1. SGMA Climate Change Desktop tools for IWFM and Modflow
Craig Cooledge
Water Resources Engineer
Jacobs Engineering
CWEMF Annual Meeting
April 23rd 2019

2. Introduction

3. DWR-Provided Information
DWR Climate Change Analysis Background
WSIP Datasets:

4. Development of Projected Water Budgets
23 CCR § (e) Each Plan shall rely on the best available information and best available science to quantify the water budget for the basin in order to provide an understanding of historical and projected hydrology, water demand, water supply, land use, population, climate change, sea level rise, groundwater and surface water interaction, and subsurface groundwater flow.

5. Climate Data and Tools
VIC gridded change factors for precipitation and reference evapotranspiration
Monthly timeseries dataset from 1915 – 2011
Desktop tools for IWFM and MODFLOW based models to facilitate processing of climate data provided by DWR

6. Data available on SGMA Data Viewer

7. Methodology

8. Projected Water Budget Development with a Numerical Model

9. IWFM and MODFLOW Desktop Tools – Climate Change Data Processing
ArcGIS Toolbox based tools
Relates VIC grid to MODFLOW Grid/IWFM elements, small watersheds, or other regions
Project historic data under future climate scenarios
Produces MODFLOW/IWFM input files for climate change scenario simulations

10. Tool Showcase

11. Tool #1: Establish working directory and input data for IWFM model
IWFM Tool
Tools are executed in ArcCatalog or ArcMap
Documentation provided with tool describing input requirements and tool execution
Tool #1: Establish working directory and input data for IWFM model
Tool #2: Relate IWFM Model to VIC Model and Perturb Historic Input Data

12. Tool #2
IWFM Tool Snapshots
Tool #1

13. IWFM Input Data Development Considerations
ET data can be aggregated spatially and temporally
Compute time-varying ET based on based on repeating pattern of input data (IWFM 4000 Flag)
May require additional GIS attributes or lookup tables to relate data spatially
Projected Small Watersheds Data
Single dataset can be processed for elements and small watersheds

14. Tool #1: Establish working directory and input data for MODFLOW model
MODFLOW Tool
Tools are executed in ArcCatalog or ArcMap
Documentation provided with tool describing input requirements and tool execution
Tool #1: Establish working directory and input data for MODFLOW model
Tool #2: Relate MODFLOW Model to VIC Model and Perturb Historic Input Data

15. MODFLOW Tool Snapshots

16. MODFLOW Input Data Development Considerations
Model Arrays Require Specific File Naming Convention
Tool determines Month and Year based on filename
Model Array File Delimiter
Tool will decipher the delimiter that is used (space, comma, etc.)
Needs to be consistent throughout all files
Should be consistent with MODFLOW friendly formats

17. Additional desktop tools

18. Streamflow Change Factor Correction Tool
Spreadsheet tool to assist in perturbing basin unimpaired streamflow under climate conditions
2nd order correction calculation to ensure monthly timing and annual pattern of streamflow hydrograph is consistent with climate change simulations

19. CalSim II to C2VSim Diversion Lookup
Effort to map CalSim II Diversions to C2VSim Diversions
Incorporate changes in deliveries based on CVP/SWP system operations under projected hydrology
Released in the near future

20. Other Related DWR Modeling Tools
DWR SGMA Resources
SGMA Data and Tools:
SGMA Climate Change Resources:
Climate Change Documentation:
Other Related DWR Modeling Tools
IWFM:
C2VSim:
SVSIM:

21. Thank you!
Craig Cooledge Water Resources Engineer Jacobs Engineering
Tyler Hatch, PhD, PE
Senior Engineer, Water Resources
Sustainable Groundwater Management Program

22. Follow DWR on social media
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