University of Central Florida Civil and Environmental Engineering CWR4101 Hydrology Lecture 6 - Hydrograph Generation

The student should have the ability to;

• Calculate peak flow using the rational formula (Q = CiA).
• State the 4 assumptions for the rational equation.
• Define Unit Hydrograph.
• Explain how a unit hydrograph relates to watershed characteristics.
• Generate a synthetic unit hydrograph using the SCS method for any peak attenuation factor.
• Generate a watershed hydrograph by hand calculations using the following methods;
  • Unit Hydrograph and Rainfall Excess
  • Contributing Area Method
  • Clark Method
  • Santa Barbara Urban Hydrograph Method
• Define and identify the following on a plot of a streamflow hydrograph;
  • Lag Time
  • Time to Peak
  • Time of Concentration
  • Recession Time
  • Base Time
• Identify the following stream types from a plot of annual flow rates;
  • perrenial
  • intermittent
  • ephemeral
• Identify stream order from a topographic map of a watershed.
• Use empirical relationships to determine;
  • Drainage area from stream order
  • Stream length vs. watershed area
  • Discharge vs. watershed area
  and also determine coefficients for these empirical relationships using actual data and regression methods.
• Use flow separation techniques to separate runoff, interflow, and base flow for stream flow data.
• Using actual rainfall and runoff data calculate a unit hydrograph for a watershed. (Example Shown)

• Wanielista - Chapter 6
• Viesmann and Lewis - Chapter
• Singh - Chapters
• Ponce
• Linsley, Kohler, and Paulhus

• Class Notes #1
• Class Notes #2
• In Class Lecture
• Generation of Rainfall Excess
• Creating an SCS Unit Hydrograph

• Section 6.6.1 problems all