The first task is to open the forecast for this workshop and view results.

  1. Launch CWMS.
  2. Click on File | Open Watershed and select Workshop_HEC_RussianRiver.
  3. Navigate to the Modeling Module by selecting the Modeling tab in the study window.
  4. Select the Forecast menu option and choose Open. In this window, select the forecast titled HEC-HMS Model Calibration in CWMS
  5. You should see a map of the watershed and forecast information as shown below. 
    CAVI - Modeling Tab Overview
  6. Notice the QPF HEC-MetVue alternative is being skipped in the compute sequence. This is because the HEC-MetVue alternative has already been successfully computed for the forecast. 
  7. Notice the background map contains map layers for all model alternatives and time series icons showing flow observations. You can turn some off these visual layers to help you focus on specific tasks. Go to the Maps menu and choose Map Layers. Within the Map Layers editor, expand the tree node for Model Schematic and uncheck FIA and RAS model information, as shown below. You can turn these back on when needed. You can also turn off the Internet Map. Click the Close button to close the Map Layers editor.
    Map Layer Window
  8. The following figure shows the Modeling map after some of the map layers were turned off. Turning off some of the layers will help you access results from the map interface more efficiently. 
    Modeling Map after Turning off Map Layers
  9. Run the Daily Forecasting - 1HR HEC-HMS alternative. You will notice the HEC-HMS forecast run takes about 15 seconds to complete. 
  10. From the CAVI, Zoom in to Coyote Lake (Lake Mendocino), right click the mouse when the curser is on top of the reservoir, and choose to view the Graph for the HEC-HMS reservoir element. 
    How to Access HMS Plot from the CAVI Map Window
  11. Notice the model does a poor job simulating inflow and reservoir storage/elevation. This is due to a number of issues, including incorrect initial reservoir storage and poor simulation of inflow into the reservoir. 
    Initial HEC-HMS Results at Coyote Reservoir
  12. The following figure shows other locations with observed flow/elevation. 
    Key Locations with the Russian River watershed
  13. Open the Summary Table for the Calpella Gage junction and Hopland Gage junction and answer the following two questions.

What is the Percent Bias at the Calpella Gage junction element? This junction is located upstream of Lake Mendocino, the first USGS gage location in the figure above.

16.72 %

The Nash-Sutcliffe metric is helpful for identifying how well the model performs. A Nash-Sutcliffe of 1 means the model is able to perfectly match observations. Generally, a value greater than 0.7 means the model performance is good. Your goal is to have a Nash-Sutcliffe metric close to 1. 

What is the Nash-Sutcliffe metric for the Hopland Gage junction?

0.33

Prior Task(s):


Current Task:

Task 1: Open the Forecast and View Initial Results

Next Task(s):

Task 2: Import Existing Forecast Adjustment Factors for a Better Starting State