# UTPA STEM/CBI Courses/Applied Hydrology/Hydrograph

Course Title: Applied Hydrology

Lecture Topic: Unit Hydrograph

Instructor:

Institution:

## Backwards Design

Course Objectives

• Primary Objectives- By the next class period students will be able to:
• To understand the importance, definition and application of unit hydrograph.
• Sub Objectives- The objectives will require that students be able to:
• To define unit hydrograph and derive unit hydrograph from rainfall and runoff data.
• To determine direct runoff hydrograph from any storm event using unit hydrograph.
• To derive direct runoff by substituting baseflow from runoff data.
• To determine the design hydrograph for a given excess rainfall.
• To understand lagging process to determine the design hydrograph.
• Difficulties- Students may have difficulty:
• Identifying unit hydrograph and general hydrograph.
• Assumptions of unit hydrogaph which is very essential to define unit hydrogaph.
• Calculating the depth of direct runoff over a given watershed.
• Determining direct runoff from unit hydrograph, especially in different time interval.
• Real-World Contexts- There are many ways that students can use this material in the real-world, such as:
• Developement of any design hydrograph of outflow of a given watershed contributing of any rainfall.
• Deriving Basin watershed runoff characteristics.

Model of Knowledge

• Concept Map
• Unit hydrograph deifinitions
• Concept
• Concept by Sherman
• Assumptions and limitations
• Storm occurrence and distribution
• Storm duration and direct runoff limitation
• Derivation of unit hydrograph
• Baseflow separation from runoff
• Depth of direct runoff over watershed
• Duration of effective rainfall
• Application of unit hydrograph
• Contribution of rainfall
• Lagging method
• Total outflow design hydrograph
• Content Priorities
• Enduring Understanding
• Concept and definition of unit hydrograph "direct runoff for any storm produces 1 inch of net rain".
• Understanding basic assumptions to require to derive unit hydrograph.
• Important to Do and Know
• Understand assumptions and limitations of unit hydrograph instead just to know how to derive unit hydrograph.
• How to derive and apply unit hydrograph.
• Worth Being Familiar with
• Relations between hyetograph and hydrograph.
• Components of hydrograph and baseflow separation.

Assessment of Learning

• Formative Assessment
• In Class (groups)
• Discussions involving development of a hydrograph from an unknown watershed.
• Homework (individual)
• Required data for composing unit hydrograph.
• Summative Assessment
• In class quizzes over lesson.
• Determine unit hydrograph using given runoff streamflow data.
• Determine design hydrograph using the deriven unit hydrograph.

## Legacy Cycle

OBJECTIVE

By the next class period, students will be able to:

• Perform basic engineering estimations related to their field of study.
• Understand the importance of engineering estimation as a first step towards solving more complex engineering problems.

The objectives will require that students be able to:

• Be familiar with the basic engineering units and unit conversion factors in the three different unit systems.
• Relate conventional units to unconventional units as part of the engineering estimation techniques.

THE CHALLENGE

You watched TV news last night. The weather anchor said, "UTPA has been flooded and most of parking lots have been submerged by 100-yr frequency storm!!!" You would like to estimate the amount of flood from UTPA as a civil engineer. How should this problem be approached?

All you You live in Edinburg, TX where the weather is warm all year long. It is also extremely hot in the summer. You notice in January that your car air-conditioner is not working as efficiently as before. You ignore the problem since the air-conditioner is still working and the weather is not hot yet. The problem persists and you notice that the performance of the air-conditioner is getting systematically worst. In July, you take your car for a check up and the mechanic tells you that you have a refrigerant leak at a rate of one drop every two minutes. The mechanic also explains that since your car is an older model it uses R22 refrigerant which can't be purchased in the US. The mechanic explains that he can fix the leak but you will have to provide him with R22 refrigerant which can only be purchased from Mexico City. You would like to estimate the amount of referigerant that has leaked from your car-refrigeration system before you make a purchase. This is important because you do not want to make the trip to Mexico City and not buy enough refrigerant. You would also like to avoid buying more than you need (consider that one gallon of R22 Refrigerant costs \$50 and that they only sell it in half gallon increments).

GENERATE IDEAS

text

MULTIPLE PERSPECTIVES

text

RESEARCH & REVISE

text

text

GO PUBLIC

text

## Pre-Lesson Quiz

Various material can be tested here, depending on time constraints.