1. 1 One-month Stress Period Considerations Presentation to ESHMC 8 January 2008 B. Contor

2. Courtesy Rick Raymondi

3. Outline MODFLOW & PEST considerations Recharge tool considerations Data considerations

4. MODFLOW & PEST considerations 1. Meaning of “Stress Period”

5. MODFLOW & PEST considerations 2. Meaning of “Time Step”

6. MODFLOW & PEST considerations 3. Observations occur when they occur

7. MODFLOW & PEST considerations 4.Model output is interpolated to times of observations

8. MODFLOW & PEST considerations 5. Match is calculated at the time the observation occurred

9. Something to think about: MODFLOW Aquifer Parameters PEST ESPAM 1.X Process MODFLOW Aquifer Parameters FORTRAN Rech. Tool Recharge Parameters ESPAM 2.0 Process?

10. Something to think about: MODFLOW ~ 200 Aquifer Parameters ESPAM 1.X Process runtime w/ 44 stress periods: a few seconds PEST Total PEST runtime about 12 hrs.

11. Something to think about: runtime w/ 324 stress periods: ??? Total PEST runtime ???? MODFLOW ??? Aquifer Parameters FORTRAN Rech. Tool ??? Recharge Parameters ESPAM 2.0 Process? runtime w/ 324 stress periods: ??? runtime w/ 44 stress periods: a few minutes

12. Overview of Recharge Tool

13. Review of Recharge Tool GIS tool –ArcGIS 8.x or 9.x –GW Modeling Toolbar (ArcGIS extension) –ESPAM.exe FORTRAN tool –Readinp.exe

14. Review of Recharge Tool GIS tool –ArcGIS 8.x or 9.x –GW Modeling Toolbar –ESPAM.exe FORTRAN tool –Readinp.exe Data handling Calculations

15. Input Data GIS Points GIS Lines GIS Polygons GIS Rasters Tables GIS Tool Model Grid Output Tables in Specific Format Start Creating Output Tables (Stolen from May Training slides)

16. Output files Created by GIS Tool.mdl - simulation and scenario information.cel - model grid information.pch - perched reaches.trb - tributary underflow.cnl - canal seepage data.sol - soils.pre - precipitation.div - diversions and returns.fpt - fixed point sources and withdrawals.off - offsite ground water pumping.ent - irrigation entities.iar - irrigated agriculture.eti - irrigated lands evapotranspiration.red - irrigation discount table.nir - recharge on non- irrigated lands.spt - scenario sources and withdrawals (Stolen from May Training slides)

17. GIS tool explicitly represents every stress period:.pch - perched reaches.trb - tributary underflow.cnl - canal seepage data.pre - precipitation.div - diversions and returns.fpt - fixed point sources and withdrawals.off - offsite ground water pumping.iar - irrigated agriculture.eti - irrigated lands evapotranspiration.red - irrigation discount table.nir - recharge on non- irrigated lands.spt - scenario sources and withdrawals

18. GIS tool uses single representation for entire simulation:.mdl - simulation and scenario information.cel - model grid information.ent - irrigation entities.sol - soils data

19. .pch - perched reaches.pre - precipitation.div - diversions and returns*.fpt - fixed point sources and withdrawals.off - offsite ground water pumping.eti - irrigated lands evapotranspiration.spt - scenario sources and withdrawals Native data frequency is one month or better * interpolation will be required for a few small entities

20. Data frequency longer than one month but this matches physical reality.mdl - simulation and scenario information.cel - model grid information.sol - soils.iar - irrigated agriculture.red - irrigation discount table.cnl - canal seepage data*.ent - entity data * maybe

21. Data frequency is longer than one month, adjustment may be needed.trb - tributary underflow.nir - recharge and non- irrigated lands

22. END Courtesy Rick Allen