Distributed Hydrological Modeling and the Emerging WRF-Hydro Framework

Transcription

1 Distributed Hydrological Modeling and the Emerging WRF-Hydro Framework David J. Gochis Research Applications Laboratory National Center for Atmospheric Research Boulder, CO USA

2 Existing or Recently Proposed WRF-Hydro ( Noah -based) Implementations Past or current implementations Recently proposed implementations

3 3. Supporting Distributed Hydrological Modeling: DEM: 100 m Water table depth (m) Soil moisture Stream channel inflows Northern Alps : Germany Domain: ~140x220 km Are fine-scale hydrologic processes important to the atmosphere?

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5 Noah/Noah-MP DHSVM (Wigmosta) HSB (Troch) CATHY (Niu) tribs (Vivoni) CLM-CWRF (Choi, Liang, Kumar) PARFLOW (Maxwell, Kollet) LEAF (Miguez- Macho) VIC (Liang, Wood, Lett)

6 The WRF-Hydro model Pathway Forward: Linking multi-scale process models in a consistent and easily extensible modeling framework Existing NWP/reg. climate models Conceptualization of nature

7 Scale and process issues: Terrain features affecting moisture availability (scales ~1km) Routing processes: the redistribution of terrestrial water across sloping terrain Overland lateral flow (dominates in semi-arid climates) Subsurface lateral flow (dominates in moist/temperate climates) Shallow subsurface waters (in topographically convergent zones) Other land surface controls on surface hydrology: Terrain-controlled variations on insolation (slope-aspect-shading) Soil-bedrock interactions Courtesy the COMET Program

8 Hydrologically-enhanced Land Surface Models (Gochis and Chen, 2003, NCAR Tech Note) Explicit diffusive wave overland flow Groundwater discharge, reservoir routing & Dynamical Routing Methodologies Explicit channel routing 1-D Land Surface ModelS (e.g. Noah ) Explicit saturated subsurface flow fully distributed flow/head reservoir levels distributed soil moisture distributed land/atmo fluxes distributed snow depth/swe

9 Modeling Approach Advanced modeling framework philosophy Multi-scale Modularization Readily extensible Utilize high-performance computing Integrate rapidly evolving land surface information streams (e.g. remote sensing, scenario-based, paleo, etc.) Convenient and efficient I/O

10 Noah-distributed/NDHMS coupling with WRF: Standard WRF: 1-D land surface model (LSM) Coupled: Dist. Hyd. Models (DHMs)

11 NCAR-Research Applications Laboratory Highly modularized modeling architecture: Geographic/hydrographic data layers Generic Land Model Driver/ Coupler Land surface models (LSM) or DHMs Spatial disaggregation to routing grid Terrain routing: surface and subsurface Baseflow module Channel and reservoir routing Spatial aggregation to LSM grid

12 Output Products - Optimizing post-processing for operational and research environments - Capitalizing on maturity of netcdf I/O protocols, rapid integration with existing analysis and visualization packages - Standard WRF output grids plus spatially-continuous landscape hydrology fields (e.g. soil moisture, water table depth, streamflow, etc)

13 3. Output Visualization Tools: 1. GIS (Arc, GRASS): 2. Integrated Data Viewer (IDV) ( 3. Script-based languages (ncl, matlab, GrADS, IDL)

14 Outputs: Quantitative information on spatially distributed, hydrologic features : Full network streamflow/water depth

15 Suggestions for Hydrometeorological Studies: GPS water vapor retrieval for improved, continuous, real-time airmass characterization... Accelerate use of models for improved characterization of seeding regimes Include and synthesize more hydrological observations to assess wx mod impacts including (streamflow, gw levels, soil moisture) Expand surface hydromet network to include more hydrometeor information (disdrometers, k-band, gauges, hail sensor) to help assess microphysical impacts of seeding... Better utilize airborne platforms for surface remote sensing (e.g. thermal and MW imagergy) to assess 'wetness'and vegetation productivity