Answer only ten (10) questions.

1. What is deep percolation in the context of L'vovich's water balance? Why is deep percolation only a small fraction of precipitation? Explain the physical basis for this behavior.

2. Contrast the contributions of Dalton, Penman, Monteith and Shuttleworth-Wallace in evaporation modeling.

3. Discuss the controversy of initial abstraction in the runoff curve number method.

4. Why is the Mockus approach to runoff generation, for the most part, better than Horton's? Explain.

5. Why is the time of concentration calculated by the kinematic wave model likely to be much less than that calculated with a storage concept or diffusion wave?

6. What is the mean albedo of the Earth's surface? How does albedo vary from rain forests to deserts? Is it possible for humans to change the albedo of the ground surface? How?

7. Discuss the apparent reason for the persistence of the Sahel drought of 1970-85.

8. What are the four physical processes responsible for the formation of rain?

9. What is the root cause of El Niño? How often does an El Niño event likely to recur? What are the effects of an El Niño event?

10. How much is the mean annual global terrestrial precipitation, in mm? How was this value obtained? At what part of the climatic spectrum are droughts likely to be more persistent? Give an example.

11. Bonus question (may replace any of the above): Why is the cybernetic approach to the hydrologic cycle better than the cause-effect approach? What fact of nature supports the argument in favor of the cybernetic approach? Explain.