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Learn how to analyze the costs, required inputs, and impacts of different landscape choices using the Value Landscape Engineering (VLE) model. Compare the lifecycle of two landscapes and find ways to reduce costs, labor, water use, and other inputs.
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Value LandscapeEngineering (VLE)Lifecycle Analysis David Rosenberg CEE 5460 – Water Resources Engineering
Learning Objectives • Describe modeled landscape lifecycle stages, components, inputs, and impacts • Enter input data for a landscape • Compare costs, required inputs and impacts for two landscapes • USU College of Engineering Wiki, or • http://vle.cuwcd.com/ CEE 5460
Why do this? • How much will your landscape cost to operate and maintain over the time you own the property? • How much water will you need each year and over the landscape life? • How much fertilizer and pesticides will you need? • How can you achieve a quality landscape andreduce landscape costs, labor, wateruse, and other inputs? CEE 5460
Applications to Date CEE 5460
Landscape Lifecycle Stages • Start-up (first year) • Site preparation • Installation • Recurring (successive years) • Annual operations and maintenance (O&M) • Replace features that die or break • Site prep. • Installation • O&M • O&M • O&M • Replace • O&M • O&M • O&M • Replace • O&M • O&M • O&M Economic life Time CEE 5460
Landscape Components Modeled • Vegetable gardens • Turfgrass • Hardscape • Trees • Perennials • Annuals • Shrubs • Ground covers • Mulches
Landscape Components (cont.) • Irrigation system • Maintenance equipment • Site prep. equipment • Rock walls • Decking • Fencing • Lights
Using the VLE Model • Download the Excel 2007 Workbook • Enable Macros • Select the ‘Cost Summary’ worksheet • Enter initial assumptions • Enter plant coverage and configurations for up to 3 landscapes • Enter purchase prices and lifespans • Select the desired Maintenance Level • Examine results • Modify assumptions CEE 5460
Working with the model Landscapes Input Data Intermediary Calculations Final Results CEE 5460
4. Enter Initial Assumptions • Apply to all landscapes • Economic life (Row 6) and Local ET (Row 20) are key! • Enter values or use default settings (for Wasatch Front, UT)
5. Enter Plant Coverage & Configuration • Total landscaped area in square feet (Row 24) • All other plant coverage as a percentage
5. Enter Plant Coverage (cont.) • Counts of trees and shrubs • Placement of trees and shrubs (in other features)
6. Purchase Prices and Lifespans • Drop-down lists: default price options • Purchase Price = cost per unit • Lifespan = number of years until feature must be replaced • Required units= calculated from prior input CEE 5460
6. Purchase Prices and Lifespans (cont.) • Drop-down lists for plant irrigation zones also set irrigation efficiency! CEE 5460
7. Maintenance Level (Row 138) CEE 5460
8. Results • Annual O&M (Row 140) and Replacement (Row 158) costs • Investment (Row 163) and Lifecycle (Row 168) analyses • Details on Input/Impact worksheets! CEE 5460
Enter and Compare Now lets use the VLE Model!
Example 1 • How will the 25-year lifecycle cost, required water and labor change if the DIY homeowner replaces the 5 areas of cool season (Kentucky) turfgrass with warm season (Buffalo) turfgrass? (see plan next slide) • Property area = 10,516 sq. ft.; Local ET = 30 inches/year • Trees (all in perennial beds) • 2 slow growing trees (Japanese maple and white birch) • 3 conifer (Skyrocket juniper) • 3 fast growing trees (Eastern redbud, Honeylocust, & Tulip) • 1 drought tolerant (Amur Chokecherry) • Sprinkler irrigation system (70% efficient) CEE 5460
Example #1 CEE 5460
Example 2 • How will the 20-year lifecycle cost, required water and labor change if the DIY homeowner • Replaces cool season (Kentucky) turfgrass area #4 with drought tolerant perennials? • Trees on the property: • 6 fruit • 20 fast-growing • 1 conifer di = drought intolerant CEE 5460
Example #2 CEE 5460
Model Limitations • Model default data for Utah • Verified for SLC, Utah • Substitute site-specific data for default settings • Changes in model inputs (initial assumptions, planting area, prices, etc.) affect results • Model results generally accurate to 30% • Focus on relative changes CEE 5460
Conclusions • VLE provides lifecycle analysis of landscape choices • Considers all activities over the landscape life • Compare impacts and required inputs for a current landscape and changes to that landscape • Adjust landscape components to identify a landscape that saves water and money CEE 5460
Additional Resources • VLE Wiki or http://vle.cuwcd.com • User’s Manual • Spreadsheet Template • Spreadsheet with 3 worked examples • Rosenberg et. al (2011). "Value Landscape Engineering: Identifying Costs, Water Use, Labor, and Impacts to Support Landscape Choice.“ Journal of the American Water Resources Association, 47(3), 635-649. http://dx.doi.org/10.1111/j.1752-1688.2011.00530.x CEE 5460