Unit 4. Urban Landscapes and Water Use
Unit 4 Learning Outcomes
After completing Unit 4, students will be able to:
- Discuss the variation in evapotranspiration with temperature, relative humidity, wind and available water (Activity 4.0)
- Relate plant evapotranspiration to plant consumptive use of water (Activity 4.0)
- Estimate irrigation needs of different types of vegetation based on given plant factor and reference evapotranspiration rates (Activity 4.1)
- Design an urban landscaped area and evaluate its water use over a summer growing season (Activity 4.1)
- Relate water-efficient landscaping to water sustainability in cities (Activity 4.3)
Context for Use
Description and Teaching Materials
Unit 4 uses the flipped classroom approach and is designed for one or two 75-minute class periods. The instructor can tailor the design project (Activity 4.2) to be completed in one class period or extend through two class periods. Before the class period, students watch a video and answer questions (Activity 4.0) about how evaporation and evapotranspiration (ET) vary with location and climate, and consider a basic water balance between ET and precipitation at different locations to estimate plant irrigation needs. A short quiz (Activity 4.1) is provided to assess students' understanding of the pre-class activity. During the class period(s), the students design an urban landscaped area and estimate irrigation needs for a water-efficient landscape plan compared to turf landscaping (Activity 4.2). Following the landscape design activity, students add to their mind map of an urban water system (Activity 4.3). Discussion questions (Activity 4.4 or at end of handout for option 1, Activity 4.2) can be used for class discussion or homework.
Activity 4.0 - Pre-class: Introduction to ET and landscape water use
Prior to the class session, students shall complete the following required activities:
- Watch the following video: Evapotranspiration and Landscape Plant Water Needs (17:27)
- Or download video from: Video - Evaporation and Landscape Plants Water Needs (MP4 Video 102.7MB Jan5 16)
- NOTE: Instructors can also download the PowerPoint slides used in the video (PowerPoint 2007 (.pptx) 5.7MB Sep22 16)
- Supplemental optional videos:
- Basic video explaining evapotranspiration: Weather Wise: Evapotranspiration (approximately 4 min)
- Video about lawn irrigation and ET rates: ET Rates – Water Smart Tips (approximately 2 min)
- Video demonstration of ET gage (atmometer) for measuring reference ET: CoCoRahs video about measuring ET (approximately 2 min)
- Complete the student handout. The questions will be discussed during the class period.
- Activity 4.0 - Student Handout (Microsoft Word 2007 (.docx) 1.6MB Sep22 16)
- For instructor use only:
(10 min) Activity 4.1 - In-class: Optional Quiz and Discussion
- Optional short multiple-choice quiz that can be given in class to assess students' understanding of Activity 4.0
- For instructor use only: Activity 4.1 Quiz Solutions -
- Class discussion of pre-class Activity 4.0 video and questions
(60 min) Activity 4.2 - In-class: Group Landscape Design Project
Activity 4.2 is a group activity in which students compute the water use for a growing season for two different landscape designs to compare the amount of water used. First, they compute the water use for a turf landscape. Then they design a water-efficient landscape and compute the water use of their design. They then compare their water-efficient design with the turf landscape and asses the effectiveness of their design. Students can complete the discussion questions on their own for homework if there is not enough time to finish in class.
The activity is prepared to be used with or without computers in the classroom. If computers are available, students can download their own data and perform computations in spreadsheets. If computers are not available, data are provided, and a worksheet is provided so students can do the computations in class.
The instructor may choose between two design projects, both of which can be built on in later units of the Water Sustainability in Cities module:
- Option 1: Single family residence backyard landscaping. The landscaping strategies used here can be scaled up for the subdivision design in Unit 9.
- without computers in the classroom where students compute irrigation demand for one month
- with computers in the classroom where students either use data provided for growing season in Fort Collins, CO, or download their own data and perform computations for irrigation demand for entire growing season in a spreadsheet.
- Option 2: Institutional building landscape design at University of Utah. This building is used again in Units 5 and 7. Computers are required for this option.
Option 1 - Single-family Residence Backyard Design
- Option 1a - Without computers in the classroom
- Student Handout (includes instructions and worksheet): Activity 4.2 - Option 1a - Student Handout (Microsoft Word 2007 (.docx) 116kB Sep22 16)
- Instructor Solution (For instructor use only):
- Option 1b - With computers in the classroom
Option 2 - Institutional Building at University of Utah (computer required)
- To give the students an idea of what different water use plants might look like for their water-efficient landscape design, you can provide each group with a color print-out of the Student Plant Handout: Activity4_2_Plant_Handout (Microsoft Word 2007 (.docx) 2.4MB Sep3 14)
- Rubric for assessing group design: Activity 4.2 - Rubric (Microsoft Word 2007 (.docx) 21kB Jul4 16)
(5 min) Activity 4.3 - In-Class: Mind Map
- Students add new concepts to their group mind map of an urban water system
Activity 4.4 - Homework: Discussion Questions
- These discussion questions are included in the Option 1 student handouts above, and can be used for homework or discussion. Students answer questions reflecting back on their group design project. The questions are included here as a separate document if you want to use them for homework:
- Activity 4.4 - Discussion Questions (Microsoft Word 2007 (.docx) 24kB Jul4 16)
- For answers to Discussion Questions see Option 1a instructor solutions above.
Teaching Notes and Tips
Activity 4.0 - Teaching Notes
Activity 4.1 - Quiz Solutions
Activity 4.2 - Teaching Notes
This activity can be conducted with or without computers in the classroom. The computations lend themselves to a spreadsheet, but data and worksheets are provided so the activity can be done by hand depending on time and facilities available. The activity is set up to use the growing season of May 1 through Sept 30, which is a 23-week season, but the activity could be adjusted to span just one month and still be effective. Weekly data are used because often landscape watering scheduling is done on a weekly basis. Students need to look at the landscape ET and precipitation for each week and consider if watering is necessary at all.
Option 1a - Without Computers:
If you do not have access to a computer in your classroom, you can use the example data provided in the student handout. The data tables are also included in Excel form.
Option 1a - With Computers:
This option utilizes spreadsheets for the computation. You have the option to use the ET and P data provided, or to have students download ET and P data depending on how much time you have. The Student Instructions handout includes an optional section that explains how to download data from Northern Water Conservancy District in Colorado. Other possible sources of ET data:
Excel spreadsheets are provided with all of the computations performed using data from Fort Collins, CO, and are blank so that students can perform their own calculations using the Fort Collins data.
Multiple choice questions are provided that can be used for a pre/post assessment. These questions assess basic understanding of evapotranspiration and its relationship to irrigation needs and water-efficient landscape design.
- Solutions to quiz (for instructor use only):
Assessment of other learning objectives can be accomplished by assessing the group design projects from Activity 4.2. A simple rubric is included for assessing the design exercise: Activity 4.2 - Rubric (Microsoft Word 2007 (.docx) 21kB Jul4 16)
References and Resources
Allen, R.G., L.S. Pereira, D. Raes and M. Smith, 1998, Crop evapotranspiration - Guidelines for computing crop water requirements - FAO Irrigation and drainage paper 56, Food and Agriculture Organization of the United Nations, Rome, Italy.
Detweiler, A.J., P. Griffiths, and R. Olson, 2005. An Introduction to Xeriscaping in the High Desert And Pictorial Plant Guide for Central & Eastern Oregon, Oregon State University Extension Service.
Hanson, R.L., 1991, Evapotranspiration and Droughts, in Paulson, R.W., Chase, E.B., Roberts, R.S., and Moody, D.W., Compilers, National Water Summary 1988-89—Hydrologic Events and Floods and Droughts: U.S. Geological Survey Water-Supply Paper 2375, p. 99-104.
Kjelgren, R., L. Rupp and D. Kilgren, 2000. Water Conservation in Urban Landscapes, HortScience, 35(6): 1037-1040.
Hattendorf, M.J. 2012. Northern Water Irrigation Management – Xeriscape Irrigation Recommendations.
Sanford, W. E. and D. L. Selnick, 2012. Estimation of Evapotranspiration Across the Conterminous United States Using a Regression with Climate and Land-Cover Data. Journal of the American Water Resources Association (JAWRA) 1-14. DOI: 10.1111/jawr.12010
St. Hilaire, R., D.A. Devitt, B.H. Hurd, B.J. Lesikar, V.I. Lohr, C.A. Martin, G.V., McDonald, R.L., Morris, D.R. Pittenger, D.A. Shaw, and D.F. Zoldoske, 2008. Efficient Water Use in Residential Urban Landscapes, HortScience, 43(7): 2081-2092.