An 8 km² watershed has a time of concentration of 1. 0 hour. Use HEC-HMS to determine the direct runoff for a storm (rainfall hyetograph given in Table 12. 6) using the SCS UH method.

a. You must create new basin, Meteorologic, and Control Specifications files either in the same project or in a new project.

b. You will need only one subbasin element in the basin file with area and SCS hydrograph details. You will only need the transform method. Specify None for loss method (input provided is excess rainfall) and baseflow.

c. The input to the Meteorologic file involves using the Time Series Data Manager from the Components menu. This will add a time series data folder in the watershed explorer and you will expand this folder to specify the rainfall hyetograph. When you edit the Meteorologic model in the component editor, you will use the Specified hyetograph (default) method. You will then click on the specified hyetograph option in the watershed explorer and link the time series data to the Meteorologic model.

d. In the Control Specifications model, use 10-minute time interval and 12-hour simulation time (end time = 12 hours past start time).