National Hydrologic Model

USGS National Research Program

Modeling of Watershed

Systems

Questions?