53:078 Principles of Hydrology (Spring 2004)
Problem #23
HEC-HMS Simulation for Ralston Creek (July 1972 Flood)

In this assignment, you will be using the Hydrologic Modeling System (HEC-HMS) Version 2.2.1 to simulate streamflows on the North Branch Ralston Creek. Before you begin, please review the following:

Use HEC-HMS to simulate the 17-18 July 1972 flood (Run-1) on the North Branch Ralston Creek using the f-index (i.e., the Initial/Constant Method in HEC-HMS) for computing rainfall excess (direct runoff) and streamflow.

  1. Select the f-index for this storm event and use it in the simulation (Hint: Use the value assumed in Problem #22).
  2. Determine the SCS time lag (tl) for the SCS Dimensionaless Unit Hydrograph and use it in the simulation.  (Hint: Use the value derived for North Branch Ralston Creek in Problem #22).
  3. Include a Summary Table of the simulated flood hydrograph (under View Results from the North Branch icon)
  4. Include a Time-Series Table of the simulated event (under View Results from the North Branch icon).
  5. Include a Graph of the simulated and observed flood hydrographs (under View Results from the USGS icon).

(Note: Assume that the initial loss is 0 and the percent impervious area is 0.0.  The resulting rainfall excess pattern from the HEC-HMS model should then be the similar that computed in Problem ##22 for this storm.)
Last changed on 03/29/04 by aab.