CIV E 634 - SURFACE WATER HYDROLOGY
SPRING 2005
HOMEWORK 1:   EVAPORATION

  1. Derive the Penman equation (Eq. 2-36, page 46).

  2. Verify Example 2-5 in the book by running PENMAN in onlinehydro.sdsu.edu.

  3. Calculate the evapotranspiration rate of the reference crop (clipped grass 0.12-m high) by the Penman-Monteith method for the month of March, with the following atmospheric conditions: air temperature Ta = 15 oC; net radiation Qn = 600 cal/cm2/d; wind speed v2 = 150 km/d; relative humidity RH = 70%; and atmospheric pressure = sea level (1013.2 mb).

  4. Verify your results of Problem 3 by running PENMAN-MONTEITH in onlinehydro.sdsu.edu.

  5. Using PENMAN-MONTEITH, study the sensitivity of the reference crop evapotranspiration to the relative humidity. Vary RH between 30% and 90% and report the results. What is the ratio of ETo for RH= 90% to RH= 30%?

  6. Use THORNTHWAITE in onlinehydro.sdsu.edu to calculate the annual PET for Ramona (32oN) with the following mean monthly temperatures (January to December): 12. 14. 16. 18. 20. 22. 21. 19. 17. 15. 13. 11.

  7. Verify Example 2-6 in the book by running BLANEY-CRIDDLE in onlinehydro.sdsu.edu.

  8. Verify Example 2-7 in the book by running PRIESTLEY-TAYLOR in onlinehydro.sdsu.edu.