1. Plan Elements

    A. Model Simulations:

         Participants will generate hydrographs in two ways:

        1) Simulations using uncalibrated versions of their model.

        2) Simulations using models calibrated at basin outlet.

            NEXRAD data will be the precipitation forcing for all simulations.

            a) Participants will test their models on basins (200-2500 km2) to produce basin    outlet hydrographs.

            b) Where observed data are available, models will also produce a 'blind' simulation  at interior sub-basin points as a test of providing answers at ungaged sites.

                Participants will not perform explicit calibration above these points. See Test Basins for a listing and maps of the proposed interior sites.

            c) Models will produce simulations at HL-specified interior ungaged points to assess variability of predictions amongst models.

    B.    Models will be run in continuous retrospective simulation mode. Calibration and verification periods will be specified (See Modeling Instructions).

    C.    Basins will be limited to those used by HL's distributed modeling research.

    D. Basic data sets will be provided by HL on its web or ftp site.

    E. Participants will model one or more basins to produce a deterministic simulation.

    F. Participants will submit their simulations to HL in a (to-be-announced) standard format. HL will produce a comprehensive analysis of all simulations compared to observed data and lumped SAC-SMA simulations. This analysis will be presented at the HL-hosted workshop.

    G. Simulations from participants' models will be compared to those generated from a calibrated lumped SAC-SMA model.

    H. It is envisioned that a paper describing the results of the workshop will be submitted to a peer-review journal. Participants will be coauthors. It is hoped that a special issue of a journal would be dedicated to the results of DMIP.

    I. Evaluation Criteria: standard statistical measures for hydrograph comparison will be used.
 

2. Data Types Provided by HL

    A. DEM: resolution is 400 m in Albers Equal Area Projection. Higher resolution data such as the 30 m data from USGS could also be made available. Participants are free to use other DEM data.

    B Basin boundary LAT/LON pairs.

    C. LAT/LON location of interior computational points.

    D. Hourly streamflow data from USGS.

    E. NEXRAD Stage III xmrg files and utility programs.

    F. NRCS soils data (derived by D. Miller from STATSGO).

    G. Energy forcing fields (possibly from NCEP regional re-analysis).

    H. Vegetation.

    I. NDVI-5 Greenness Fraction Data.

    J. Others, as donated by participants.

    Participants needing other data will be responsible for obtaining them.
 

3. Workshop at the Office of Hydrologic Development (OHD) (formerly the Office of Hydrology (OH)): HL will 'host' a workshop after a specified period of time where participants will present their results and discuss the following:

    A. Model overview

    B. Model parameterization

    C. Model calibration

    D. Computational time

    E. Comparison Statistics:

        1) at parent basin outlet

        2) at interior points where observed streamflow data are available

        3) HL-designated points for inter-model variability assessment

            Comparison statistics will be generated using observed flow records and the   calibrated lumped application of the SAC-SMA model.

    F. Future modeling studies; publication of results; special issue of a journal.

4. Funding: HL will "host" this intercomparison, not "support" it, i.e., HL will supply the organizational legwork but participants should look for some funds from their own or other organizations.