CE 374K Final Exam Spring 2001

Hydrology

There are three questions on this exam. They are of equal credit. Do all three questions. For questions (1) and (2), prepare a 2-page typed theme paper. Question (3) can be answered with a combination of hand computations and spreadsheet output. Staple the three answers together in the order of the questions, and turn in the result to the EWRE secretary in ECJ 8.612 by 5PM on Thursday, May 10. This is a take-home exam. You are honor bound not to discuss this exam with your colleagues in the class. Your answers should be the result of your work and thought alone. Be assured that if essentially the same idea appears in answers from more than one person, it is fairly easy to recognize that when the grading is being done. If that happens, it is not clear from whom the idea originated and who is just using somebody else’s knowledge. So, keep your ideas to yourself!

What I am looking for in grading your answers is:

· Knowledge of the facts. Make sure you lay out the facts of what was covered in the relevant class lectures and readings before you start speculating about what could be done or should be done in the future

· Thoughtful evaluation. How do you evaluate the advantages and limitations of the principles, methods and data that have been used? How does the knowledge you’ve learned in this class relate to the world around us? I am looking for a sense of reflection here, of seeing you set individual situations and facts in a larger context in an intelligent way.

Questions

1. Fundamental Principles of Hydrology

Choose three core principles or equations that you consider to be fundamental to hydrologic analysis. Describe these principles or equations, explain how they are used and why you chose them as your core principles or equations. Draw a diagram that relates the other main topics and ideas in the course to the ones you have selected as your three core principles or equations. In answering this question, please keep in mind these factors:

• There is no unique answer to this question. What I am looking for is your logic and sense of understanding the course as a whole, rather than in its parts.
• Cover the whole course. Don’t choose your three core principles or equations from one section of the course
• Don’t choose one of your core principles as a special case of another. The core principles should be substantially independent of one another

2. Applications of Advanced Technology in Hydrology

There have been a number of presentations in class about the applications of advanced technologies in hydrology, including lectures on GIS Hydrology on Jan 23, Mar 29, Apr 17, Corps of Engineers simulation models on Mar 20, Mar 27, Mar 29 and new concepts for urban stormwater on Apr 19 and Apr 26. I would like you to make a summary of the key ideas that you see emerging that will influence the practice of hydrology in future years. How will GIS impact the practice of hydrology? What are the key national data sets that are being developed to support hydrologic modeling? What are the capabilities of new hydrologic simulation models and how can they be linked so that the output of one can be used as the input of another? How could these new technologies be implemented by a city to systematically support hydrologic analysis for many individual land developments in a city?

3. Design Storm Rainfall for Lago Vista

You have been appointed as the drainage engineer for Lago Vista, Texas, and one of your tasks is to develop a design rainfall estimates for your city. If you use Spreadsheet computations to answer this question, be sure to include at least one fully worked out computation that shows how a point in the spreadsheet was developed. Spreadsheet results alone are insufficient since you must document the sequence of the work that you did to obtain the results you present.

Do the following:

(a) Develop intensity-duration-frequency curves for storms of 5 minutes to 1 hour duration and return periods of 2, 5, 10, 25, 50, 100 years for Lago Vista. Draw a graph showing these six intensity-duration-frequency curves.

(b) Choose the 25 year return period curve and develop from this a 1 hour design storm hyetograph in 5 minute increments. In appearance, the result should look similar to the one for Denver in Figure 14.4.1 of Applied Hydrology.

(c) What is the chance that during the next 10 years a one hour duration storm will occur having the rainfall depth equaling or exceeding the value that you’ve determined in (a) and (b)?

Location of Lago Vista