1 / 28

Community Hydrologic Model: Structure

Community Hydrologic Model: Structure. Reed Maxwell LLNL. Challenges to CHM. Application: pore-scale groundwater contaminant transport to global hydrology Physics and scale: balance laws not scale invariant Computing: desktop to supercomputer

chenoa
Download Presentation

Community Hydrologic Model: Structure

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Community Hydrologic Model: Structure Reed Maxwell LLNL

  2. Challenges to CHM • Application: pore-scale groundwater contaminant transport to global hydrology • Physics and scale: balance laws not scale invariant • Computing: desktop to supercomputer • Calibration, Optimization: needs to be flexible to connect w/ management codes • User Communities: each with different needs, goals and perspectives

  3. Huge range in scales Regional Scale: 132x88x0.5km Dx=Dy=1km Dz=0.5m Plot Scale: 17x10x3.8m Dx=Dy=0.34m Dz=0.038m

  4. Timescales and scaling in Groundwater • Range of paths and scales in groundwater • Water moves as K/q~10-4-10-5 m/s • Pressure propagates as Kb/Ss~100-101 m/s • System responds over a wide range of scales (Kirchner et al 2000, 2001; Alley et al 2002) • Topography and land surface processes have strong influence Z (m) Land surface 0 20 40 Travel time (y) Kirchner et al (2000)

  5. Thoughts on Model Structure • Object oriented • Open source • Parallel with efficient solvers, linear scaling • Flexible grid options • Flexible physics options • Flexible input • Not in a vacuum: able to be coupled to other models, processes

  6. Open Source Programming Tools QGIS • an open source and free "Programmable Geographic Information System" • a mapping tool, a GIS modeling system, and a GIS application programming interface (API) all in one • a platform independent Open Source Geographic Information System that runs on Linux, Unix, Mac OSX, and Windows • libraries for raster and vector geospatial formats • Object relational database is handled using PostgreSQL • GRASS compatible Qt/C++ - tools for programming the interface and visualization

  7. PIHM GIS Interface

  8. ParFlow Structure TCL input script: Set database keys for simulation, any other manipulations. • pfrun command: • Executes parflow.tcl script • Write database (.pfidb) file • Set up parallel run parameters • Execute run script • run script: • Execute ParFlow using platform specific options • Port standard output to a file

  9. Model Input Structure • TCL/TK scripting language • All parameters input as keys using pfset command • Keys used to build a database that ParFlow uses • ParFlow executed by pfrun command • Since input file is a script may be run like a program

  10. SolidFile Geometry (input file) pfset GeomInput.Names "solidinput" pfset GeomInput.solidinput.InputType SolidFile pfset GeomInput.solidinput.GeomNames domain pfset GeomInput.solidinput.FileName fors2_hf.pfsol pfset Geom.domain.Patches "infiltration z-upper x-lower y-lower x-upper y-upper z-lower"

  11. Octree used to delineate geometries Source: Wikipedia

  12. SolidFile Geometry

  13. Overland (hillslope rills) and channel flow along 1d links defined from DEM data CATHY Model: Governing equations: channel and hillslope routing [Orlandini & Rosso, WRR 2001]: • "Constant critical support area": overland flow cells with upstream drainage area A < A*; else channel flow • Leopold & Maddock relationships; • Muskingum-Cunge solution scheme (explicit and sequential); etc • (need Pe and Cu1)

  14. Penn State Integrated Hydrologic Model: PIHM Qu and Duffy 2007

  15. ParFlow enables simulating groundwater flow in large subsurface regimes Ground Surface • Two Modes: fully and variably saturated (via Richards’ EQ) flow solver • Efficient multigrid preconditioned linear solver • Kinsol nonlinear solver • Parallel code specifically designed to run on large institutional computer facilities • Enables large, highly-resolved, simulations • Coupled overland flow and land surface interactions Infiltration Front Vadose Zone Saturated Zone Water Table Ashby and Falgout, 1996; Jones and Woodward, 2001; Kollet and Maxwell, 2006

  16. LSM LSM LSM LSM LSM LSM LSM LSM LSM LSM Coupled Model PF.CLM Atmospheric Forcing Land Surface Flow Divide • PF.CLM= Parflow (PF) + Common Land Model (CLM) Kollet and Maxwell (2008), Kollet and Maxwell (2006), Maxwell and Miller (2005), Dai et al. (2003), Jones and Woodward (2001); Ashby and Falgout (1996) • Surface and soil column/root zone hydrology calculated by PF (removed from CLM) • Overland flow/runoff handled by fully-coupled overland flow BC in PF (Kollet and Maxwell, AWR, 2006) • CLM is incorporated into PF as a module- fully coupled, fully mass conservative, fully parallel Air Root Zone Vadose Zone Vegetation Water Table Routed Water Flow Lines Groundwater Dynamically coupled, 2D/3D OF/LS/GW Model

  17. Integration of Atmospheric Processes – PF.ARPS • Understanding two-way feedbacks: subsurface  atmosphere • Integrate ARPS (Advanced Regional Prediction System) into ParFlow • ARPS (Xue et al., 1995, 2000, 2001): • Large eddy simulation code • solves the three-dimensional, compressible, non-hydrostatic Navier-Stokes equations • Land Surface Model: ISBA (Interaction Soil Biosphere Atmosphere)

  18. Scaled Parallel Efficiency Perfect efficiency: double problem size and processor # same run time => E = 1 Kollet and Maxwell, AWR (2006)

  19. Many options for subsurface conceptual model Loam Sand • Completely general, 3D subsurface variably saturated GW model • Any parameter combinations, effective, heterogeneous, stochastic • Many scales, features can be incorporated, no predefined GW or vadose zones Loamy Sand Clay Loam Soil Aquifer Aquitard/bedrock

  20. Conceptual Model + GeoDataBase = A Priori Data Conceptual Model Groundwater flow in the Allegheny Plateau Section. Example of the GIS for the surface geology coverage.

  21. Little Washita watershed in OK provides a good field site for coupled model • Site of several Southern Great Plains (SGP) field campaigns • Located at bottom Atmospheric Radiation Measurement (ARM) site • Most complete data set to validate model

  22. “Offline” Model Spinup and Dynamics • Run offline, PF.CLM coupled model • WY 1999 used as forcing (NARR) • Spinup: Run over successive years until beginning-ending water and energy balances drop below threshold • Results can be: • compared to data • used to understand dynamics • used for initialization Kollet and Maxwell (2008a)

  23. Water Table Depth, Cross Section • Water table driven by topography • Very deep (~40m) at hilltops (drier) • Very shallow in valleys (wetter) • Cross section shows variation of WT and Saturation hilltops valleys groundwater Maxwell, Chow and Kollet, AWR (2007)

  24. We see a connection between groundwater and the lower atmosphere 27h • Cross-section at y=15km • Shallow WT=wetter • Wetter=cooler • Temperature variations=wind variations • Wind variations=BL variations Maxwell, Chow and Kollet, AWR (2007)

  25. Vegetation effect: 15 Wm-2 Groundwater effect: 25 Wm-2 Influence of Groundwater Dynamics on Energy Fluxes (yearly averaged) Kollet and Maxwell (2008a)

  26. Understanding Residence Times: Spatiotemporal Scaling of Baseflow Contributions Kollet and Maxwell (2008b)

  27. Summary: CHyMP Model Structure • Object oriented • Flexible • Range of interface, data, needs • Range of Scales • Growing community of models, experiences • Interesting science questions

  28. CHyMP Model Challenges • Community • Intercomparison • Education • Data

More Related